Differences

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

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
Last revision Both sides next revision
techtalk:ih:engmech07 [2019/12/04 04:30]
hippysmack [Sub Documents]
techtalk:ih:engmech07 [2021/06/15 01:33]
hippysmack [Sub Documents]
Line 4: Line 4:
 ====== Crankcase Ventilation ====== ====== Crankcase Ventilation ======
 See also in the REF section of the Sportsterpedia:​ \\ See also in the REF section of the Sportsterpedia:​ \\
 +  * [[techtalk:​ref:​engmech04k|Breather Valves (1957-Up)]] (list of breather valve changes)
 +  * [[techtalk:​ref:​engmech07g|Further Study of the Timed Breather Valve]]
 +  * [[techtalk:​ref:​engmech07i|Dissecting the 77-78 Breather (foo-foo) Valve (24634-77)]]
 +  * [[techtalk:​ref:​engmech07s|XR-750 8-Ball Breather Valve]]
 +  * [[techtalk:​ref:​engmech05|Breather Venting / Relocation]]
   * [[techtalk:​ref:​oil10#​refoiling_lubrication|Wet Sumping]]   * [[techtalk:​ref:​oil10#​refoiling_lubrication|Wet Sumping]]
   * [[techtalk:​ref:​oil05#​engine_and_primary_oil_system_modifications|Engine and Primary Oil System Modifications]]   * [[techtalk:​ref:​oil05#​engine_and_primary_oil_system_modifications|Engine and Primary Oil System Modifications]]
 +  * [[techtalk:​ref:​engmech07|IH Crankcase Pressure and Engine Breathing]]
  
-Here's a breakdown of XL & K model breathers, set-up, service and upgrades. ((JimmCapp of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948&​highlight=cam+chest+breather&​page=5)) \\ 
  
-52-76 models: \\ +====== ​Timed Breather Valve (57-76) ​======
-  * Timed Rotary Breather +
-  * Design & Function +
-    * Integral with the oil pump, timed to engine rotation. +
-    * 72 & up timing +
-      * Opens 25 degrees ATDC closes 85 degrees ABDC +
-    * 52-71 +
-      * Breather timing was less duration. +
-      * Rotary breather connects flywheel area to gearcase. +
-      * Slinger separates oil from air. +
-    * 52-62 +
-      * Special slinger on generator. +
-      * Spring loaded bushing in case rubbed end of slinger. +
-      * Breather pipe in gearcase cover open to atmosphere. +
-    * 63-76 +
-      * Washer - 1 5/8" dia. on end of generator. +
-      * 1/​16-3/​16"​ Clearance +
-      * Service +
-        * Pump had to be timed, line up these marks; +
-          * Ignition timing mark - center of window. +
-          * Dot on rotary breather should be centered in pump housing notch. +
-          * Changed by repositioning of pump gear to drive gear on pinion shaft. +
-    * 63-76 Slinger washer distance +
-      * 1/​16-3/​16"​ +
-      * Increase by grinding generator gear or add generator gaskets. +
-      * Decrease by shimming washer. +
-    * Updates +
-      * 52-71 Breathers +
-        * Install 72-76 pump. +
-        * Changes breather timing - benefit. +
-        * Modify feed supply. +
-        * Plug old fitting in case. +
-        * Run feed to back of new pump. +
-        * One Way Breathers 77-85. +
-    * Design +
-      * 77-78 - PCV type valve. +
-        * Inline with breather pipe. +
-        * 1-5/8" Slinger washer. +
-      * 79-E81 +
-        * Stainless reed valve +
-        * Mounted in gearcase cover. +
-        * 1-5/8" Slinger washer. +
-        * Breather hose to air cleaner '79 & up +
-      * L81-85 +
-        * Rubber umbrella valve. +
-        * Very efficient. +
-        * Mounts in gear case cover. +
-        * 1-3/4" Slinger washer. +
-      * All 79-85 breather systems connect to air cleaner. +
-    * Service and troubleshooting +
-    * Inspection:​ +
-     * All valves should flow one direction only. +
-     * Slinger distance must be 1/​16-3/​16"​. +
-     * Too little - increased crankcase pressures = oil leaks. +
-     * Too much - slinger won't separate oil = oil carry over +
-     * If bike smokes check breather valve operation. \\ +
-     * If it sticks open there will be no crankcase vacuum to help evacuate top end oil +
-   * Updates +
-     * 79-early 81 +
-     * Rubber umbrella breather is a retrofit, with 1-3/4" slinger washer. +
-       * Better breathing, less stiff than the metal reed and better sealing - doesn'​t stay open due to metal fatigue +
- +
-====== Breather Valve ======+
 \\ \\
-The later style system ​is just like your car. ((mrmom9r of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1204854&​page=4)) ​\\  +===== Sub Documents ===== 
-A deep sump was added to 77> casings and the scavenge side of the oil pump simply pulls the oil from there. \\ + 
-Holes were added between the crankcase and the gearcase / cam chest and crankcase pressure is vented to atmosphere from there. \\ +  * [[techtalk:​ih:​engmech07a|Timing the 76< Breather Valve]] 
-(much the way your car's crankcase is vented out the top thru the valve covers) \\ + 
-  +57-76 engines breath and scavenge oil from the same oil galley in the rear of the sump. \\ 
-The shallow sump, timed breather system, comes from the aviation world of old. \\+<​blockquote>​The shallow sump, timed breather ​system, comes from the aviation world of old. ((mrmom9r of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1204854&​page=4)) \\ 
 Piston driven aircraft had to be able to evacuate the oil from the crankcase regardless of engine altitude and that system does that. \\ Piston driven aircraft had to be able to evacuate the oil from the crankcase regardless of engine altitude and that system does that. \\
 At the time Harley adapted that system they were copying the highest engine technology of the day. \\ At the time Harley adapted that system they were copying the highest engine technology of the day. \\
 They just took too long to abandon it as technology advanced. \\ They just took too long to abandon it as technology advanced. \\
 +Documents from HD Racing from the period show no HP gain between the 2 ironhead systems when the breather is properly timed ( which didn't happen a lot). \\
 +</​blockquote>​
  
