Differences

This shows you the differences between two versions of the page.

--- techtalk:ih:oil01 [2024/02/08 23:09]
52.70.240.171 ↷ Links adapted because of a move operation
+++ techtalk:ih:oil01 [2024/02/21 19:01] (current)
hippysmack
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 ====== IH: Oiling & Lubrication ======
 ====== Engine Oil System ======
-More pathway details at [[techtalk:ih:oil05|Engine Oil Routes]]
+The Sportster Oiling Cycle is defined in the FSMs. \\
+However, that description is vague in some of the intricate transitions of the oil path in the engine. \\
+This page is an attempt to clarify some of the gray areas from the FSM's descriptions with further description and pictures. ((Hippysmack of the XLFORUM)) \\
-And in the REF section of the Sportsterpedia, see these: \\
+Links to other Oiling pages in the Sportsterpedia: \\
   * [[techtalk:ref:oil05|Engine and Primary Oil System Modifications]]
   * [[techtalk:ref:oil04#sportster_oil_pressure_57_to_present|Sportster Oil Pressure (57 to Present)]]
   * [[techtalk:ref:oil15|Installing an Oil Pressure Gauge]]
+  * [[techtalk:ih:oil06#oil_leaks|Oil Leaks]]
+  * [[techtalk:ref:oil10|Wet Sumping]]
-====== Engine Oiling ======
+Oil Path Drawings: Click on a drawing below to enlarge. ((drawings by Hippysmack)) \\
-=== General Statement ===
-The Sportster Oiling Cycle is defined in the FSMs. \\
+{{:techtalk:ih:oil:1957-1976_sportster_oil_feed_and_return_path_by_hippysmack.png?direct&500|}}  \\
-However, that description is vague in some of the intricate transitions of the oil path in the engine. \\
-This page is an attempt to clarify some of the gray areas from the FSM's descriptions with further description and pictures. ((Hippysmack of the XLFORUM)) \\
+{{:techtalk:ih:oil:1977-1985_sportster_oil_feed_and_return_path_by_hippysmack.png?direct&450|}} \\
 ====== Engine Oil Cycle (1976 and Earlier) ======
+Oil is gravity fed from the oil tank to the oil pump. ((1959-1964 HD Sportster FSM pg 3A-15)) A check valve in the oil pump prevents the oil from draining into the engine by gravity. Then, the oil pump supplies pressurized oil into a hole in the cam cover. That pressurized oil is forced up the lines (between the cylinders) to the rocker box by the oil pump. That is the vertical end of responsibility (pressure wise) for the oil pump. In the rocker boxes, oil gathers and splashes over rocker arm bearings and rods, valve stems, valve springs and pushrod sockets. Before the oil reaches the rocker lines, it splits off to a hole through the pinion shaft (to get to the lower rod bearings). This is the horizontal end of responsibility (pressure wise) for the oil pump. From here on, oil travels through the engine by way of gravity, vacuum and splash motion. \\
-  * Oil is gravity fed from the oil tank to the oil pump. ((1959-1964 HD Sportster FSM pg 3A-15))
-    * A check valve in the oil pump prevents the oil from draining into the engine by gravity.
+Oil drains from the heads through passages in each cylinder. Then it flows into two holes in the base of each cylinder while lubricating the cylinder walls, pistons, rings and main bearings.((1959-1964 HD Sportster FSM pg 3A-15)) Oil flows from the rocker boxes into the gearcase compartment through the pushrod tubes. Parts lubricated by this include the pushrods, tappets, tappet guides and tappet rollers and cam gears. \\
-  * Then, the oil pump supplies pressurized oil into a hole in the cam cover.
-    * That pressurized oil is forced up the lines (between the cylinders) to the rocker box by the oil pump.
+Oil accumulated in the crankcase base is scavenged by the flywheels to the breather oil trap. The rotary breather valve is timed to open on the downward stroke of the pistons. This allows crankcase exhaust air pressure to expel scavenge oil from the crankcase breather oil trap into the gearcase. The breather valve closes on upward stroke of the pistons, creating vacuum in the crankcase.
-    * That is the vertical end of responsibility (pressure wise) for the oil pump.
+This splash oil blown from the crankcase to the gearcase lubricates the generator drive gear, cam gears and cam bearings. Crankcase exhaust air escapes from the timing gearcase through the outside breather tube.((1959-1964 HD Sportster FSM pg 3A-15)) Any oil still carried by exhaust air is separated form the air by an oil slinger on the generator drive gear.((1959-1964 HD Sportster FSM pg 3A-15))
-  * In the rocker boxes, oil gathers and splashes over rocker arm bearings and rods, valve stems, valve springs and pushrod sockets.
+Gearcase oil flows through the fine mesh oil strainer preventing foreign particles from entering the scavenge section of the oil pump.((1959-1969 HD Sportster FSM pg 3A-15)) Engine oil returns to the oil tank by the scavenge side of the oil pump and also supplies oil to the rear chain oiler. \\
-  * Before the oil reaches the rocker lines, it splits off to a hole through the pinion shaft (to get to the rod bearings).
-    * This is the horizontal end of responsibility (pressure wise) for the oil pump.
-  * From here on, oil travels through the engine by way of gravity, vacuum and splash motion.
-    * Oil drains from the heads through passages in each cylinder.
-      * Then it flows into two holes in the base of each cylinder while lubricating the cylinder walls, pistons, rings and main bearings.((1959-1964 HD Sportster FSM pg 3A-15))
-    * Oil flows from the rocker boxes into the gearcase compartment through the pushrod tubes.
-      * Parts lubricated by this include the pushrods, tappets, tappet guides and tappet rollers and cam gears.
-    * Oil accumulated in the crankcase base is scavenged by the flywheels to the breather oil trap. \\ The rotary breather valve is timed to open on the downward stroke of the pistons. \\ This allows crankcase exhaust air pressure to expel scavenge oil from the crankcase breather oil trap into the gearcase. \\ The breather valve closes on upward stroke of the pistons, creating vacuum in the crankcase.
-  * This splash oil blown from the crankcase to the gearcase lubricates the generator drive gear, cam gears and cam bearings.
-  * Crankcase exhaust air escapes from the timing gearcase through the outside breather tube.((1959-1964 HD Sportster FSM pg 3A-15)) Any oil still carried by exhaust air is separated form the air by an oil slinger on the generator drive gear.((1959-1964 HD Sportster FSM pg 3A-15))
-  * Gearcase oil flows through the fine mesh oil strainer preventing foreign particles from entering the scavenge section of the oil pump.((1959-1969 HD Sportster FSM pg 3A-15))
-  * Engine oil returns to the oil tank by the scavenge side of the oil pump and also supplies oil to the rear chain oiler.
 ====== Engine Oil Cycle (1977 to 1985) ======
+Oil is gravity fed to the gerotor type oil pump. Oil enters the feed section and fills a cavity under the feed pump. Oil is transferred from the inlet cavity to a one way check valve located in the outlet line. ((1970-1978 HD Sportster FSM pg 3-7)) The check valve prevents gravity oil drainage from the oil tank to the engine and acts as a restriction to activate the pressure switch. The check valve is set to open between 4 psi and 6 psi of oil pressure. ((1970-1978 HD Sportster FSM pg 3-7)) As the oil pump pressurizes, it causes the oil pressure indicator light, sending unit to activate and the check valve opens. With the check valve open, oil flows into the right case half through a hole located in the oil pump gasket surface and into the gearcase cover passage through a hole in the gearcase cover gasket. ((1970-1978 HD Sportster FSM pg 3-7)) Oil is routed to the crankshaft and to the head areas. Oil enters a hole in the pinion gear shaft and travels to the right flywheel then through the flywheel to the crank pin. Oil is forced out of the crank pin through 3 holes located to properly lubricate the rod bearing assembly. ((1970-1978 HD Sportster FSM pg 3-7)) Oil that bypasses the pinion gear shaft travels upward through the gearcase cover to the right crankcase and through a channel in the crankcase to the overhead lines to both front and rear intake rocker arm shafts, lubricating the rocker arm shafts, bushings, intake valves and pushrods. ((1970-1978 HD Sportster FSM pg 3-7))
-  * Oil is gravity fed to the gerotor type oil pump. Oil enters the feed section and fills a cavity under the feed pump. Oil is transferred from the inlet cavity to a one way check valve located in the outlet line. ((1970-1978 HD Sportster FSM pg 3-7))
+Oil continues around a groove machined in the outside diameter of the large end of the rocker arm shaft and through the rocker arm arm cover to the exhaust rocker arm shaft lubricating the rocker arm bushings, valves and pushrods in the same manner as is described for the intake shafts. ((1970-1978 HD Sportster FSM pg 3-7)) Oil collected in the pushrod area of the heads flows down the pushrod covers to lubricate the lifters. The lifter's rollers are lubricated by oil draining into the gearcase through the 2 drain holes in the lifter bodies. ((1970-1978 HD Sportster FSM pg 3-7)) Oil collected in the valve spring pockets drains to the flywheel compartment through horizontal holes in the cylinders. Oil returning from the heads, rod assembly and gearcase collects in the sump area below the flywheels. ((1970-1978 HD Sportster FSM pg 3-5)) \\
-  * The check valve prevents gravity oil drainage from the oil tank to the engine and acts as a restriction to activate the pressure switch. The check valve is set to open between 4 psi and 6 psi of oil pressure. ((1970-1978 HD Sportster FSM pg 3-7))
-  * As the oil pump pressurizes, it causes the oil pressure indicator light, sending unit to activate and the check valve opens. With the check valve open, oil flows into the right case half through a hole located in the oil pump gasket surface and into the gearcase cover passage through a hole in the gearcase cover gasket. ((1970-1978 HD Sportster FSM pg 3-7))
-  * Oil is routed to the crankshaft and to the head areas. Oil enters a hole in the pinion gear shaft and travels to the right flywheel then through the flywheel to the crank pin. Oil is forced out of the crank pin through 3 holes located to properly lubricate the rod bearing assembly. ((1970-1978 HD Sportster FSM pg 3-7))
-  * Oil that bypasses the pinion gear shaft travels upward through the gearcase cover to the right crankcase and through a channel in the crankcase to the overhead lines to both front and rear intake rocker arm shafts, lubricating the rocker arm shafts, bushings, intake valves and pushrods. ((1970-1978 HD Sportster FSM pg 3-7))
-  * Oil continues around a groove machined in the outside diameter of the large end of the rocker arm shaft and through the rocker arm arm cover to the exhaust rocker arm shaft lubricating the rocker arm bushings, valves and pushrods in the same manner as is described for the intake shafts. ((1970-1978 HD Sportster FSM pg 3-7))
-  * Oil collected in the pushrod area of the heads flows down the pushrod covers to lubricate the lifters. The lifter's rollers are lubricated by oil draining into the gearcase through the 2 drain holes in the lifter bodies. ((1970-1978 HD Sportster FSM pg 3-7))
-  * Oil collected in the valve spring pockets drains to the flywheel compartment through horizontal holes in the cylinders. Oil returning from the heads, rod assembly and gearcase collects in the sump area below the flywheels. ((1970-1978 HD Sportster FSM pg 3-5))
-  * Oil collected in the sump area returns to the scavenger section of the oil pump through a passage located in the rear section of the pump. Oil flow to the pump is accomplished by the scavenger effect of the oil pump and the pressure created from the downward stroke of the pistons. ((1970-1978 HD Sportster FSM pg 3-7))
-  * Return oil fills a cavity above the scavenger section of the pump which transfers return oil to the outlet side of the pump and sends the oil back to the oil tank.
