Differences

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--- techtalk:evo:oil01 [2024/02/05 01:02]
hippysmack [Role of the Oil Tank]
+++ techtalk:evo:oil01 [2024/02/21 18:53] (current)
hippysmack [Engine Oil Pressure and Testing]
@@ Line 26: / Line 26: @@
   * [[techtalk:evo:oil01a|Feed Oil Passages Through Pics]]
+===== Role of the Oil Tank =====
+[[techtalk:evo:oil04#evooiling_lubrication|Click Here]] to reference the Evo 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.
+**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. \\
 ===== Role of the Oil Pump =====
@@ Line 46: / Line 63: @@
 **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 gerotor 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. \\
-**Restrictions in the oil path harness the pressure created at the pump**. 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 gerotors creates measurable pressure discharge but not equal to system pressure. The oil path, as designed, creates system pressure. The restrictions in the oil feed path (hose size, routing paths, orifice sizes) manipulate oil flow and oil pressure (which is normally measured with a PSI gauge). \\
 **The engine is force-fed oil by system pressure** to the oil filter pad where a check valve (1986-1990) or check ball (1991-up) is opened at 4-6 PSI. The discharge side of the pump forces oil to the engine to lubricate Lifters, Rocker arm bushings Valve stems, Valve springs, Pushrods and Lower connecting rod bearings. \\
@@ Line 55: / Line 70: @@
 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 Evo engines, 20% of oil pressure is sent to the bottom end and 80% is sent to the top end. ((2000 MMI Documents)) The FSMs say oil pump is non-regulatory and delivers its entire volume of oil under pressure to the oil filter mount. But that is not the entire story. Cold oil flows slow and pressure builds while hot oil flows faster and pressure lowers. So the pump will not deliver the same amount of oil when cold rather than when hot. 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.
+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. \\
-As the engine wams to normal operating temperature, the engine oil will warm up also and become less viscous - oil pressure will decrease. \\
-Also,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. \\
+**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 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 pump capabilities and 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 =====
@@ Line 70: / Line 104: @@
 ==== 1992-2003 engines ====
-Oil pump feed gerotors send pressurized oil up through a cavity in the filter housing via one external hose to the oil filter pad. \\ The oil leaves the filter and is routed past a check ball (opening at 4-6 PSI) in the filter adapter and through a passage in the upper case's oil feed galley. 1992-up engines do not use a oil pressure bypass system. The high pressure oil bypass was deleted with the addition of a cam squirter hole drilled from the upper cam case through to the upper feed galley. A (.060") hole from the upper feed galley sprays oil onto #2 cam gear teeth. Oil is transferred to all cam gear teeth by way of the gear meshing action. From the feed galley, oil is sent to each lifter by individual cross drilled holes so each lifter has it's own oil flow. Restrictions in the lifter assemblies lower the amount of oil up the pushrods to the rocker arms. Oil flows up the pushrods into the rocker arms where rocker arm bushings and valves are lubed. This is the end of oil pump pressure in the top end. Oil is also sent from the upper feed galley down to the pinion bushing / shaft to a hole in the right flywheel then crankpin / lower rod bearings. This is the lower end of oil feed pressure.
+Oil pump feed gerotors send pressurized oil up through a cavity in the filter housing via one external hose to the oil filter pad. \\ The oil leaves the filter and is routed past a check ball (opening at 4-6 PSI) in the filter adapter and through a passage in the upper case's oil feed galley. 1992-up engines do not use an oil pressure bypass system. The high pressure oil bypass was deleted with the addition of a cam squirter hole drilled from the upper cam case through to the upper feed galley. A (.060") hole from the upper feed galley sprays oil onto #2 cam gear teeth. Oil is transferred to all cam gear teeth by way of the gear meshing action. From the feed galley, oil is sent to each lifter by individual cross drilled holes so each lifter has it's own oil flow. Restrictions in the lifter assemblies lower the amount of oil up the pushrods to the rocker arms. Oil flows up the pushrods into the rocker arms where rocker arm bushings and valves are lubed. This is the end of oil pump pressure in the top end. Oil is also sent from the upper feed galley down to the pinion bushing / shaft to a hole in the right flywheel then crankpin / lower rod bearings. This is the lower end of oil feed pressure.
 ==== 2004-Up engines ====
@@ Line 331: / Line 365: @@
   * [[techtalk:evo:oil01q|Oil Pressure Switch Removal and Installation]]
-See also [[techtalk:ref:svcproc30#testing_the_oil_pressure_switch|Testing the Oil Pressure Switch]] in the Ref section of the Sportsterpedia. \\
+See also in the REF section of 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]] \\
 The oil pressure switch (for the oil light) is a pressure actuated diaphragm type on / off switch basically. \\
@@ Line 366: / Line 403: @@
 |{{:techtalk:evo:oil:oil_pressure_switch_on_88_model_by_kevmic28.jpg?direct&300|}}|{{:techtalk:evo:oil:oil_pressure_switch_on_99_sportster_by_hellhound.jpg?direct&300|}}|{{:techtalk:evo:oil:oil_pressure_switch_on_04_sportster_by_hellhound.jpg?direct&300|}}|
-===== 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). \\
 ===== Oil Check Valve (77-E87)=====
 See [[techtalk:evo:oil01k#oil_check_valve_86-e87|Oil Check Valve (86-E87)]] in the Sportsterpedia. \\
-The Oil Check Valve is located behind the threaded filter adapter in the center of the oil filter mount. The filter adapter I.D. was enlarged on the filter end to accept the check valve. The check valve operation is dependent on receiving filtered oil (through the filter media) to lift the check valve cup and allow oil to pass. Therefore, a stopped up oil filter media condition (not allowing flow or enough flow) may not produce enough oil pressure to open the check valve before the filter bypass opens. \\
+The Oil Check Valve on 1986-E1987 engines is located behind the threaded filter adapter in the center of the oil filter mount. The filter adapter I.D. was enlarged on the filter end to accept the check valve. The check valve operation is dependent on receiving filtered oil (through the filter media) to lift the check valve cup and allow oil to pass. Therefore, a stopped up oil filter media condition (not allowing flow or enough flow) may not produce enough oil pressure to open the check valve before the filter bypass opens. \\
 **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:evo:oil:77-e87_oil_check_valve_1_by_hippysmack.jpg?direct&300|}}|{{:techtalk:evo:oil:86-e87_oil_check_valve_location_2_by_hippysmack.jpg?direct&300|}}|
@@ Line 408: / Line 433: @@
 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. \\
-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. So, it is possible but not likely to have a stuck closed check valve with no oil light on. \\
+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. \\
 ===== Oil Check Ball (L87 and Up) =====
@@ Line 445: / Line 470: @@
 |  Check Ball (26437-86A) L87-91 \\ (replaced by (26437-86B) ) ((photo by Hippysmack))  |  Check Ball (26437-86B) 92-Up ((photo by jordan1200 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/196304-oil-filter-mount-and-check-valve?t=2072806))  |  Check Ball and Spring Kit (33116-86A) for 86 -up Models ((photo by Hippysmack))  |
-====== Wet Sumping / Sit Sumping ======
-See article on [[techtalk:ref:oil10|Wet Sumping]] in the REF section of the Sportsterpedia
 \\

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