-The sump system was brought into production to eliminate ​the need to time a breather to save time on the assembly line. \\ +The rotary breather valve is integrated with the oil pump. The gear on top of the valve also operates the oil pump. \\ 
-Documents from HD Racing from the period show no HP gain between ​the 2 systems when the breather is properly timed ( which didn't happen a lot). \\ +The breather valve connects ​the flywheel area to the gearcase. \\
-===== 76< Timed Breather Valve ===== +
-==== Sub Documents ==== +
-  * [[techtalk:​ih:​engmech07a|Timing the 76< Breather Valve]]+
  
 The rotary breather valve functions to relieve pressure in the crankcase caused by the downstroke of the pistons and it controls the flow of oil in the lubrication system. \\ The rotary breather valve functions to relieve pressure in the crankcase caused by the downstroke of the pistons and it controls the flow of oil in the lubrication system. \\
-It is timed to open on the downstroke of the pistons. ((1960 HD FSM pg 3a-15)) \\+It is timed to engine rotation and opens on the downstroke of the pistons. ((1960 HD FSM pg 3a-15)) \\
 This allows crankcase exhaust air pressure to expel the scavenge oil from the crankcase breather oil trap into the gearcase. \\ This allows crankcase exhaust air pressure to expel the scavenge oil from the crankcase breather oil trap into the gearcase. \\
 The breather valve then closes on piston upstroke, creating vacuum in the crankcase. \\ The breather valve then closes on piston upstroke, creating vacuum in the crankcase. \\
Line 96: Line 38:
 Any oil still in suspension with the air on the way to the breather tube is separated by an oil slinger on the generator drive gear. \\ Any oil still in suspension with the air on the way to the breather tube is separated by an oil slinger on the generator drive gear. \\
  
-A street oil pump has 2 slots and is driven at 1/2 engine ​speed. ​((thefrenchowl of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=448751)) \\ +|Left is the unmodified ​1/speed R \\ valveRight is the 1000 stock.|R model is the left one.| 
-A racing oil pump has 4 slots and is driven at 1/4 engine speed\\ +|{{:​techtalk:​ih:​engmech:​cc_flow_4_by_dr_dick.jpg?​direct&​200|}}|{{:​techtalk:​ih:​engmech:​cc_flow_5_by_dr_dick.jpg?​direct&​300|}}|
-All 4 stroke engines takes two revolutions before you come back to the timing marks being all aligned.+
  
-How the volume compares when the breather opens as to when it closes: ((Dr Dick of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1204854&page=3)) \\ +===== 1956-1959 Breather Valve ===== 
-If we knew that, we'd have a much clearer picture ​of what actually happens. \\ +  * Breather timing and duration: 
-This diagram shows the volume swept by piston action in a 1000cc motor. \\ +    * Opens 25° (ATDC) and Closes at (BDC). ((thefrenchowl ​of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2077939&page=2)) 
-It shows how much displacement is changed ​from min volume ​(0 cubic inches) to max volume(56.2 ci more than min). \\ +  * Duration - 155° 
-{{:​techtalk:​ih:​engmech:​breather_valve_drawing_1_by_dr_dick.jpg?​direct&​400|}} ((drawing by Dr Dick of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1204854&​page=3)) \\+  * 180° of vacuum ​from front (BDC) to front (TDC). 
 +===== 1960-1971 Breather Valve =====
  
-There'​s only 1.2 cubic inches of net outward flow per revolution. \\ +  * Breather timing and duration: 
-(ignoring the dynamics ​of the inertia that the moving column imparts to the actual ​net movement\\ +    * Opens 25° (ATDC) and Closes at (BDC) ((thefrenchowl ​of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2077939&​page=2)
-So the actual movement is great but the net change is small\\ +  * Duration - 155°. 
-How much actual movement\\ +  * Slot widths: ((chevelle of the XLFORUM http://​xlforum.net/​forums/​showthread.php?t=989934&​page=2)) 
-About 45 ci on down stroke and about another 45 on the up for a total of app90 ci per rev trying to squeeze thru the open breather\\ +    * Slot in pump body: .345" 
-(which is fully open for exactly 1/2 the time of the 'just open' ​to 'just close' total time\\+    * Slot in pump gear: .375" ​ 
 +  * 180° of vacuum from front (BDC) to front (TDC).
  