-  * All engine breathing is accomplished through the gearcase into the breather system. Any oil still carried by the exhaust air is centrifugally separated from the air by an oil slinger on the end of the generator drive gear shaft.((1970-1978 HD Sportster FSM pg 3-7))
-  * Crankcase exhaust air is routed through a one way check valve to the air cleaner.  ((1970-1978 HD Sportster FSM pg 3-7))
-====== Top End Oiling ======
+Oil collected in the sump area returns to the scavenger section of the oil pump through a passage located in the rear section of the pump. Oil flow to the pump is accomplished by the scavenger effect of the oil pump and the pressure created from the downward stroke of the pistons. ((1970-1978 HD Sportster FSM pg 3-7)) Return oil fills a cavity above the scavenger section of the pump which transfers return oil to the outlet side of the pump and sends the oil back to the oil tank. \\
-===== Cam Cover Oiling =====
-The oil going up to the top end not only passes by the bushing in the cam chest, but also is fed to and from the cam cover and through the cam cover gasket. ((XLFREAK of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/98031-suggestions-on-lack-of-oil-to-top-end/page2?t=831522&highlight=crankcase+pressure&page=2)) \\
-It is possible for the gasket to blow out and seal up the oil galley feed passages. \\
-Also if silicon was used on the cover, it is possible for that to break loose and stop up the passages. \\
-You can take the cover off and run a tap down all the threaded holes to clear out any obstructions. \\
-Also check that the face of the cover and case are not marred by some big scratch or dent. \\
-To get old silicone out of bolt holes, you can use an inflation needle for footballs/basketballs/soccerballs. ((rivethog of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/98031-suggestions-on-lack-of-oil-to-top-end/page2?t=831522&highlight=crankcase+pressure&page=2)) \\
-Cut the tip off of it then screw it into the end of an air blowgun. \\
-It's narrow enough that it doesn't block debris from getting out of the hole. \\
-|Oil path of 85 style cam cover ((photo by billeuze of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/115252-cam-fitment-question-on-ih-help-me-out-plz?t=1103082))|
+All engine breathing is accomplished through the gearcase into the breather system. Any oil still carried by the exhaust air is centrifugally separated from the air by an oil slinger on the end of the generator drive gear shaft. ((1970-1978 HD Sportster FSM pg 3-7)) Crankcase exhaust air is routed through a one way check valve to the air cleaner.  ((1970-1978 HD Sportster FSM pg 3-7)) \\
-|{{:techtalk:ih:oil:85_cam_cover_1_by_billeuze_annotated_by_hippysmack.jpg?direct&300|}}|
+====== Oil Feed System ======
+===== Sub Documents =====
+  * [[techtalk:ih:oil01a|Feed Oil Passages Through Pics]]
+The engine has a force-fed (pressure type) oiling system incorporating oil feed and return pumps in one pump body with a check valve on the feed side.
+===== Role of the Oil Tank =====
+[[techtalk:ih:oil04|Click Here]] to reference the Ironhead Oil Tank section in the Sportsterpedia. \\
+[[techtalk:ref:oil20|Click here]] to reference the Oil Tank Pressure page in the Sportsterpedia. \\
+**The oil tank is both an oil reservoir and air/oil separator**. Return oil comes into the tank carrying both air and oil. \\
+The oil drops to the bottom while air rises up and out the vent back to the cam chest. \\
+**From 1957-1978, the oil tank is also a housing for the oil filter on XL / XLH models**. XLCH models didn't have a factory installed oil filter. \\
+**Oil is gravity fed from the oil tank to the oil pump.** What that means is since the oil tank is higher than the pump, gravity pushes oil down to the pump inlet but not into a running motor. It's basically a byproduct of hanging the tank above the pump. Gravity does assist pump suction however. A pressure of less than 1/4 PSI was calculated in the link below as an example on a 1998 model Sportster setup. That 1/4 PSI is just for example only as elevation and oil density will slightly change that number. The point of stating that is there is very little (but needed) gravity oil pressure on the oil at the pump inlet. \\
+[[techtalk:ref:oil21#oil_tank_head_pressure|Click Here]] to read more on calculating Oil Tank Head Pressure at the pump in the REF section of the Sportsterpedia. \\
+**Pressure from gravity constantly pushes oil to the pump's inlet which helps the pump pick up oil through suction from there**. \\
+The higher the oil tank sits, the higher the oil level sits which increases the NPSHA which is the (Net Positive Suction Head Available) to the pump. \\
+[[techtalk:ref:oil21#npshr_vs_npsha|Click Here]] to read more on NPSHR vs NPSHA in the REF section of the Sportsterpedia. \\
+The pump requires a positive push of oil to the inlet cavity to function as designed. \\
+**Pressure from gravity is also the reason oil from the tank can leak down into the motor when the motor is shut down**. \\
+[[techtalk:ref:oil10#sit_sumpimg|Click Here]] to read more on Sit Sumping in the REF section. \\
+**It's not unusual to get air out the oil return line (to the tank).** ((aswracing of the xlforum https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-motor-top-end/135598-crankcase-pressure?t=1468237)) It's a dry-sump system with an oil pump that's designed to keep the engine sump as dry as it can. When there's no oil to suck up, it pumps air instead into the oil tank. That's the way it's supposed to work. \\
+**The oil tank vents separated air back to the gearcase**. The vent line from the tank mostly vents oil tank air back to the gearcase mixed with an oil mist. If the vent line is kinked or blocked, pressure will back up in the tank and pop the cap and splash oil everywhere. 1957-1966 XLH and 1958-1969 XLCH engines vent the oil tank to the gearcase by a hose attached from the oil tank to a fitting on the top of the engine behind the rear cylinder. There is a passage in the engine case that routes from there into the gearcase. 1967-up XLH and 1970-up XLCH engines vent the oil tank to the gearcase by a hose from the oil tank a 90° fitting on the rear of the gearcase cover. \\
+|  Oil tank vent fitting on 1973 XLH ((photo by Levi Luther of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/163679-lets-see-where-this-leads-me-73-sporty-project-and-re-build/page9?t=1759261&page=9))  |
+|{{:techtalk:ih:oil:1973_xlh_cam_cover_by_levi_luther.jpg?direct&300|}}|
+===== Role of the Oil Pump - Pressure =====
+[[techtalk:evo:oil03#evooiling_lubrication|Click Here]] to reference the oil pump section in the Sportsterpedia. \\
+The feed side of the oil pump forces oil to the engine to lubricate the lower connecting rod bearings, rocker arms and bushings, valve stems, valve springs, and pushrods (and cam gears on 1985 models only). The pressure side of the oil pump is non-regulated and delivers its entire volume of oil under pressure to the engine feed system. \\
+Different areas of the motor have different types of pressure applied and from different sources. ((bustert of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/196615-over-sized-oil-lines/page3?t=2073175&page=3)) ((Hippysmack)) \\
+The same applies to the oil pump. \\
+**Oil pump feed gear / gerotor vacuum sucks oil from the inlet cavity or attached hose respectively into the inlet cavity of the pump**. There is a vacuum created on the inlet cavity of the pump generated by the opening of the gears / gerotors when they rotate around to the inlet side of the pump. Vacuum is aided by the positive force of gravity from the higher hung oil tank as mentioned above. ((Hippysmack of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/196615-over-sized-oil-lines/page3?t=2073175&page=3)) Without vacuum, the pump would not be able to function properly and would starve the pump especially at higher RPM. As the volume between the feed gerotor (or gears respectively) increases with engine RPM, the suction on the feed line also increases. ((shanneba of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/196615-over-sized-oil-lines/page3?t=2073175&page=3)) Likewise with lower RPM, the suction decreases. \\
+Too low suction and the gear / gerotor cavities will not completely fill with oil especially on higher RPM and system oil volume will suffer. Too much vacuum and oil vapor may be pulled out of the oil stream and cavitate / damage the oil pump. Thankfully, the MoCo has designed the OEM oiling system in the Sportster to keep this from happening. \\
+**The oil pump pressurizes the oil delivered to the outlet cavity in the pump**. One teeth cavity of oil at a time is rotated from the inlet side to the outlet side in the pump. The closing of the teeth afterward combined with the next teeth full of oil continues squeezing (pressurizing) the outlet cavity. The faster the rotation, the higher the pressure that is created in the outlet of the pump. \\
+**The engine is force-fed oil by system pressure**. Pressure is always greatest at the oil pump outlet. Restrictions in the oil feed path lower the pressure past them depending on how much of a restriction is created and for how long. The constant squeezing of the gears / gerotors creates measurable pressure discharge but not equal to system pressure.
