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techtalk:ref:engmech04 [2020/10/06 23:20] hippysmack [Sub Documents] |
techtalk:ref:engmech04 [2020/10/07 03:58] hippysmack [1986-1990 Engine Specifics] |
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At that point, the tiny hole is a slight air (atmosphere) intake hole. \\ | At that point, the tiny hole is a slight air (atmosphere) intake hole. \\ | ||
- | The crankcase air pushes past each breather valve and exits through the heads. \\ | + | The crankcase air pushes past the breather valve and exits the engine out the breather vent (which is factory plumbed into the air cleaner backing plate). \\ |
- | A hole in each head connects the path from the outlet of the breather vent to atmosphere. \\ | + | |
- | A hollow bolt installed into each head passes the air into the air cleaner backing plate. \\ | + | {{:techtalk:evo:engmech:86-90_cc_pressure_drawing_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) {{:techtalk:evo:engmech:86-90_engine_crankcase_breathing_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) |
==== 1991-2003 Engine Specifics ==== | ==== 1991-2003 Engine Specifics ==== | ||
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At that point, the tiny hole is a slight air (atmosphere) intake hole. \\ | At that point, the tiny hole is a slight air (atmosphere) intake hole. \\ | ||
- | The crankcase air pushes past each breather valve and exits the engine out the breather vent (which is factory plumbed into the air cleaner backing plate). \\ | + | The crankcase air pushes past each breather valve and exits through the heads. \\ |
+ | A hole in each head connects the path from the outlet of the breather vent to atmosphere. \\ | ||
+ | A hollow bolt installed into each head passes the air into the air cleaner backing plate. \\ | ||
+ | |||
+ | {{:techtalk:evo:engmech:91_and_up_cc_pressure_drawing_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) {{:techtalk:evo:engmech:91-up_engine_crankcase_breathing_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) | ||
==== 2004-Up Engine Specifics ==== | ==== 2004-Up Engine Specifics ==== | ||
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===== Sub Documents ===== | ===== Sub Documents ===== | ||
* [[techtalk:ref:engmech04k|Breather Valves (1957-Up)]] (list of breather valve changes) | * [[techtalk:ref:engmech04k|Breather Valves (1957-Up)]] (list of breather valve changes) | ||
+ | * [[techtalk:ref:engmech04j|Further Study of Evo Sportster Breather Valves]] | ||
* [[techtalk:ref:engmech05|Breather Venting / Relocation]] (list of breathing mods and aftermarket breathers) | * [[techtalk:ref:engmech05|Breather Venting / Relocation]] (list of breathing mods and aftermarket breathers) | ||
* [[techtalk:ref:engmech04l|Head Vents vs Cam Chest Vent]] | * [[techtalk:ref:engmech04l|Head Vents vs Cam Chest Vent]] | ||
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* [[techtalk:ref:engmech04m|Why Oil Pukes Out the Breather]] | * [[techtalk:ref:engmech04m|Why Oil Pukes Out the Breather]] | ||
- | ==== Symptoms of Breather problems ==== | + | ==== Symptoms of Breather Valve Problems ==== |
**The most notable signs of breather valve problems include weeping / leaking gaskets or blown gaskets / seals**. \\ | **The most notable signs of breather valve problems include weeping / leaking gaskets or blown gaskets / seals**. \\ | ||
- | 77-E82 breather valves can get drudged in old thickened oil and not open/close properly. \\ | ||
L82-up rubber umbrella(s) get hard and if they don't flex well enough, they'll allow the engine to fully inhaler and exhale on every stroke uncontrolled. \\ | L82-up rubber umbrella(s) get hard and if they don't flex well enough, they'll allow the engine to fully inhaler and exhale on every stroke uncontrolled. \\ | ||
Stopped up breather valves won't allow the engine to breath well and can create excess vacuum and implode gaskets. \\ | Stopped up breather valves won't allow the engine to breath well and can create excess vacuum and implode gaskets. \\ | ||
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If the engine is not at operating temp before checking the oil level, you'll end up adding too much oil to the system. \\ | If the engine is not at operating temp before checking the oil level, you'll end up adding too much oil to the system. \\ | ||
Blowing oil out the vent/aircleaner during high sustained RPM may be high crankcase pressure or poor oil scavenging. \\ | Blowing oil out the vent/aircleaner during high sustained RPM may be high crankcase pressure or poor oil scavenging. \\ | ||
- | [[techtalk:ref:oil10#wet_sumping|Click here]] to read the full article on wetsumping in the REF section of the Sportsterpedia. \\ | + | Also see the full article on wetsumping in the sub documents above. \\ |
====== Crankcase Pressure ====== | ====== Crankcase Pressure ====== |