-90 ci per revolution is about 1-1/2 quarts per revolution. \\ +===== 1972-1976 Breather Valve =====
-Multiply that by 5000 rpm and you get 7500 quarts per min. \\ +
-That's almost 2000 gallons per min trying to get thru the breather. \\ +
-Obviously that ain't happening and the highly revered 1/4 speed (R) pump has a way smaller opening yet than the street pump. \\+
  
-The pics below show the flow from the flywheel cavity to the return ​pump (applies ​to 76< only). \\ +  * Breather timing and duration: 
-In stock configuration,​ most all used oil ends up in the flywheel cavity. \\ +    * Opens 20°-25° (ATDC) and closes 85°-90° (ABDC). ((thefrenchowl of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2077939&​page=2)) 
-The small amount that gets supplied to the upper pushrod ball/socket goes into the gearcase. \\ +  * Duration - 245°. 
-While the splash oil to the exhaust valves enters ​the crankcase through ​the head drains. \\ + * Slot widths: ((chevelle of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=989934&​page=2)) 
 +    * Slot in pump body: .345"​ 
 +    * Slot in pump gear: .625"​ 
 +    * 90° of vacuum from 90° (ABDC) to front (TDC)
 +====== One Way Breather Valve (77-85) ====== 
 +The one way breather style system is more like a car PCV system. ((mrmom9r of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1204854&​page=4)) Unlike an auto PCV, a Sportster has a faster acting type one way valve. \\  
 +A deep (dry) sump was added to 77> casings and the scavenge side of the oil pump pulls the oil from the scavenge port in the rear of the sump area. \\ 
 +Holes were added between ​the crankcase and the gearcase wall (much the way your car's crankcase is vented out the top thru the valve covers) \\ 
 +Those holes in the walls are an open passage for crankcase pressure ​into the gearcase. \\ 
 +So the gearcase is also pressurized. Crankcase pressure is sent thru the one way valve in the cover and then vented to atmosphere out the vent. \\ 
 +So, 77-up engines breath and scavenge oil from separate places. \\
  
-There are only 2 areas that get supply (feed) oil pumped to themthe crankpin and the rocker shafts. ((photos by Dr Dick of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1204854&​page=3)) \\+Howevercrankcase ventilation works a little differently on these motors than a Chevy. ((aswracing ​of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1468237)) \\ 
 +What you see on cars is an inlet, generally coming from the air filter, into the motor. Then an outlet, regulated by a PCV valve, going into the intake manifold. \\ 
 +So it's designed to flow a little air through the system. \\ 
 +The other thing is that a V8 crankcase stays at a constant volume, because for every piston going up there'​s a piston going down. \\ 
 +On a Sportster motor there'​s no air inlet. The engine vents into the intake flow on the upstream side of the carb instead, where there'​s much less vacuum. \\ 
 +It's not designed to flow air through it. What's more, the crankcase volume is constantly changing. There are check valves in line with the breather outlets. \\ 
 +Their function is to expel the air when the pistons go down but then restrict the air from entering the motor when the pistons go up. \\ 
 +The result is that beyond the first revolution, if the check valves are working properly, all you see out the breathers is the pulsating pressured air. \\ 
 +On a good motor, it's very little. But if the check valves are not working properly, the motor goes into an inhale/​exhale mode. \\ 
 +That causes a whole lot air movement and it also causes a lot of oil to get carried out at the same time. \\ 
 +Many cases of excess breather oil is caused by poorly functioning check valves.
  
-|{{:​techtalk:​ih:​engmech:​cc_flow_1_by_dr_dick.jpg?​direct&​300|}}|{{:​techtalk:​ih:​engmech:​cc_flow_2_by_dr_dick.jpg?​direct&​300|}}|{{:​techtalk:​ih:​engmech:​cc_flow_3_by_dr_dick.jpg?​direct&​300|}}|+A mixture of crankcase air and oil mist is produced on each piston down stroke\\ 
 +This forced mixture helps to splash lube the moving parts in the engine\\  
 +It also creates unwanted pressure in the engineThe oil mist is then separated from the crankcase air and the excess air pressure is vented out of the engine. \\ 
 +77-85 engines vent through a valve in the cam cover. \\ 
 +There were several changes made of the valve itself, but they operate on the same principle., a one way breather valve. \\ 
 +Where 76< engine crankcase volume is the simply the crankcase itself, 77> engines have the added volume of the gearcase as well. \\ 
 +With the non-timed breather valve closing at BDC, the bottom end volume has 180° of vacuum starting from front (BDC) to front (TDC). \\
  