+===== Engine Oil Pressure, Volume and Testing =====
+==== Sub Documents ====
+  * [[techtalk:ih:oil01d|Addressing Low Oil Pressure]]
+[[techtalk:ref:oil04|Click Here]] for the "Sportster Oil Pressure (1957-Present)" page in the REF section of the Sportsterpedia". \\
+That page consists of where to test, expected oil pressure for the respective year models and a link to the page for installing a pressure gauge. \\
+On Ironheads, 80% of oil pressure is sent to the bottom end and 20% is sent to the top end according to MMI. ((2000 MMI Documents)) Ironhead engine oil pressure is measured (by the MoCo) with a pressure gauge at the oil pump. The pressure throughout the feed system will always be highest at the oil pump. \\
+The FSMs say the oil pump is non-regulatory and delivers its entire volume of oil under pressure to the motor. But that is not the entire story. \\
+**Cold oil flows slower and at higher pressure than hot oil**. During start-up of a cold (ambient temp) engine, oil is thicker, oil pressure will be higher than normal and oil circulation will be somewhat restricted to flow within the oiling path. Oil pressure should be checked when hot (operating temp) to meet the specs in the manuals. As the oil heats up it gets thinner, flows faster and pressure is lowered. \\
+**The oil path, as designed, creates variable system pressures**. The restrictions in the oil feed path (hose size, routing paths, orifice sizes, etc) manipulate oil flow and oil pressure. Each restriction in the feed path, whether chamber size, bends or orifice size, lowers the flow volume and pressure downstream of the restriction. I.E., A restrictor placed in the end of the pinion shaft will lower the amount of oil that gets passed it to the crankpin/lower end bearings but the smaller amount of oil that does flow past the restrictor flows at a faster rate. And lowering the amount of oil to the pinion shaft also sends more oil up to the rocker boxes. There will be lower pressure at the crankpin / lower end bearings than at the oil pump. There will also be lower pressure at the rocker arms then there will be at the oil pump. The OEM specs were meant to show the amount of pressure that should be present at the pump without further modifications to the feed system. Altering the OEM feed path will change the pressure at the pump to the extent of the modification.
+**Restrictions in the oil path harness and manipulate the pressure created at the pump**. Pressure is always greatest at the oil pump outlet. As the oil passes each restriction (bends, smaller passages, orifices as well as elevation), pressure will be lower from thereon depending on how much of a restriction is created and for how long. \\
+**Oil volume to the motor is dependent on RPM**. When an engine is operated at higher speeds; the volume of oil circulated through the oiling system increases, resulting in higher oil pressure throughout the feed path. As engine speed is reduced, the volume of oil pumped is also reduced, resulting in lower oil pressure throughout the feed path. \\
+==== Oil Pressure Light ====
+If the oil pressure light stays on at speeds above idling, always check the oil supply first. \\
+Then if the oil supply is normal, look inside the oil tank to determine if oil is returning to the tank from the return hose with the engine running. \\
+If oil is returning to the tank, there is some circulation and the engine may be run a short distance if necessary. \\
+If no oil is returning, shut the engine off until the trouble is located and fixed. \\
+Conditions causing the oil light to stay on; \\
+Low or diluted oil supply, \\
+Or a plugged lifter screen (86-91) under the plug between the tappets, \\
+A grounded oil signal switch wire, \\
+Faulty oil switch, \\
+Faulty or weak oil pump, \\
+Clogged feed hose (in freezing weather from ice and sludge preventing the circulation of oil). \\
+===== Year Model Specifics =====
+Refer to the drawings at the top of this page from the text below. \\
+==== 1957-1976 ====
+Oil pump feed gears send pressurized oil through a check ball mounted in the oil pump. Oil leaves the oil check and enters a hidden passage in the cam chest floor up through the cam cover internal passages to the pinion bushing / shaft. Oil is sent thru the pinion shaft to internal holes in the right flywheel to the crankpin and out to the lower end rod bearings. This is the end of oil pump pressure in the lower end. \\
+Oil is also sent past the pinion bushing thru an internal passage in the cam cover to the upper feed galley in the top of the gearcase. There is a hole in the upper cover that opens to a horizontal drilled hole in the upper right case. Oil leaves the cam cover into the upper case galley and into 2 external oil lines attached on the top of the gearcase. Both oil lines are fed by the same "oil galley" in the case. The oil lines run up and attach to the rocker boxes (front tube to front rocker box, rear tube to rear rocker box). Pressurized oil flows up each external tube into their respective rocker box. The tubes are fed "system" pressure but not as much as what is present at the oil pump. Pressure from the oil pump has been altered (lowered) by the time it gets to the rocker boxes. Oil is routed into each rocker box by "closed channels", so not the entire rocker box gets pressurized. Oil from each oil line is routed into the box, around the big bushing machined into the rocker arm bolt, thru a drilled channel to the next rocker arm bolt bushing. Oil enters a hole in each rocker arm bolt, thru that bolt and out a hole that sits under the rocker arm, thus pressurizing the rocker arm ID. Oil leaves the rocker arms thru the rocker bolt bushings and small holes underneath the "fingers" that actuate the valves. These small holes act as cooling jets onto the valves. This is the end of oil pump pressure in the top end. \\
+==== 1977-1985 ====
+Oil pump feed gerotors send pressurized oil through a check valve mounted in the oil pump. Oil leaves the oil check and enters a hidden passage in the cam chest floor up through the cam cover internal passages to the pinion bushing / shaft. Oil is sent thru the pinion shaft to internal holes in the right flywheel to the crankpin and out to the lower end rod bearings. This is the end of oil pump pressure in the lower end with the exception being 1985 models. Starting with crankcase number 785 303 002, manufactured after October 29, 1984, a spray tube was installed into the upper gearcase above the cams. The tube carries pressurized oil from the upper oil feed galley that exits out tiny holes in the tube to give the cams a constant spray of oil for extra cooling. \\
+Oil is also sent up past the pinion bushing thru an internal passage in the cam cover to the upper feed galley in the top of the gearcase. There is a hole in the upper cover that opens to a horizontal drilled hole in the upper right case. Oil leaves the cam cover into the upper case galley and into 2 external oil lines attached on the top of the gearcase. Both oil lines are fed by the same "oil galley" in the case. The oil lines run up and attach to the rocker boxes (front tube to front rocker box, rear tube to rear rocker box). Pressurized oil flows up each external tube into their respective rocker box. The tubes are fed "system" pressure but not as much as what is present at the oil pump. Pressure from the oil pump has been altered (lowered) by the time it gets to the rocker boxes. Oil is routed into each rocker box by "closed channels", so not the entire rocker box gets pressurized. Oil from each oil line is routed into the box, around the big bushing machined into the rocker arm bolt, thru a drilled channel to the next rocker arm bolt bushing. Oil enters a hole in each rocker arm bolt, thru that bolt and out a hole that sits under the rocker arm, thus pressurizing the rocker arm ID. Oil leaves the rocker arms thru the rocker bolt bushings and small holes underneath the "fingers" that actuate the valves. These small holes act as cooling jets onto the valves. This is the end of oil pump pressure in the top end. \\
+====== Oil Drainage ======
+===== Sub Documents =====
+  * [[techtalk:ih:oil01f|Drain Oil Passages Through Pics]]
+**Drain oil is not a part of the feed pressure system**. Drain oil is non-pressurized oil that exits the last orifice in the respective pressure path and eventually finds it way to the crankcase or cam chest floor awaiting to be scavenged by the oil pump. Once pressurized oil exits it's last orifice, pressure dissipates and is generally (at atmosphere) from there on. \\
+**Excess oil in the rocker boxes drains to the lower end**. Some drain oil from the rocker boxes falls to the crankcase by way of 2 drain holes in each head and cylinder while lubricating the cylinder walls, pistons, rings and main bearings. And some drain oil from the rocker boxes falls down the pushrod tubes, through channels in the lifter blocks to the gearcase compartment, lubricating the pushrods, tappets, tappet guides, tappet rollers and cam gears. \\
+**Drain oil is subject to the variable changing crankcase air pressure**. Drain oil aides in splash lube since some of that is picked up into air/oil mist and slung onto the moving parts by crankcase pressure pulses and the moving parts themselves. \\
+**There will always be an amount of oil left in the cases after shutdown**. A large portion of drain oil hits the bottom of the crankcase or cam chest and exits the motor by way of the oil pump and sent back to the oil tank during operation. During shutdown, there will be oil in the feed passages, up top in the boxes, on the flywheels and cams etc. that will fall back down to the gearcase and crankcase floors and will not be scavenged since the motor is not running. \\
+**There may also be a certain amount of oil that drains into the motor from the oil tank after shutdown**. This has been affectionately hailed as Sit Sumping on the XLForum. [[techtalk:ref:oil10#sit_sumpimg|Click Here]] to read more on sit sumping in the Sportsterpedia. There are generally 2 areas of suspect where oil can drain into a non running motor; oil check ball/check valve or the seal in the top plate of the oil pump. (1) The oil check ball/valve in the oil pump can allow oil to seep from the tank, between the gears/gerotors and up into the motor via the oil feed path. (2) Too wide of clearances or worn parts in the oil pump can allow oil to seep up into the gearcase to the crankcase. Keep in mind that oil expands when hot. So checking the oil level as soon as you shut off the motor then checking it an hour later may only show the oil shrinking when cold and may not mean the loss on the dipstick went into the motor. Checking when the oil cools down then checking hours/days/weeks later may give better longstanding results.