-|Left is the unmodified 1/4 speed R \\ valve. Right is the 1000 stock.|R model is the left one.| +===== 1977-1978 Breather Valve ===== 
-|{{:​techtalk:​ih:​engmech:​cc_flow_4_by_dr_dick.jpg?​direct&​200|}}|{{:​techtalk:​ih:​engmech:​cc_flow_5_by_dr_dick.jpg?​direct&​300|}}| +See also [[techtalk:​ref:​engmech07i|Dissecting the 77-78 Breather ​(foo-foo) ​Valve (24634-77)]] for disassembly pics of the valve itself. \\
- +
-|{{:​techtalk:​ih:​engmech:​cc_flow_6_by_dr_dick.jpg?​direct&​300|}}|{{:​techtalk:​ih:​engmech:​cc_flow_7_by_dr_dick.jpg?​direct&​300|}}|{{:​techtalk:​ih:​engmech:​cc_flow_8_by_dr_dick.jpg?​direct&​300|}}| +
-\\ +
- +
-There are only 3 rotor and tower slot widths for all 1937-76 4-cam engines (45, K, KH, XL, UL), which determine the complete breather timing interval. ((kitabel of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2073932&​page=87)) \\ +
-  - Rotor .375" (88°) + tower .34375"​ (81°) ​169°: \\ all non-R 1937-71 engines; the exact opening-closing points vary between engines; 1952-71 K &c. slots are taller than 45 & UL. +
-  - Rotor .594" (146°) + tower .34375"​ (81°) ​227°: 1972-76 XL; these slots are also taller than 45 & UL. +
-  - Rotor .214" (99°) + tower .269 (125°) ​224°: all 1954-? KR, KHR, XLR (many mods to this) +
- +
-===== 77-78 Breather Valve =====+
  
 WHAT IS IT? WHAT IS IT?
 +
 +  * The complete assembly is part# (24633-77). The valve itself is (24634-77).
 +  * Thread size at cam cover is 5/​8"​-11. ((ericfreeman of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1003815))
   * The slang term "​FooFoo"​ comes from the annoying sound that it makes when it gets clogged up with oil residue. ((IronMick of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1332902&​page=3))   * The slang term "​FooFoo"​ comes from the annoying sound that it makes when it gets clogged up with oil residue. ((IronMick of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1332902&​page=3))
   * The engine breather (or crankcase vent) is to allow air out of the lower crankcase, but not in, as the pistons rise and fall. ((Hopper of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948)) \\ Without some kind of controlled breather, the lower end would become a 1,000cc air compressor, robbing the engine of several horsepower. \\ Old time tuners like Jerry Branch, Tom Sifton and Dick O’Brien paid much attention to the engine breather. \\ They knew it could give them extra horsepower if set up right.   * The engine breather (or crankcase vent) is to allow air out of the lower crankcase, but not in, as the pistons rise and fall. ((Hopper of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948)) \\ Without some kind of controlled breather, the lower end would become a 1,000cc air compressor, robbing the engine of several horsepower. \\ Old time tuners like Jerry Branch, Tom Sifton and Dick O’Brien paid much attention to the engine breather. \\ They knew it could give them extra horsepower if set up right.
-  *  One thing not to do with an engine breather is to simply plumb a hose to the crankcase without some kind of one-way valve or timed breather valve. \\ It is commonly done, but it wastes power and is not good for your engine. ​+  *  One thing not to do with an engine breather is to simply plumb a hose to the crankcase without some kind of one-way valve or timed breather valve. \\ It is commonly done, but it wastes power and is not good for your engine.
  
 WHERE IS IT? ((Hopper of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948)) \\ WHERE IS IT? ((Hopper of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948)) \\
-  * **Pre-1977** +
-      * There is a timed breather valve built into the oil pump drive, which vents crankcase pressure into the cam timing chest. \\ A six-inch metal tube hanging down from the timing cover near the generator drive, at the 6 o’clock position vents that controlled pressure to atmosphere. \\ A metal disc on the end of the generator drive gear centrifugally separates oil from the air as it is discharged overboard. ​+
   * **1977-78 only** ((Hopper)) ((HD Service Bulletin #M-708 dated December 1, 1976)) \\   * **1977-78 only** ((Hopper)) ((HD Service Bulletin #M-708 dated December 1, 1976)) \\
       * The timed breather on the oil pump drive was dropped. \\ A new design breather valve (24633-77) was used in late 1977 model XL/XLCH/XLT engines produced around October 15, 1976. \\ All 1000cc engine numbers (3A, 4A or 2G) 27940H7 and above had the new breather valve. \\ It serves the same function as the gear driven breather valve used on 1976 and earlier engines to maintain a partial vacuum in the engine and prevent oil leakage. \\ Due to it's improvements in doing so, it was suggested to be retrofitted to all 1977 XL & XLCH engines.       * The timed breather on the oil pump drive was dropped. \\ A new design breather valve (24633-77) was used in late 1977 model XL/XLCH/XLT engines produced around October 15, 1976. \\ All 1000cc engine numbers (3A, 4A or 2G) 27940H7 and above had the new breather valve. \\ It serves the same function as the gear driven breather valve used on 1976 and earlier engines to maintain a partial vacuum in the engine and prevent oil leakage. \\ Due to it's improvements in doing so, it was suggested to be retrofitted to all 1977 XL & XLCH engines.
Line 154: Line 112:
       * The new valve opens at 4-6 PSI whereas the old valve opens at 2-4 PSI. \\ Pumps having the new valve are identified with a green dot. \\ The existing 0-ring (26433- 77) was used for both new and old valves.       * The new valve opens at 4-6 PSI whereas the old valve opens at 2-4 PSI. \\ Pumps having the new valve are identified with a green dot. \\ The existing 0-ring (26433- 77) was used for both new and old valves.
       *  An external non-return valve was plumbed into the vent tube sticking down from the timing cover at the generator drive. \\ This allows air out, but not in. It is sometimes referred to as the foo-foo valve. \\ Searching the XLFORUM for __foo foo valve__ or __foo-foo__ will lead to extensive discussions of this mystical device.       *  An external non-return valve was plumbed into the vent tube sticking down from the timing cover at the generator drive. \\ This allows air out, but not in. It is sometimes referred to as the foo-foo valve. \\ Searching the XLFORUM for __foo foo valve__ or __foo-foo__ will lead to extensive discussions of this mystical device.
 +    * **Replacement options**:
 +      * It's a possible option for the 77-78 foofoo valve  to be replaced with an external breather valve. \\ If you want to go this route, remove the internal valve as it will also change crankcase pressure with 2 valves in line. \\ Then, you might want to consider installing something like the external Krankvent or others. \\ [[techtalk:​ref:​engmech05d|Click here]] to see the Converting Head Breathers to Cam Chest Breather page in the Sportsterpedia. \\ That page is for an Evo conversion to cam chest breathing but the Krankvent and plumbing is shown. \\ You can also review this page in the Sportsterpedia ​ [[techtalk:​ref:​engmech05|Breather Venting / Relocation]] (especially the sub documents at the top of the page)
  
 +| 77 Cam Cover Breather Compartment. ((photo by joynny77 of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=610444&​page=4)) |  See "​Dissecting the 77-78 Breather (foo-foo) Valve (24634-77)"​ for more pics and dims. ((photos by Hippysmack)) ​ ||
 +|{{:​techtalk:​ih:​engmech:​1977_crankcase_breather_compartment_by_johnny77.jpg?​direct&​300|}}|{{:​techtalk:​ref:​engmech:​77-78_xl_foofoo_valve_24634-77_pic1_by_hippysmack.jpg?​direct&​300|}}|{{:​techtalk:​ref:​engmech:​77-78_xl_foofoo_valve_24634-77_pic12_by_hippysmack.jpg?​direct&​300|}}|
 +
 +|  77-78 Crankcase Breather Valve ((photo by Hopper of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=1960632)) ​ |||
 |{{:​techtalk:​ih:​oil:​77-78_ext_foo_foo_valve_1_by_hopper.jpg?​direct&​300|}}|{{:​techtalk:​ih:​oil:​77-78_ext_foo_foo_valve_2_by_hopper.jpg?​direct&​300|}}|{{:​techtalk:​ih:​oil:​77-78_ext_foo_foo_valve_3_by_hopper.jpg?​direct&​300|}}| |{{:​techtalk:​ih:​oil:​77-78_ext_foo_foo_valve_1_by_hopper.jpg?​direct&​300|}}|{{:​techtalk:​ih:​oil:​77-78_ext_foo_foo_valve_2_by_hopper.jpg?​direct&​300|}}|{{:​techtalk:​ih:​oil:​77-78_ext_foo_foo_valve_3_by_hopper.jpg?​direct&​300|}}|
-|  77-78 Crankcase Ventilation Valve ((photo by Hopper of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=1960632)) ​ | 
  
-===== 1979-E1982 =====+  * This vent line mod was done due to problems fitting the stock tube as it hit the exhaust pipes. 
 +    * Thread size for the breather fitting is 5/8"-11. 
 +    * A piece of aluminum threaded rod, cut a small length to thread into the breather and drill / tap the hole for an 1/8" pipe thread. 
 +    * A 45 ° hose barb fitting was installed to connect a length of hose that leads back along the frame. \\ This way the oil mist gets directed out back and doesn'​t collect along the frame and engine.
  
-      * The external foo-foo valve and the six-inch metal vent tube at the front of the timing cover were done away with. \\ Insteada one-way foo-foo valve was built inside the timing cover (26909-79A),​ (26909-82). \\ A rubber breather hose then ran from the generator drive area of the timing cover, at the 9 o’clock position. \\ It connected to the stock air filter so that any oil mist was fed back through the engine, making the EPA pollutocrats more happier. \\ (than they were with the idea of engine oil spraying out into the atmosphere) \\ The generator had a (1-5/​8" ​O.D.) oil separator washer on the end of the armature shaft((HD Service Bulletin #M-848 dated April 9, 1982))+|  Stock tube removedfitted ​with 1/​8" ​45 deg barb fitting((photos by ericfreeman ​of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1928882))  || 
 +|{{:​techtalk:​ih:​engmech:​foofoo_vent_mod_pic1_by_ericfreeman.jpg?​direct&​300|}}|{{:​techtalk:​ih:​engmech:​foofoo_vent_mod_pic2_by_ericfreeman.jpg?​direct&​300|}}|
  