+====== Oil Return System (scavenge) ======
+===== Sub Documents =====
+  * [[techtalk:ih:oil01l|Oil Scavenge Passages Through Pics]]
+===== Role of Crankcase Pressure =====
+See also in the Sportsterpedia: \\
+  * [[techtalk:ih:engmech07|Ironhead Sportster Crankcase Ventilation]] \\
+  * [[techtalk:ref:engmech07|Ironhead Crankcase Pressure and Engine Breathing]]. \\
+**Positive crankcase pressure (piston downstroke) aides the scavenging ability of the pump**. Just like the feed side needs the positive push from gravity oil by way of the higher strung oil tank to operate efficiently, the return side needs a positive push of oil to their return side inlet cavity to operate efficiently and the positive push from each piston downstroke serves that purpose. The positive air pressure increases the NPSHA (Net Positive Suction Head Available) to the pump which allows the pump's suction force (vacuum), created inside the pump by the opening of the gear / gerotor teeth. \\
+[[techtalk:ref:oil21#npshr_vs_npsha|Click Here]] to read more on NPSHR vs NPSHA in the REF section of the Sportsterpedia. \\
+**Negative crankcase pressure (or vacuum from piston upstroke) makes the pump's job harder since the pump is fighting the crankcase vacuum**. Crankcase vacuum decreases NPSHA to the pump and the pump sucks oil only when oil is present in the inlet of the pump (from the gearcase drain compartment or sump port respectively). The more vacuum in the crankcase/gearcase, the less oil the pump can pick up on average. \\
+**1957-1976 engines**: \\
+**Positive crankcase pressure blows air and oil, from the crankcase, into the oil trough in the rear of the crankcase clear to the cam chest return cavity near the inlet side of the oil pump's return gears**. The crankcase, oil tank and gearcase all share the same air space so when one is pressurized, all are pressurized. Downstroke positive pressure in the gearcase serves as NPSHA to the oil pump, allowing the pump to operate efficiently. \\
+**1977-Up engines**: \\
+**Positive crankcase pressure (piston downstroke) blows oil to the exit port in the rear of the crankcase sump where it is sucked uphill to the oil pump by way of pump vacuum**. Again, downstroke positive pressure in the gearcase serves as NPSHA to the oil pump, allowing the pump to operate efficiently. \\
+===== Role of the Oil Pump - Scavenge =====
+[[techtalk:ih:oil03#ihoiling_lubrication|Click Here]] to reference the Ironhead Oil Pump section in the Sportsterpedia. \\
+The scavenge side of the pump returns oil from the bottom of the gearcase and crankcase sump to the oil tank. \\
+Oil pump pressure and crankcase pressure work together to remove oil out of the motor.
+== Oil pump suction ==
+Just as with the feed side, a vacuum is created on the inlet cavity of the return side generated by the opening of the gears (or gerotors respectively) as they rotate around to the inlet side of the pump. Pump vacuum is aided by the positive force of piston downstroke (57-76 in the gearcase, 77-85 in the crankcase) which serves as the NPSHA to the oil pump. On higher RPM, as the volume between the return gears/gerotors increase, the suction on the return path also increases (as long as there is oil at the pump's inlet to pick up). Likewise with lower RPM, the suction decreases. Too low of suction and the oil path from the crankcase loses prime and the gerotor cavities will not completely fill with oil especially on higher RPM and return oil volume will suffer. This can lead to a condition called wet sumping. \\
+[[techtalk:ref:oil10#wet_sumping|Click Here]] to read more on Wet Sumping in the REF section. \\
+== Oil pump pressure ==
+**The oil pump pressurizes the oil delivered to the return outlet cavity in the pump**. \\
+One teeth cavity of oil at a time is rotated from the inlet side to the outlet side in the pump. The closing of the gear/gerotor teeth (respectively) afterward combined with the next teeth full of oil continues squeezing (pressurizing) the outlet cavity. The faster the rotation, the higher the pressure that is created on the outlet of the pump. The slower the RPM, the lower the pressure to the outlet.
+== Role of NPSHA to the oil pump==
+NPSHA is the (Net Positive Suction Head Available) to the oil pump and is needed to aid the oil pump's return side to function properly. Basically, the pump's ability to suck oil is lessened without a force pushing oil to the pump inlet, especially at higher RPM and that positive force helps to keep enough oil at the pump's inlet to be sucked up by it's vacuum. In regard to the return side of the pump, NPSHA is created by piston downstroke (positive push on return oil to the pump's scavenge inlet). Also, the lower the RPM, the lower the NPSHA to the pump. The higher the RPM, the higher the NPSHA to the pump. [[techtalk:ref:oil21#npshr_vs_npsha|Click Here]] to read more on NPSHR vs NPSHA in the REF section of the Sportsterpedia. \\
+===== Return Oil Pressure / Volume =====
+Just like the feed side of the pump, the return side also is non-regulatory and delivers its entire volume of oil under pressure to the oil tank. Generally, pressure being exerted on the return path is not discussed in the FSM. However, return (drain) oil is not as available to the oil pump as is feed oil and availability determines (entire) volume of oil delivered to the tank. \\
+**Cold oil flows slower and at higher pressure than hot oil**. During start-up of a cold (ambient temp) engine, oil is thicker, oil pressure will be higher on the return path and oil circulation back to the tank will be somewhat restricted to flow within the return path. As the oil heats up it gets thinner, flows faster and pressure is lowered in the return path. \\
+**The return oil path, as designed, creates variable pressures between the pump and the tank**. The OEM restrictions in the oil return path (hose ID, routing paths, orifice sizes, etc) manipulate oil flow and oil pressure by a designed amount by the factory.
+**Adding additional restrictions between the pump and tank can reduce the volume of oil returning to the tank**. This is why some say that using fine mesh oil filters can leave more oil in the crankcase and lead to wetsumping.
+**Oil volume sent to the oil tank is dependent on RPM and the amount of oil available at the pump's return inlet.** When an engine is operated at higher speeds; the volume of oil circulated to the tank increases, resulting in higher oil pressure throughout the return path. As engine speed is reduced, the volume of oil pumped is also reduced, resulting in lower oil pressure throughout the return path. The return gears/gerotors are larger than the feed gears/gerotors. So there will be a point where there is less oil and more air that is passed through the return side. In reality, you'll normally see both gulps of air and gulps of oil entering the oil tank continuously interchanging.
+===== Crankcase Oil Removal =====
+=== 1957-1976 engines ===
+**The crankcase is scavenged by positive crankcase air pressure (piston downstroke and flywheel rotation**. Positive crankcase air blows oil in the crankcase up into the oil trough in the rear of the crankcase. When pistons go down, oil is pushed into the oil trough and over to a sealed compartment (or oil trap) in the gearcase near timed breather gear on top of the oil pump. When the pistons go up, there is less push on the oil as upstroke begins sucking air up into the bottom of the pistons and less oil is dropped into the oil trough. The breather gear has "windows" cut into it and timed to open when air pressure is positive (downstroke) and to close when air pressure is negative (upstroke). As the window opens, positive crankcase air and oil is drawn from the oil trap, into the side of the breather gear and blown up and out through the center of the breather gear, into the gearcase. So when the pistons go down, oil is transferred from the crankcase to the oil trap. When the pistons go up, less to no oil scavenging happens from the crankcase.
+=== 1977-1985 engines ===
+**The crankcase is scavenged by oil pump suction assisted by positive crankcase air pressure**. Positive crankcase air (from piston downstroke and flywheel rotation) pushes oil in the crankcase to the return port (pickup hole) in the rear wall of the sump and serves as the NPSHA (Net Positive Suction Head Available) to the oil pump. Oil pump return vacuum sucks oil uphill from the crankcase sump port through a vertical drilled passage between there and the rear scavenge inlet cavity (duck bill) of the oil pump. The crankcase sump outlet is below the scavenge pump inlet. So the oil has to be sucked uphill by the pump to get to the pump's inlet. When pistons go down, oil is pushed to the rear scavenge port. When the pistons go up, there is less push on the oil as upstroke begins sucking air up into the bottom of the pistons and less oil is forced to the scavenge port. This gives more oil to the pump inlet on downstroke and less oil to the pump inlet on upstroke.
+===== Gearcase Oil Removal =====
+=== 1957-1976 engines ===
+**Oil drained into the gearcase is scavenged by the oil pump**. There is a lower pocket machined into the gearcase that drops a passage through to the bottom of the case into the oil pump's scavenge inlet. There is a mesh screen above the oil pocket to keep large debris from getting down into the oil pump.
+=== 1977-1985 engines ===
+**Oil drained into the gearcase is not scavenged by the oil pump but rather it drains into the crankcase by both gravity and crankcase vacuum**. The wall between the crankcase and gearcase has a drain hole near the bottom of the gearcase floor. Outside of gravity drain, piston downstroke (vacuum) aides in pulling oil from the gearcase into the crankcase where it gets blown to the timed breather along with crankcase air and oil.
+====== Splash Lubrication ======
+See also in the Sportsterpedia: \\
+  * [[techtalk:ih:engmech07|IronHead Sportster Crankcase Ventilation]]
+  * [[techtalk:ref:engmech07|Crankcase Pressure and Engine Breathing]]
+Splash lubrication happens by way of crankcase air pulses and the spinning parts in the engine. \\
+  * **Crankcase air pressure is generated by the up and down movement of the pistons and carries splash oil to the cylinder walls, pistons, piston pins, cam bearings, cam gears and main bearings**. With little to no (piston ring) blow-by and a check valve on the breather system; crankcase pressure is essentially cycling between atmospheric and negative (pressures) as the pistons go down and back up (remember, due to the common crankpin 45 degree design, a Harley motor is a variable volume crankcase, unlike most motors) ((aswracing of the XLFORUM https://www.xlforum.net/forum/vendors/nrhs-high-performance/33374-04s-and-up-and-oil-use/page27?t=59421&page=27))
+    * The downstroke of the pistons pushes oil around the crankcase and out into the gearcase in both solid form and in a mixture of air and oil.
+    * The upstroke of the pistons creates an upward vacuum from underneath the pistons bringing some of the oil and air/oil mist to the moving parts. \\
+    * Air/oil mist is accomplished by piston upstroke (vacuum) which brings smaller particles of oil up into and mixing with the air in the crankcase. The two don't actually mix as does sugar and water. So separating them back apart is fairly easy if you add an obstacle for that 'mix' to collide into. Anything that air/oil mist hits along the way to the breather vent will separate some of the oil from the air. The last obstacle for oil separation from air on 1957-1976 engines is the oil slinger washer on the end of the generator. The last obstacle for 1977-1985 engines is the breather valve in the cam cover.
+    * Excess CC Pressure is vented out of the engine: See Crankcase Ventilation in the link above. Excess unvented crankcase pressure will simply build up inside the engine and eventually blow out gaskets / seals in the engine. The pressure (even though needed) would build high enough to be detrimental to the engine. So unusable high pressure is vented out of the engine to keep in (regulate) a certain amount of usable internal pressure.