-Here is a pic of IronMick's internal ​foo-foo ​in his post-79 model on the left. \\ +===== 1979-E1982 Breather Valve===== 
-You can see the 9 oclock fitting and the 6 oclock fitting both enter the same cavity. \\ + 
-The oil slinger is the big fat washer on the end of the generator in the (Rpic below. \\ +  * **Reed Valve Assembly (26909-79)**. 
-{{techtalk:​ih:​oil:​ihcamcoverxlf.jpg?​direct&​250|}} ​((photo by ryder rick of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948&​page=2)) {{:techtalk:ih:engmech:​oil_slinger_by_screwloose.jpg?​direct&​300|}} ​((photo by Screwloose of the XLFORUM http://xlforum.net/​forums/​showthread.php?​t=1979566&​highlight=float&​page=5)) \\+    * Breather vent fitting thread size at the cam cover is 1/8" NPT. ((IronMick ​of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1003815)) 
 +    * The external ​foo-foo ​valve and the six-inch metal vent tube at the front of the timing cover were done away with. \\ Instead, a one-way foo-foo valve was built inside ​the timing cover. \\ A rubber breather hose then ran from the generator drive area of the timing cover, at the 10 o’clock position. \\ It connected to the stock air filter so that any oil mist was fed back through ​the engine, making the EPA pollutocrats more happier. \\ (than they were with the idea of engine oil spraying out into the atmosphere) \\ The generator had a (1-5/​8"​ O.D.) oil separator ​washer on the end of the armature shaft. ​((HD Service Bulletin #M-848 dated April 9, 1982)
 +    * The breather valve is a simple reed valve with a flap made of spring steel over a hole. \\ Unless it's visibly damaged, there'​s no reason to mess with it. ((BigMek ​of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=5843330)) \\ If it stops up, you can try and spray some WD-40 in the hole to clear it. 
 +  * **Removal**: 
 +    * The reed cam be removed with a standard bushing / bearing puller ​ with a 5/​8"​. 
 +  * **Replacement options / mods**: 
 +    * In L1982, a new style crankcase breather valve was used in production\\ The breather valve kit (26909-79A), which is functionally more durable and quieter than the early style reed valve, will fit 1979-E82 models. \\ The late style breather valve incorporates a rubber umbrella valve attached to the base plate along with a larger diameter oil slinger washer. \\ The oil slinger washer is bigger ​(1-3/4" OD). \\ These parts, used together, will replace ​the early style reed valve assembly and smaller diameter oil separator washer. \\ 
 +    * It's a possible option for the 79-85 breather valve to be replaced with an external breather valve. \\ If you want to go this route, remove the internal valve as it will also change crankcase pressure with 2 valves in line. \\ Then, you might want to consider installing something like the external Krankvent or others. \\ [[techtalk:ref:​engmech05d|Click here]] to see the Converting Head Breathers to Cam Chest Breather page in the Sportsterpedia\\ That page is for an Evo conversion to cam chest breathing but the Krankvent and plumbing is shown\\ You can also review this page in the Sportsterpedia ​ [[techtalk:​ref:​engmech05|Breather Venting / Relocation]] (especially the sub documents at the top of the page) 
 +    * [[techtalk:​ref:​engmech05i#​refengine_mechanicals_-_sub-05i|Click here]] to see the page on Adding a Secondary Vent Hose at the 6:00 Position. ​\\ This mod has been done with agreeable results to improve breathing.
  
 Here's the reed valve and the back side. \\ Here's the reed valve and the back side. \\
 {{:​techtalk:​ih:​engmech:​79_breather_valve_by_tobybott.jpg?​direct&​350|}} ((photo by tobybott of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=982127&​highlight=breather#​post982127)) {{:​techtalk:​ih:​engmech:​reed_valve_by_lodkolv.jpg?​direct&​300|}} ((photo by lodkolv of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=113861&​highlight=breather&​page=2)) \\ {{:​techtalk:​ih:​engmech:​79_breather_valve_by_tobybott.jpg?​direct&​350|}} ((photo by tobybott of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=982127&​highlight=breather#​post982127)) {{:​techtalk:​ih:​engmech:​reed_valve_by_lodkolv.jpg?​direct&​300|}} ((photo by lodkolv of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=113861&​highlight=breather&​page=2)) \\
  
-===== L1982-1985 =====+(Left) ​E82 cover with the breather removed showing compartment below. ((photo by wlkilmer of the XLFORUM)) \\ 
 +(Right) - 81 Cam Cover Breather Compartment (with the rubber umbrella valve upgrade). ((photo by joynny77 of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=610444&​page=4)) \\ 
 +{{:​techtalk:​ih:​engmech:​1982_breather_compartment_oil_drainback_hole_by_wlkilmer.jpg?​direct&​300|}} {{:​techtalk:​ih:​engmech:​1981_crankcase_breather_compartment_w_update_rubber_valve_by_johnny77.jpg?​direct&​300|}} \\
  
-      * The internal crankcase breather valve was redesigned to incorporate a rubber umbrella valve attached to the base plate along with a larger diameter (1-3/4" O.D.) oil separator washer on the generator armature. ((HD Service Bulletin #M-848 dated April 9, 1982))+===== L1982-E1984 Breather Valve =====
  
-Many of these bikes with custom air filters simply run that hose down to the bottom of the frame and let the oil mist blow out in the time honored manner. \\ +  * **Breather valve (26909-82)**. 
-That is fine too, as long as you are not an EPA man. \\ +    * The crankcase breather valve was redesigned ​to incorporate a rubber umbrella valve attached to a metal disc installed ​in the base plate. \\ (along with a larger diameter 1-3/4" O.D. slinger washer) 
 + 
 +{{:​techtalk:​ih:​engmech:​83_cam_cover_breather_valve_by_hippysmack.jpg?​direct&​300|}} ((photo by Hippysmack)) ​\\ 
 +===== L1984-1990 Breather Valve ===== 
 + 
 +  * **Breather valve (26856-82)**  
 +    * The generator was moved and an oil filter was mounted in it's place. The oil slinger system was deleted for L84-up models. 
 +    * The crankcase breather valve was redesigned to incorporate a baffle tube assembly (26917-84) with a rubber umbrella valve inside it.
  