+  * **There is no oil pump pressure in the crankcase or the gearcase/cam chest**. Static oil pump pressure has already been dissipated by the time it reaches the crankcase and the oil past the end pressure points is either considered splash or drain oil until it gets back in the tank. \\
 ===== Oil Lines to the Rockers =====
@@ Line 76: / Line 229: @@
 |  Oil line sleeves. ((photos by sc72 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/159099-rocker-box-oil-line?t=1704463))  ||
 |{{:techtalk:ih:oil:83_model_oil_line_sleeves_1_by_sc72.jpg?direct&250|}}|{{:techtalk:ih:oil:83_model_oil_line_sleeves_2_by_sc72.jpg?direct&250|}}|
-===== Rocker Box =====
-The feed to the rockers is not a large diameter passage and not a lot of oil goes to the rocker gear. ((Ferrous Head of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/92089-oil-pressure-issues?t=753175&highlight=split+rocker+box)) \\
-But if you pull the lines off with the engine running you should be getting a good steady flow out of them. \\
-====== Bottom End Oiling ======
 ===== Cam Gear Oiler (1985 models only) =====
 Starting with crankcase number 785 303 002, manufactured after October 29, 1984, a cam gear oiler was installed in the gearcase ceiling. ((HD TSB #M-899 dated November 30, 1984)) \\
  {{ pdf-bulletin:tsb0899.pdf |Click Here}} to download Service Bulletin #M-899 for more details. \\
@@ Line 99: / Line 246: @@
 |{{:techtalk:ih:engmech:1985_cam_gear_oiler_gearcase_by_iron_mike.jpg?direct&300|}}|{{:techtalk:ih:engmech:1985_cam_gear_oiler_by_insaneshane.jpg?direct&300|}}|{{:techtalk:ih:oil:cam_gear_oiler_pipe_1985_xl_pic1_by_robison_motorcycles.jpg?direct&300|}}|
-====== Transfer Valve (76 and earlier) ======
+====== Oil System Controls ======
-===== Sub Documents =====
+===== Transfer Valve (76 and earlier) =====
+==== Sub Documents ====
   * [[techtalk:ih:oil01t|Further Study of the Transfer Valve Operation and Affects of Plugging the Valve]]
   * [[techtalk:ih:oil01u|Plugging the Transfer Valve]]
+  * [[techtalk:ih:oil01v|Removing / Installing the Transfer Valve]]
 The transfer valve is not the crankcase vent (aka foo-foo valve). The crankcase vent fitting wasn't used until the 1977 model year. \\
@@ Line 164: / Line 314: @@
 {{:techtalk:ih:oil:transfer_valve_exposed_pic_2_by_needspeed.jpg?direct&500|}} ((drawing by needspeed of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/200293-oil-transfer-valve-exposed?t=2077280)) \\
-===== Removing / Installing the Transfer Valve =====
-The transfer valve is staked into place and it is steel into alloy which is always problematic. ((Ferrous Head of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/200293-oil-transfer-valve-exposed/page3?t=2077280&page=3)) \\
+===== Oil Pressure Switch =====
-If you do remove/replace the valve, make sure it is staked back in place when you finish. Use some Loctite on the threads also.\\
+==== Sub Documents ====
+  * [[techtalk:ih:oil01q|Oil Pressure Switch Removal and Installation]]
-  * You can use a hammer and punch to stake mark out of the valve slot. Be careful when hammering on your cases. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/93964-how-to-remove-the-oil-transfer-valve?t=776527))
+See also in the REF section of the Sportsterpedia: \\
-  * You can find a socket that same size as the OD of the valve. ((Dr Dick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/93964-how-to-remove-the-oil-transfer-valve?t=776527)) Lay it on the valve & give it some face hammer shots. Again, be careful. \\ Or get 2 hammers, 2 drifts, 2 guys, one for each slot. Get in rhythm so both hit at same time. \\ You don't want to brutal. It will break loose if you repeat 2&3. Be careful not to mash the valve into the case. That would re-stake the valve. Again, be careful.
-  * You can use a Snap-On Drag Link socket to remove the transfer valve. ((The Doctor71 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/200213-oil-transfer-valve?t=2077190)) You may have to grind it to fit the slots in the oil transfer valve. ((rivethog of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/93964-how-to-remove-the-oil-transfer-valve?t=776527)) \\ However Snap-On has a 15/16" wide version, stock # A17A, that fits quite well with no grinding needed. ((The Doctor71 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/93964-how-to-remove-the-oil-transfer-valve?t=776527))
-|Special tool to remove / install transfer valve. ((photo by Ferrous Head of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/200293-oil-transfer-valve-exposed/page3?t=2077280&page=3))|
-|{{:techtalk:ih:oil:transfer_valve_removal-installation_tool_by_ferrous_head.jpg?direct&300|}}|
-----
-====== Wet Sumping ======
-See article on [[techtalk:ref:oil10|Wet Sumping]] in the REF section of the Sportsterpedia
-====== Engine Pressures ======
-Different areas have different types of pressure applied and from different sources. ((bustert of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/196615-over-sized-oil-lines/page3?t=2073175&page=3)) ((Hippysmack)) \\
-**The engine has a force-fed (pressure type) oiling system incorporating oil feed and return pumps in one pump body with a check valve on the feed side.** ((86-90 HD Sportster FSM pg 3-4))
-    * The feed side of the pump forces oil to the engine to lubricate;
-      * Lower connecting rod bearings
-      * Rocker arm bushings
-      * Valve stems
-      * Valve springs
-      * Pushrods and tappets
-  * The scavenge side of the pump returns oil from the bottom of the gearcase and crankcase sump to the oil tank.
-    * **It's not unusual to get air out the oil return line (to the tank).** ((aswracing of the xlforum https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-motor-top-end/135598-crankcase-pressure?t=1468237)) \\
-It's a dry-sump system with an oil pump that's designed to keep the engine sump as dry as it can. \\
-When there's no oil to suck up, it pumps air instead into the oil tank. That's the way it's supposed to work. \\
-See also, [[techtalk:ref:oil20|Oil Tank Pressure]] in the REF section of the Sportsterpedia. \\
-===== Oil Pump and Pressure =====
-**The oil pump doesn't make pressure. All it does is create flow.** \\
-That's a bit tongue in cheek since there is a suction side and a pressure side to both gear type and gerotor type oil pumps. \\
-However, the restrictions in the engine back up what pressure the pump makes creating higher pressure. \\
-So in essence, the oil delivery system does make pressure and it can be measured with a gauge. \\
-The oil pump is non-regulated and delivers its entire volume of oil under pressure to the engine. \\
-Measurable oil pump pressure is a result of engine restrictions, as mentioned, on the pressure side of the pump. \\
-(i.e. lines, routing, holes and galley sizes) \\
-**Oil is gravity fed from the oil tank to the oil pump.** \\
-In essence, the oil tank is mounted above the oil pump and the feed line runs down to the pump. \\
-**However, there is also a vacuum on both the feed and return inlets that does most of the work bringing oil into the pump.** \\
-It's an added part of the system once the pump starts turning (in addition to and with more force than gravity). \\
-As the volume between the gears / gerotors increases (with engine RPM), the suction from them also increases. ((shanneba of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/196615-over-sized-oil-lines/page3?t=2073175&page=3)) \\
-Likewise, as the RPM lowers, the suction decreases. \\
-The opening action between the gears / gerotors as the cavities rotate apart creates a backdraft (or vacuum) on the incoming oil supply line. \\
-The closing action between the gears / gerotors as the cavities rotate together creates pressure that pushes oil out the discharge side of the pump. ((Hippysmack of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/196615-over-sized-oil-lines/page3?t=2073175&page=3)) \\
-===== Expected Engine Oil Pressure (1957-1985) =====
-See also [[techtalk:ref:oil04#sportster_oil_pressure_57_to_present|Sportster Oil Pressure (57 to Present)]] in the REF section of the Sportsterpedia. \\
-On ironheads, 80% of oil pressure is sent to the bottom end and 20% is sent to the top end. ((2000 MMI Documents)) \\
-The oil pump is non-regulatory and delivers its entire volume of oil under pressure to the oil filter mount. \\
-When an engine is cold, the engine oil will be more viscous (ie., thicker). \\
-During start-up of a cold engine, oil pressure will be higher than normal and oil circulation will be somewhat restricted within the oiling system. \\
-As the engine wams to normal operating temperature, the engine oil will warm up also and become less viscous - oil pressure will decrease.
-When an engine is operated at high speeds; \\
-The volume of oil circulated through the oiling system increases, resulting in higher oil pressure. \\
-As engine speed is reduced, the volume of oil pumped is also reduced, resulting in lower oil pressure. \\
-**Ironhead engine oil pressure was measured (by the MoCo) with a pressure gauge at the oil pump**. \\
-See expected oil pump pressures below (per FSM's): \\
-**Gauge mounted at oil pump**: \\
-As checked with hot oil and a gauge at the oil pressure switch location at the oil pump. \\
-The oil pressure switch has to be removed for the gauge to be installed. \\
-**1957-1969**: ((1959-1969 HD FSM pgs 3A-11, 3A-15)) \\
-Minimum: 3-7 psi (idle, with spark retarded) \\
-Normal riding conditions: 10-14 psi (6 psi at 20 mph) \\
-**1970-1978**: ((HD 70-78 FSM pgs 3-1, 3-5)) \\
-Minimum: 3-7 psi (idle) \\
-Maximum: 15 psi (60 mph in high gear) \\
-Normal riding conditions: 4-15 psi
-**1979-1985**: ((1979-1985 HD FSM pgs 3-1, 3-10)) \\
-Minimum: 4-7 psi (idle) \\
-Maximum: 10-20 psi (3500 rpm) \\
-Normal riding conditions: 4-15 psi \\
-**Note**: On a cold startup, expect pressure to reach ~60 psi ((IronMick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/134952-where-how-to-mount-custom-oil-pressure-gauge?t=1456449)) \\
-===== Low Oil Pressure =====
-The oil pressure light can fluctuate on and off for many reasons. \\
-It doesn't necessarily mean you have low oil pressure (or flow) to the engine. \\
-However, it does warrant immediate concern and diagnosis. \\
-In fact, at idle, the oil pump check valve is barely opened past it's cracking pressure. Low revs at idle can cause the oil light to flicker off and on. \\
-A flickering light could be a loose or grounding switch wire, bad switch, oil too thin (viscosity breakdown), clearances in the oil pump worn and others. \\
-Don't assume the light or switch is bad. The job of the oil light and switch is to alert you of an oiling problem before it becomes a bigger problem. \\
-**First, check for oil return in the tank**. \\ General rule of thumb is, if you have oil returning from the motor, then you also have oil feeding the motor. \\ But don't just take that for granted either. \\  With the motor running, remove the oil cap and look inside the tank for oil movement as coming from the return line. \\ __If you're sure oil is not returning to the oil tank__, immediately shut off the engine and diagnose why. \\ Don't automatically assume it's a bad pump. There are many things that can cause this. Hoses and connections could need attention instead.