 The pic on the left shows the breather line coming out at the 10 o'​clock position going up to the air cleaner. \\ The pic on the left shows the breather line coming out at the 10 o'​clock position going up to the air cleaner. \\
Line 182: Line 166:
 {{:​techtalk:​ih:​engmech:​85_foofoo_2_by_spamer80.jpg?​direct&​300|}} ((photo by spammer80 of the XLFORUM)) ​ {{:​techtalk:​ih:​oil:​85_cam_cover_1_by_billeuze.jpg?​direct&​300|}} ((photo by billeuze of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1103082)) {{:​techtalk:​ih:​engmech:​85_foofoo_2_by_spamer80.jpg?​direct&​300|}} ((photo by spammer80 of the XLFORUM)) ​ {{:​techtalk:​ih:​oil:​85_cam_cover_1_by_billeuze.jpg?​direct&​300|}} ((photo by billeuze of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1103082))
  
-Both the 10 o'​clock and 6 o'​clock outlets come out of the same chamber ​that'​s ​controlled by the internal one-way crankcase ​valve. ((83XLX of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948&highlight=cam+chest+breather&page=10)) \\ +**Umbrella check valve**: ((Gary E of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2071387&​page=8)) \\ 
-When both are opened, the crankcase pressure ​can evacuate more quickly / completely. \\ +Outside diameter: \\ 
-Opening ​the 6 o'​clock hole doesn'​t bypass ​the factory crankcase venting arrangement. \\ +26856-82 - 1.25" \\ 
-A small amount ​of oil occasionally drips from it. \\ +Edge thickness (1/8" in average): ((Gary E of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2071387&​page=8)) \\ 
-But that's better than having it accumulate in the air filter ​and blowing all over the right side of the bike. \\ +26856-82 - 0.036" \\ 
-Plus, the extra vent seems to let the motor wind up a little more freely. \\ + 
-No filter ​is needed when plumbing ​to the 6 o'​clock ​breather ​line. ((trappnman ​of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948&​highlight=cam+chest+breather&page=12)) \\ +The pic below shows the left side (filter side) that faces into the cam box. \\ 
-They just collect oil and drip. \\ +It'​s ​center inside diameter is slightly larger than the 1.25" OD (-82) umbrella ​valve. ​\\ 
-You can use an old inline glass gas filter ​(remove ​the filter itself), hooked ​the vent hose to it, and zip-tie it under the frame. \\ +The two '​C'​ shaped slots that do the breathing have an OD of 1". \\ 
-It'll be horizontal ​to the bike and will collect ​the oil so it won'​t ​drip all over . \\ + 
-And it'​ll ​vent freely with no filter or other obstructions. \\+|{{:​techtalk:​evo:​oil:​breather_baffle_tube_by_gary_e.jpg?​direct&​300|}}|{{:​techtalk:​evo:​oil:​86_crankcase_vent_3_by_norsexl.jpg?​direct&​300|}}| 
 +|  Breather Baffle Tube (26917-84) ​((photo by Gary E of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2071387&page=8http://​xlforum.net/​forums/​showthread.php?​t=2071387&page=8))  ​| ​ Cap, tube and umbrella ((photo by norseXL of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=72099&​page=25)) ​ | 
 + 
 +===== 1979-1990 Breather Valve Replacement Options / Mods ===== 
 + 
 +    * It's a possible option for the 79-90 breather valve to be replaced with an external breather valve. ​\\ If you want to go this routeremove ​the internal valve as it will also change ​crankcase pressure ​with 2 valves in line. \\ Then, you might want to consider installing something like the external Krankvent or others. \\ [[techtalk:​ref:​engmech05d|Click here]] to see the Converting Head Breathers to Cam Chest Breather page in the Sportsterpedia. \\ That page is for an Evo conversion to cam chest breathing but the Krankvent and plumbing is shown. \\ You can also review this page in the Sportsterpedia ​ [[techtalk:​ref:​engmech05|Breather Venting / Relocation]] (especially the sub documents at the top of the page) 
 +    * [[techtalk:​ref:​engmech05i#​refengine_mechanicals_-_sub-05i|Click here]] to see the page on Adding a Secondary Vent Hose at the 6:00 Position. \\ This mod has been done with agreeable results to improve breathing. 
 + 
 + 
 +====== Oil Slinger ====== 
 +==== Sub Documents ==== 
 +  * [[techtalk:​ih:​engmech07l|Dr Dick on the slinger ​and oil loss]] 
 + 
 +Crankcase exhaust air escapes from the gearcase through ​the external breather tube((1959-1969 HD Sportster FSM pg 3A-15)) ​\\ 
 +Any oil carried still carried by exhaust air is separated from the air by an oil slinger on the generator drive gear. \\ 
 +The oil slinger ​is powered by the generator and deflects oil away from air leaving the breather outlet ​to atmosphere. \\ 
 +It spins oil away from the breather ​hole by centrifugal force and separates the oil mist in suspension with the exhausting air\\ 
 + 
 +**Factory Oil Slingers**: ​((Dr Dick of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1660412&page=3)) ((Moon Wolf of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=2195143#​post2195143)) ((thefrenchowl of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=2195143#​post2195143)) \\ 
 +  * **1957** used the model 52 generator, no nut or washer, ​and a daisy wheel gear (31071-52A) pinned to the generator shaft. 
 +  * **1958-1962** used a daisy wheel gear (31071-58), an integral slinger / genny gear bolted to the shaft. \\ It looks like a gear with a tinker toy connector glued on the end. \\ It's a lathe machined affair combined with a spring loaded sleeve in the cover. \\ These are great gears but no one repops them and they are expensive and hard to find. 
 +    * Just get rid of the timing cover sliding bush/spring if you want to upgrade to the big washer instead. ​((thefrenchowl of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=2195143#​post2195143)) \\ The sliding bushing assembly makes the early slinger works as a "​labyrinth"​ since the air has to travel through its center to get out. \\ That's why it's a better set up than the simpler washer setup. ​It doesn't allow for any oil to escape except if your engine is totally wetsumped. \\ But the early slinger ​will work without ​the sliding bushing, just not as good. \\ And you can'​t ​use the sliding bushing with the washer setup. 
 +  * **L1962-1978** used a more standard looking 14T gear (31073-63) used with a 1-5/8" washer style slinger (31067-63). \\ Not as good but a lot cheaper to make. The washer itself looks to be just a normal fender washer. \\ You may find an in use washer with grooves stamped in it. Grooves are an old mod done by owners/​wrenches (not the factory). \\ It is large enough in diameter to make installing the generator tricky at times. \\ 5/16" fender washers come in 3 sizes. 1.375" (common), 1.500" (hard to find), 1.625" (real hard to find). \\ OEM is 1.625" although the 1.500" washer usually works fine. The 1.375" washer may pass more oil out the vent than the bigger ones. \\ 
 +  * **1979-1981** used gear (31073-63A) with the 1-5/8" slinger washer (31067-63). 
 +  * **1982-E1984** used the same gear (31073-63A) with a 1-3/4" slinger washer (31066-82) to accommodate the larger crankcase breather valve.
  