-**Check hoses and connections**: \\
-    * Check the return hose for kinks / cracks / damage and make sure the hose is tight with no leaks at all connections. \\ The inner lining of old or rotten hoses has also been known to collapse and block oil flow.
-    * Check the feed hose from the tank to the pump. \\ Visually inspect it for kinks / cracks / damage and make sure the hose is tight with no leaks at all connections. \\ A loose connection may not leak oil but may induce air into the feed line lowering oil flow into the pump from the tank.
-    * Verify the feed hose from the tank to pump will voluntarily flow oil out the lower end of the hose (pump inlet side). \\ Remove the hose at the pump only. \\ If no oil flows from gravity alone (and the tank has enough oil), verify the tank vent line is not pinched or stopped up.
-    * Verify that the oil tank vent is free and clear from blockage (allowing pressure to equalize in the tank). \\ Pull the vent line at the engine or cam chest respectively of year model. \\ Induce air into the line and check that the air is coming into the tank. \\ If no air goes through the vent to the tank or if pin holes in the line are found, replace the vent line. \\ Pin holes can both leak air out and leak air into the hose compounding crankcase pressure in the bottom end.
-**Check for oil flow from the pump both return and feed**:
-    * Check for flow out the return fitting at the pump. \\ Pull the return line from the engine / pump respectively. \\ Place a spare hose on the return fitting and to a catch can. Then roll the engine over by hand and verify that oil will come out of the fitting. \\ If no oil at all comes out, then pull the pump and check for internal damage / blockage. \\ There probably won't be lot of flow, just verify the gears/gerotors are turning and moving oil.
-    * Check for flow out the feed fitting at the pump. \\ Pull the oil switch from the pump. \\ Place a spare hose on the pump fitting and to a catch can. Then roll the engine over by hand and verify that oil will come out of the fitting. \\ If no oil at all comes out, then pull the pump and check for internal damage / blockage. \\ There probably won't be lot of flow, just verify the gears/gerotors are turning and moving oil.
-**Verify that the oil pressure light is functioning properly**: \\
-    * Check for a loose or faulty connection at the oil pressure switch. \\ The wire connection at the oil pressure switch has to be tight so vibration won't cause intermittent signal loss to the oil light.
-    * Inspect the signal wire between the light and the pressure switch for kinks, cuts or faults.
-      * Make sure it's not grounding out on nearby metal parts (especially melted PVC jackets under wire ties).
-      * Run a continuity test on the entire length of wire with a multi-meter.
-      * Repair or replace the wire as needed.
-    * Verify that the light is not faulty or burnt out.
-      * Disconnect the wire at the oil pressure switch.
-      * Run a jumper wire off the (+) side of the battery to the end of the oil light wire.
-      * Verify it lights up and then bump the light by hand to verify vibration doesn't affect it.
-**Verify that the oil pressure switch is working properly**: \\
-The oil pressure switch is a spring loaded diaphragm. \\ With insufficient pressure pushing against the spring mechanism, the switch is normally grounded. \\ The switch grounds the circuit to the engine to make the light come on. \\ With adequate oil pressure against the spring, the circuit contact is broken which turns off the oil light. \\ [[techtalk:ih:oil01#oil_pressure_switch|See below for the functions and testing of the oil pressure switch]].
-**Check the oil pressure against the specs in the service manual** \\
-  * [[techtalk:ref:oil04|Click Here]] to view the page in the REF section on expected oil pressure for 1957-up Sportsters. \\ For Ironheads, testing at the rocker boxes will give you lower pressure on the gauge and cannot be used for overall oiling system health. \\ Be sure to check pressure at the oil pump, not the rocker boxes.
-  * The pressure reading is directly tied to the flow rate. More flow = more gauge pressure, Less flow = less gauge pressure.
-  * If you have 6 PSI on cold start at the heads, you have more than that at the oil pump.
-  * [[techtalk:ref:oil15|Click Here]] to view "Installing a Pressure Gauge" in the REF section of the Sportsterpedia.
-**A faulty oil pump check ball / valve spring in the pump may not turn off the oil light**: \\
-  * On 1957-1976 models, verify correct oil check ball spring pressure (1957-1976):
-    * If the check valve spring pressure is changed with a stiffer spring or if the spring has been stretched (extended), \\ The oil pump may not make sufficient oil pressure to overcome the spring pressure at warm idle. \\ The oil light may stay on until higher RPM raises oil pressure enough to overcome the spring pressure.
-  * On 1977-1985 models, the restricted orifice in the check valve in the pump creates back pressure to actuate the oil pressure switch. \\
-    * If the check valve is stuck in the open position;
-      * The oil still has to travel through the restricted orifice in the check which creates backpressure to actuate the pressure switch → oil light.
-    * If the check valve was stuck in the closed position;
-      * Pressure would still build up inside the oil pump and actuate the oil pressure switch and then the oil light. \\ This would seem like everything is fine with the engine running and the light off. \\ However, with the check closed, no oil would enter the engine.
-      * To check for a stuck closed check valve, remove oil the pump and cover, push a small screwdriver or suitable metal rod into check valve opening. \\ The valve should be closed and the rod should push back on the internal spring with ease. \\ If it is stiff, remove the check from the pump body and then remove it's O-ring seal. \\ Soak it in solvent while pushing in and working the valve open and closed until it is easy to move with the rod. \\ If it won't spring back, replace the check valve.
-    * [[techtalk:ih:oil01#oil_pump_check_valve|See more about the operation of the check valve below]].
-**Check for other possible causes of low oil pressure**: \\
-  * If the tank is empty, obviously oil pressure will be low. Do not check oil level with a cold engine (operating temp only)
-  * The oil filter (if applicable) could be restricted or plugged up.
-  * There has been occasions where silicon (placed on the oil pump gasket during installation) had made it's way into orifices inside the engine. \\ You can blow compressed air thru oil inlet and outlets in the engine. \\ You can also blow out the oil lines.
-  * No oil to the top end (1957-1976):
-    * Make sure the rubber grommets on each end of the stock rocker feed lines are not partially plugging the ends of the rocker feed lines. \\ Then remove the allen-hex rocker spindle plug from the front exhaust rocker spindle, at the right-hand side of the rocker box. \\ Oil should come out there if you have flow with the engine running. ((Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/98031-suggestions-on-lack-of-oil-to-top-end?t=831522))
-    * You can loosen or remove the 1/8" NPT pipe plug from the right side, front corner of each rocker cover. \\ With the engine at idle, you should get a small amount of oil plopping out (not shooting out like a fire hose). ((IronMick of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/150025-losing-oil-pressure-when-warm/page3?t=1625333&page=3))
-    * You can also use the same 1/8" plug hole to install a barb and clear hose to visually inspect for oil flow. \\ {{:techtalk:ih:oil:checking_for_oil_flow_at_the_rocker_box_by_chevelle.jpg?direct&300|}} ((photo by chevelle of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/150025-losing-oil-pressure-when-warm/page2?t=1625333&page=2))
-    * Check the pinion shaft to bushing clearance to the specs in the FSM. \\ If the fit is overly loose, this condition will not allow oil to be transferred up the lines at low speed. \\ Oil will just be bled out into the cam chest until RPM sends and over-runs more oil than can be spilled at the bushing.
-      * If the fit is out of spec, you'll need to replace the bushing. ((Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/98031-suggestions-on-lack-of-oil-to-top-end?t=831522&highlight=crankcase+pressure))
-      * Then line ream it using a special reamer through an old right-hand crankcase half to use to guide to get it in square.
-     * On 76< motors, it's best to eliminate that possibility before spending time and money yanking the engine out of the frame and inspecting the oil pump. \\ (and before spending money getting a new pinion bushing reamed with the special tooling etc.) ((Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/98031-suggestions-on-lack-of-oil-to-top-end/page2?t=831522&highlight=crankcase+pressure&page=2))
-  * The oil pump could be weak or malfunctioning.
-  * 76< pumps:
-    * If the pump shaft seal is blown, then the scavenge pump will continue to function because the pump pressure is higher than scavenge pressure. ((XLFREAK of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/98031-suggestions-on-lack-of-oil-to-top-end/page4?t=831522&highlight=crankcase+pressure&page=4)) \\ So oil will flow from your pump down the shaft into the scavenge pump and goes back to the tank from there. \\ It's possible the pump got some trash in it and got scarred and now just doesn't pump very well. \\ It's a nasty job getting the thing off, made doubly nasty if you don't find anything wrong. \\ If you have an oil flow problem from the pump, you can either rebuild it or put a new one on just to make sure that this is not the problem. \\ If it isn't the pump, then start looking for leaks.
-**Remove and inspect the oil pump**. \\
-The oil pump supplies pressurized oil into a hole in the cam cover. \\
-That pressurized oil is forced up the lines (between the cylinders) to the rocker box by the oil pump. \\
-That is the vertical end of responsibility (pressure wise) for the oil pump. \\
-Before the oil reaches the rocker lines, it splits off to a hole through the pinion shaft (to get to the rod bearings). \\
-This is the horizontal end of responsibility (pressure wise) for the oil pump. \\
-With this pressure comes a certain amount of oil flow from the oil pump. \\
-With a weak oil pump, there will be less pressure forced up the oil lines. \\
-This will result in less oil reaching the rockers. \\
-But, not necessarily less oil reaching the rod bearings (depending on degree of pump pressure reduction). \\
-How much oil loss to the rockers is acceptable is yet to be determined. \\
-However, the MoCo had to have accounted for a certain amount of pressure loss from the pump during the engineering phase. \\
-But, the service limit for oil pressure was not detailed in the FSM. \\
-===== Checking Oil Pressure =====
-See also [[techtalk:ref:oil15|Installing an Oil Pressure Gauge]] in the Sportsterpedia. \\
-When checking oil pressure, it's important to note that you are not testing pressure at a dead stop standpoint. \\
-The oil is flowing into the engine at the same time you are testing from a still test site. \\
-Likewise, the resulting pressure reading is a reflection of residual pressure while that pressure is being manipulated. \\
-(by oil flow as well as the current viscosity) \\
-According to the MoCo (FSMs), the oil pump is the prime testing point of oil pressure to the engine. \\
-The procedure is to take the oil pressure gauge off and install an oil gauge there. \\
-This works if you have verified that you do have oil flow to the engine and just want to check the pressure at the pump. \\
-This takes the oil pressure switch as well as the oil light out of line. \\
-However a tee can be added inline for a dedicated gauge. \\
-You can either mount a permanent gauge to the tap or plug it off until needed. \\
-This will keep the switch and the oil light inline and working if you need it. \\
-{{:techtalk:ih:oil:oil_pressure_gauge_1_by_dieselox4.jpg?direct&300|}} ((photo by Dieselox4 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/134952-where-how-to-mount-custom-oil-pressure-gauge?t=1456449)) {{:techtalk:ih:oil:oil_pressure_gauge_2_by_dieselox4.jpg?direct&300|}} ((photo by Dieselox4 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/134952-where-how-to-mount-custom-oil-pressure-gauge?t=1456449))
-===== Crankcase Pressure =====
-See also [[techtalk:ref:engmech07|IH Crankcase Pressure and Engine Breathing]] in the REF section of the Sportsterpedia. \\
-Crankcase air pressure is mainly generated by the up and down movement of the pistons. \\
-The downstroke of the piston causes the volume underneath the pistons to decrease which puts pressure on the oil in the crankcase / sump respectively. \\
-This pressure is multi use; \\
-  * It helps to push sump oil up and out the scavenge passage to the return side of the oil pump.
-  * It also initiates the splash and mist process as the compressed air above the oil is ready to spring up when the piston rises.
-Then the upstroke of the piston creates an upward vacuum bringing some of the oil from the sump with it. \\
-With little to no (piston ring) blow-by and a check valve on the breather system; \\
-Crankcase pressure is essentially cycling between atmospheric and negative (pressures) as the pistons go down and back up. \\
-(remember, due to the common crankpin 45 degree design, a Harley motor is a variable volume crankcase, unlike most motors) ((aswracing of the XLFORUM https://www.xlforum.net/forum/vendors/nrhs-high-performance/33374-04s-and-up-and-oil-use/page27?t=59421&page=27)) \\
-This creates splash oil which is bounced about in the crankcase. \\
-This also creates an air / oil mix when tiny particles intertwine with the oil in suspension. \\
-The two don't actually mix as does sugar and water. \\
-So separating them back apart is fairly easy if you add an obstacle for that 'mix' to collide into. \\
-Collision is the means in which most air / oil is separated. Everything the air / oil mist runs into on the way to the vent separates oil from air. \\
-On all models, the oil tank also doubles as an air / oil separator. \\
-On 57-E84 models, the final obstacle for separation is the oil slinger near the breather vent. \\
-On L84-85 models, the final separation obstacle is the breather valve in the cam cover.
-The piston motions create a pulsating blast of air pressure (push pull condition as each piston rises and falls). \\
-Static oil pump pressure has already been dissipated by the time it reaches the crankcase. \\
-(although it takes static oil pressure to get the oil from the pump to the crankcase thru restrictions in the feed path) \\
-Likewise, crankcase (CC) pressure will have a constant change in velocity. \\
-Oil in the crankcase adds resistance to the air pressure generated (raising the pressure). \\
-Gravity oil drains from rocker boxes; \\
-Returns oil to the crankcase via the drain ports in the heads / cylinders and to the gearcase via the pushrod tubes. \\
-=== Some CC Pressure is needed ===
-Some of the oil is picked up by the piston upstroke and mixed with the air pressure in the form of mist. \\
-The mist and splash oil lubricates crankcase components. \\
-And they are also carried into the gearcase compartment to help lubricate the cams and pinion / oil pump gears. \\
-Splash and gravity oil from the connecting rods, crankshaft, rocker boxes and head/cylinder drainage holes serve to lubricate;
-  * Cylinder walls
-  * Pistons, piston pins
-  * Cam gears and bushings
-  * Main bearings
-=== Excess CC Pressure is vented out of the engine ===
-See also [[techtalk:evo:engmech07|Crankcase Ventilation]] in the Sportsterpedia. \\
-Unvented crankcase pressure will simply build up inside the engine and eventually blow out geaskets / seals in the engine. \\
-The pressure (even though needed) would build high enough to be detrimental to the engine. \\
-So unusable high pressure is vented out of the engine to keep in (regulate) a certain amount of usable internal pressure. \\
-====== Oil Pressure Switch ======
-See also in the Sportsterpedia: \\
  * [[techtalk:ref:oil19|Homemade Oil Pressure Light]] in case you don't have one. \\
  * [[techtalk:ref:svcproc30#testing_the_oil_pressure_switch|Testing the Oil Pressure Switch]] \\
-{{ :techtalk:evo:oil:oil_pressure_switch_threads_by_hippysmack.png?direct&300|}} ((drawing by Hippysmack)) \\
 The oil pressure switch (for the oil light) is a pressure actuated diaphragm type on / off switch basically. \\
@@ Line 433: / Line 342: @@
 However, hot idle oil pressure will vary from 3-7 PSI. \\
 __So, at idle, the oil pump check valve is barely opened past it's cracking pressure__ (not to it's end of travel). \\
-**In the Case of a Defective Oil Pump Switch**: \\
-This switch opens and closes the contacts to the oil pressure light. \\
-The oil light is important to have since if it is not working, it can be assumed that you have little to none oil flow to the engine. \\
-If the pressure switch doesn't operate the light it should be checked for proper operation or replaced. \\
-For the $30 or whatever you save by not buying the switch, it's just not worth it to not have the low engine pressure idiot light working. ((billeuze of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/121221-76-ironhead-oil-line-help-with-photos/page3?t=1185646&page=3)) \\
-If your motor is ready to run and you need to test it then you can connect a piece of clear hose so you can see oil in it. \\ Don't plug the end till you've primed the pump (with ignition off kick it over a few times until oil comes out the clear pipe where the pressure switch lives). \\
-Replace a defective switch as soon as possible. \\
-  * If the pressure switch is stuck in the closed position; \\ The circuit stays grounded with the engine running and the light stays on. \\ Hardened oil goop around the end of the switch can possibly block oil pressure from opening the switch.
-  * If the pressure switch is stuck in the open position; \\ The circuit will stay open with the engine running or not. \\ The light will not come on during startup or alert you of low oil pressure during engine operation.
 **Oil Pressure Switch Pics** \\
@@ Line 450: / Line 348: @@
 |{{:techtalk:ih:oil:oil_pressure_switch_3_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ih:oil:oil_pressure_switch_4_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ih:oil:oil_pressure_switch_5_by_hippysmack.jpg?direct&300|}}|
-====== Oil Pump Check Valve ======
+===== Oil Pump Check Valve =====
-**The oil pump check valve plays a role in the operation of the  oil pressure switch**. \\
+==== Sub Documents ====
+  * [[techtalk:ih:oil01r|Oil Check Valve Replacement Options]]
+See also in the Sportsterpedia; \\
+[[techtalk:ih:oil03b#check_valve_dims|Click Here]] to view Check Valve Dims. \\
+**The oil pump check valve plays a role in the operation of the  oil pressure switch**. \\
+It adds additional restriction in the feed path which raises the oil pressure in the chamber feeding the switch. \\
 {{:techtalk:ih:oil:77-85_oil_check_valve_1_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) {{:techtalk:ih:oil:77-85_oil_pump_check_valve_pocket_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) \\
-The check valve is not a pass through but instead a cartridge type one way check valve operated by a spring loaded cup against a seat pressing at 4-6 PSI. \\
+The check valve is not a pass through but instead a cartridge type one way check valve operated by a spring loaded cup against a seat pressing at 4-6 PSI. Oil pressure enters the center of the check valve, lifts the cup against its spring and exits the check valve by pushing around and past the cup and into the engine. At a point, the cup will float off it's seat up against the spring towards the end of it's travel. \\
-Oil pressure enters the center of the check valve, lifts the cup against its spring and exits the check valve by pushing around and past the cup and into the engine. \\
-At a point, the cup will float off it's seat up against the spring towards the end of it's travel. \\
 According to the FSM, the check valve has two main functions; \\
@@ Line 463: / Line 365: @@
 It also acts as a restriction to activate the oil pressure switch.\\
-Without the check valve, the pressure would not build up as much in the 'pocket' in the pump (see drawing above). \\
+Without the check valve, the pressure would not build up as much in the 'pocket' in the pump (see drawing above). It would free flow into the crankcase and disperse. With the check valve installed and the oil having to find it's way around the cup, pressure builds behind it in the pocket. This back pressure builds inside the pump and pushes the pressure switch contacts open, shutting off the oil light. \\
-It would free flow into the crankcase and disperse. \\
-With the check valve installed and the oil having to find it's way around the cup, pressure builds behind it in the pocket. \\
-This back pressure builds inside the pump and pushes the pressure switch contacts open, shutting off the oil light. \\
-The check valve spring does not control the amount of oil that enters the engine (unless it's stuck closed). \\