-{{:​techtalk:​ih:​engmech:83_xlx_crankcase_vent_mod_by_83xlx.jpg?direct&300|}} ​((photo by 83XLX of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948&​highlight=cam+chest+breather&​page=3))+To inspect or replace the slinger washer, remove the two bolts from the cam cover that hold the generator. ((randy3934 of the XLFORUM http://xlforum.net/​forums/​showthread.php?t=1651226&highlight=slinger&​page=2)) \\ 
 +Remove the wires from the generator and with a little fiddeling around, the generator will come out. The washer is on the end of the armature. \\ 
 +Make sure to put a new grade 8 nylock nut on if you remove the old one. They should only be used once or they lose their grip in that hot, oily environment. ​((Hopper ​of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1651226&​highlight=slinger&​page=3)) ​\\
  
-====== Breather Valve Alternatives ======+Check the oil separator bushing to bore fit in the cover. It should be a light press fit. \\ 
 +If it is loose, you can probably remove it, clean up the boss with brake cleaner and reinstall the bushing with Loctite or epoxy. ((shovithead of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=1651226&​highlight=slinger&​page=3)) \\
  
-  * There is a product called a Krankvent that can be plumbed into the lower, 6 o’clock position as an alternative to a stock foo-foo valve. But they are not cheap. +|1952-1956 K/KH or 1957 XL Sportster (pinned) \\ Generator Drive Gear / Oil Slinger ((photo courtesy ​of Ebay sellerJDVintagellc[[https://​www.ebay.com/​str/​jdvintagellc?​_trksid=p2047675.l2563|Link to Ebay Store]] ))|1958-1962 Sportster (threaded) \\ Generator Gear / Oil Slinger (31071-58) ((photo by Dr Dick of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​p=5100777#​post5100777))|1963-Later Oil Slinger Washer (31067-63) ((photo by papphammar of the XLFORUM ​http://​xlforum.net/​forums/​showthread.php?​t=495298))| 
-  * Automotive PCV valves are not really made to handle the revs or air volumes ​of a Harley. While a car engine is biggerit has one piston coming down while one goes up, so not much change in internal crankcase volume, so not much breathing to be doneA Harley has two pistons and rods on one crankpin, so is one giant air compressor. +|{{:​techtalk:​ih:​elec:​generator_drive_gear_k-kh_or_xl_pic2_by_j-dvintage.jpg?​direct&​300|}}|{{:​techtalk:​ih:​engmech:​generator_drive_gear_31071-58_by_dr_dick.jpg?​direct&​300|}}|{{:​techtalk:​ih:​engmech:​oil_slinger_on_76_xlch_by_papphammar.jpg?​direct&​300|}}|
-  * Some guys have found that plumbing in a 77-78 foo-foo valve on the later model engines improves breathing +
-LINKSDiscussion on foo-foo valves and engine breathers pics etc here: +
-[[http://​xlforum.net/​forums/​showthread.php?​t=213630]]+
  
-There are other threads but this pretty much covers it all anyhow. Pretty simple but seems to cause repeated headaches for such a pesky little thing. ((Hopper from the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=518948&​highlight=wet+sumping)) 
  
 \\ \\