+The check valve spring does not control the amount of oil that enters the engine (unless it's stuck closed). The flow goes past the check no matter what. The spring pressure is very light. It regulates (creates and manages) the oil pressure in the pocket next to the switch before it enters the engine. That pocket is protected for one reason (to operate the oil switch, therefore the oil light). If you are not running an oil light, there is no reason to be concerned with the check valve (in regards to a running engine). You could remove the light and the check and it would not affect the oil flow thru the engine. The positive displacement oil pump will still deliver oil. \\
-The flow goes past the check no matter what. The spring pressure is very light. \\
-It regulates (creates and manages) the oil pressure in the pocket next to the switch before it enters the engine. \\
-That pocket is protected for one reason (to operate the oil switch, therefore the oil light). \\
-If you are not running an oil light, there is no reason to be concerned with the check valve (in regards to a running engine). \\
-You could remove the light and the check and it would not affect the oil flow thru the engine. \\
-The positive displacement oil pump will still deliver oil. \\
 The check/switch/light is a safety precaution to let you see the light and warn you that the pressure in the pocket is low. \\
-In theory and design, if the pressure in the pocket is low, oil flow would also be low. \\
+In theory and design, if the pressure in the pocket is low, oil flow would also be low. In practice, there are too many variables on a worn engine,pump, check, switch etc. to keep theory and design true all the time. \\
-In practice, there are too many variables on a worn engine,pump, check, switch etc. to keep theory and design true all the time. \\
-The cup will stay off it's seat and open as long as there is sufficient oil pressure pushing against its spring. \\
+The cup will stay off it's seat and open as long as there is sufficient oil pressure pushing against its spring. This spring actuates the 4-6 PSI pressure that the pump must overcome. If there is not enough oil pressure coming from the pump to keep the check valve cup completely or partially off it's seat; The back pressure from the spring will push the cup toward it's seat, or closed position, equal to the amount of minimum pressure loss from the pump. Thinner (hotter) oil flows faster and builds less pressure. \\
-This spring actuates the 4-6 PSI pressure that the pump must overcome. \\
-If there is not enough oil pressure coming from the pump to keep the check valve cup completely or partially off it's seat; \\
-The back pressure from the spring will push the cup toward it's seat, or closed position, equal to the amount of minimum pressure loss from the pump. \\
-Thinner (hotter) oil flows faster and builds less pressure. \\
-When the oil thins out, the oil pressure will still try to push past the cup. \\
+When the oil thins out, the oil pressure will still try to push past the cup. At a point, the pressure from the pump may not be sufficient to completely float the cup off it's seat. So, the cup will turn sideways a bit only allowing oil to pass it on one side. \\
-At a point, the pressure from the pump may not be sufficient to completely float the cup off it's seat. \\
-So, the cup will turn sideways a bit only allowing oil to pass it on one side. \\
 {{:techtalk:ih:oil:77-85_oil_check_valve_drawing_by_hippysmack.jpg?direct&500|}}
-This reduction in pressure is also sensed by the oil pressure switch. \\
+This reduction in pressure is also sensed by the oil pressure switch. When the pressure drops, the diaphragm eases back toward the closed position. If the pressure is low enough, the contacts will close or partially make contact while closing or intermittently opening and closing. The oil light will come on or flicker depending on the action of the contacts. \\
-When the pressure drops, the diaphragm eases back toward the closed position. \\
-If the pressure is low enough, the contacts will close or partially make contact while closing or intermittently opening and closing. \\
-The oil light will come on or flicker depending on the action of the contacts. \\
-The pressure switch requires no back pressure from the engine to stay open.\\
+The pressure switch requires no back pressure from the engine to stay open. It opens solely from the pressure generated from the oil pump with the assistance of the check valve to hold some of that pressure in the pump. \\
-It opens solely from the pressure generated from the oil pump with the assistance of the check valve to hold some of that pressure in the pump. \\
-So, it is possible but not likely to have a stuck closed check valve with no oil light on. \\
-====== Oil Tank Pressure ======
+===== Rear Chain Oiler (1957-1976) =====
-See the full article, [[techtalk:ref:oil20|Oil Tank Pressure]], in the REF section of the Sportsterpedia. \\
+==== Sub Documents ====
-There should not be any noticeable pressure in the oil tank. \\
+  * [[techtalk:ih:oil01x|Individual Chain Oiler Parts and Pics]]
+  * [[techtalk:ih:oil01y|Chain Oiler Cleaning and Adjustment]]
+  * [[techtalk:ih:oil01z|Blocking Off the Chain Oiler]]
-**During normal operation**; \\
+The chain oiler is not part of the feed pressure system. It is tapped off the return oil system and is a designed leak to keep the chain from rusting up. There is a factory adjusting screw to control the amount of oil it gives. Return oil is tapped into to provide a drip for the chain. Due to it's nature, there will always be an oil leak from it. If you don't want the leak, you can try and tighten the adjusting screw. But chances are the screw or fitting itself has previously been tightened too much leading to an eternal leak. \\
-With the tank cap / dipstick removed, tank pressure is vented to atmosphere from the top of the tank. \\
-With the tank cap / dipstick installed, tank pressure is vented to the cam chest. \\
-**During shutdown**; \\
+**Location**: \\
-The oil tank vent is connected to the cam chest and the cam chest is vented out the breather valve in the cam cover. \\
+The chain oiler fitting is either located behind the sprocket cover or at the oil tank respectively of year model and sometimes which tank you use. \\
-So if you have pressure in your oil tank and the vent to the cam chest is not blocked then the cam chest is also pressurized. \\
+  * **1954-1966 KH, XL and XLH** used a (63607-53) NPT x compression tubing x SAE threaded regulating fitting.
-If the cam chest is holding pressure, then your breather valve can not be venting properly. \\
+  * **1958-1969 XLCH** used a (63601-54) NPT x SAE x 1/4" hose bibb regulating fitting mounted to the oil tank.
+    * (63611-53), chain oiler upper hose bracket mounts to the top of the case under the (R) motor mount bolt.
+    * (63612-53), chain oiler lower hose bracket mounts to the rear motor mount front right bolt to the case.
+  * **1967-E1972 XLH and 1970-E1972 XLCH** used a (63595-67) hex body flared connection regulating fitting with a mounting tab to the top of the motor behind the rear sprocket.
+  * **L1972-1976 XLH and XLCH** used a (63595-72) updated hex body flared connection regulating fitting with a mounting tab to the top of the motor behind the rear sprocket.
-Bottom line is that if the vent system is working properly, you shouldn't have excessive pressure build up in the oil tank. ((Deimus of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-suspension-frame-forks-handlebars-fuel-tank-oil-tank-fenders/40457-whoa-oil-tank-vomits-oil?t=87313)) \\
+**Installed Pics**: \\
-====== Changing / Draining Engine Oil ======
+Below is a L1962-1965 XLCH "horseshoe" oil tank with an explanation of how the chain oiler gets it's oil. \\
+The blue line is the oil level. The red line is a tube inside the tank. The bottom of that tube feeds the lower (chain oiler) fitting. \\
+The top of the tube is open and above the oil level. So, nothing drains out of the bottom fitting if you open it. \\
+Note the open top of red tube is directly below the return fitting. \\
+When the bike is running, return oil spills into the red tube to supply the chain oiler fitting installed in the lower port. \\
+This feeds chain only when the engine is running and doesn't leak when the bike is shut off. \\
+{{:techtalk:ih:oil:l62-65_ch_oem_oil_tank_by_ted_b.jpg?direct&300|}} ((photo by Ted B of the XLFORUM, labeled by Dr Dick https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/176586-mystery-fitting-on-oil-tank-what-is-it?t=1894782)) \\
-====== Oil Tank Capacity ======
+|  Chain Oiler Piping on 74 XLCH ((photo by K Beggs of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/138839-thoughts-opinions-ideas-on-this-oil-line?t=1506737))  |
-|1970-1978|3 quarts|
+|{{:techtalk:ih:oil:1974_xlh_chain_oiler_piping_by_k_beggs.jpg?direct&300|}} |
-|1979-1981|4 quarts|
-|1982-1985|3 quarts|
-====== Oil Filter ======
-|1970-E1980|Drop in element (63840)|
-|L1980-E1984|Spin-on|
-|L1984-1985|Spin-on|
 ====== Oil Filter Mount ======
 See also [[techtalk:ref:oil13|Remote Oil Filters]] in the REF section of the Sportsterpedia. \\
+\\
 **----- 1957-1978 XL - XLH Models -----**
 XLCH models did not have an oil filter. \\
-XL / XLH models have an oil filter mounted inside the oil tank. \\
+XL / XLH models have a "drop in" oil filter mounted inside the oil tank. \\
 |  76 XLH filter in tank. ((photo by 4th of July of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/74140-oil-change-101-%C2%96-engine-and-transmission-oil-change-pics/page10?t=518192&highlight=oil+bag+filter&page=10))  ||'Drop in' oil filter. ((photo by Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/74140-oil-change-101-%C2%96-engine-and-transmission-oil-change-pics?t=518192&highlight=oil+bag+filter))|
@@ Line 548: / Line 433: @@
 **----- 1980-1981 Models -----**
-The oil filter was relocated on 1980 and up models and they were fitted with an external oil filter. \\
+The oil filter was relocated on 1980 and up models and they were fitted with an external "spin-on" oil filter. \\
 The filter mount is located on a bracket between the engine and the oil tank. \\
 It's under the seat in a awkward place to work with. ((MXHD55U of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/192060-my-completely-original-1980-ironhead/page3?t=2053271&highlight=motor+mount+oil+filter&page=3)) \\
@@ Line 597: / Line 482: @@
 **Dims**: \\
 |{{:techtalk:ih:oil:79-85_oil_filter_adapter_1_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ih:oil:79-85_oil_filter_adapter_2_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ih:oil:79-85_oil_filter_adapter_3_by_hippysmack.jpg?direct&300|}}|
-====== Crankcase Oil Strainer (1957-1976) ======
-  * If you've split the cases and the screen is in good shape, you don't have to take it out. Hit it with some compressed air and see if it needs replacing. ((BuckIRyder of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/61381-crankcase-oil-strainer?t=357456&highlight=xlch+strainer))
-{{:techtalk:ih:engmech:crankcase_oil_strainer_by_happy_bob.jpg?direct&400|}} ((photo by Happy Bob of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/61381-crankcase-oil-strainer?t=357456&highlight=xlch+strainer)) {{:techtalk:ih:engmech:oil_screen_on_75_model_by_betasom.jpg?direct&400|}} ((photo by betasom of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/173015-oil-metal-filter-remove?t=1856189)) \\ The strainer is held in place by this pin. It is staked into place with the two horizontal lines radiating from the it. To remove strainer, you must first remove the pin. Tear the screen from the strainer and place pliers on the pin inside (the now destroyed strainer) and wiggle the pin out. Strainers and strainer gaskets are available for replacement. ((Hillclimb68xlch of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/61381-crankcase-oil-strainer?t=357456&highlight=xlch+strainer))
 \\
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