Differences
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techtalk:ref:engmech04k [2020/10/03 06:05] hippysmack created |
techtalk:ref:engmech04k [2023/12/20 22:22] (current) hippysmack |
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| - | ===== Breather Valves (1957-Up) ===== | + | [[:techtalk:menu|{{ :techtalk:gototechnicalmenu.jpg|}}]] |
| + | ====== REF: Engine Mechanicals - Sub-04K ====== | ||
| + | \\ | ||
| + | ====== Breather Valves (1957-Up) ====== | ||
| See the respective sections in the Sportsterpedia for the different breather valves used on Sportsters. \\ | See the respective sections in the Sportsterpedia for the different breather valves used on Sportsters. \\ | ||
| * [[techtalk:ih:engmech07|IH Crankcase Ventilation (1957-1985)]] \\ | * [[techtalk:ih:engmech07|IH Crankcase Ventilation (1957-1985)]] \\ | ||
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| 1957-E1984 engines incorporated an oil slinger (spinning gear or washer on the generator drive gear) to separate oil from air before running to the vent tube. \\ | 1957-E1984 engines incorporated an oil slinger (spinning gear or washer on the generator drive gear) to separate oil from air before running to the vent tube. \\ | ||
| - | **1957-1976 models**: ((Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=518948&highlight=cam+chest+breather)) \\ | + | **1957-1976 models**: ((Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/74149-engine-breather-101-crankcase-vent-101?t=518948&highlight=cam+chest+breather)) \\ |
| - | There is a timed breather valve built into the oil pump drive, which vents crankcase pressure into the cam timing chest. \\ | + | There is a timed breather valve built into the oil pump drive, which vents both oil and 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 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 gear or washer on the end of the generator drive gear centrifugally separates oil from the air as it is discharged overboard. \\ | A metal gear or washer on the end of the generator drive gear centrifugally separates oil from the air as it is discharged overboard. \\ | ||
| - | |||
| The rotary breather valve on the oil pump that is timed to open on the downstroke of the pistons. ((1960 HD FSM pg 3a-15)) \\ | The rotary breather valve on the oil pump that is timed to open on the downstroke of the pistons. ((1960 HD FSM pg 3a-15)) \\ | ||
| This allows crankcase exhaust air pressure and scavenge oil in the crankcase to be expelled from the crankcase to the breather oil trap and into the gearcase. \\ | This allows crankcase exhaust air pressure and scavenge oil in the crankcase to be expelled from the crankcase to the breather oil trap and into the gearcase. \\ | ||
| The breather valve closes during piston upstroke, creating a controlled amount of vacuum in the crankcase. \\ | The breather valve closes during piston upstroke, creating a controlled amount of vacuum in the crankcase. \\ | ||
| + | **The 1952-1971** breather valve opens at 77° (ATDC) and closes 67° (ABDC). \\ | ||
| + | **The 1972-1976** breather valve opens 20°-25° (ATDC) and closes 85°-90° (ABDC), less duration than the 57-71 breather. \\ | ||
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| + | |Left is the unmodified 1/4 speed R \\ valve. Right is the 1000 stock.|R model is the left one.| | ||
| + | |{{:techtalk:ih:engmech:cc_flow_4_by_dr_dick.jpg?direct&200|}}|{{:techtalk:ih:engmech:cc_flow_5_by_dr_dick.jpg?direct&300|}}| | ||
| - | **1977-78 models only**: ((Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=518948&highlight=cam+chest+breather)) \\ | + | **1977-78 models only**: ((Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/74149-engine-breather-101-crankcase-vent-101?t=518948&highlight=cam+chest+breather)) \\ |
| The timed breather on the oil pump drive was dropped. \\ | The timed breather on the oil pump drive was dropped. \\ | ||
| - | Without the breather gear that means you less control of the oil / air density in the crankcase. | + | Without the breather gear that means you have less control of the oil / air density in the crankcase. \\ |
| An external non-return valve was plumbed into the breather vent tube sticking down from the timing cover at the generator drive. \\ | An external non-return valve was plumbed into the breather 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. \\ | This allows air out, but not in. It is sometimes referred to as the foo-foo valve. \\ | ||
| The valve is installed on the outboard side of the gearcase and inside a threaded fitting with no oil separation drain back hole. \\ | The valve is installed on the outboard side of the gearcase and inside a threaded fitting with no oil separation drain back hole. \\ | ||
| - | **1979-Early 1982 models**: ((Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=518948&highlight=cam+chest+breather)) \\ | + | **1979-Early 1982 models**: ((Hopper of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/74149-engine-breather-101-crankcase-vent-101?t=518948&highlight=cam+chest+breather)) \\ |
| The external foo-foo valve and the six-inch metal vent tube at the front of the timing cover were done away with. \\ | 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 reed valve (assembly, 26909-79A) was built inside the timing cover. \\ | Instead, a one-way reed valve (assembly, 26909-79A) was built inside the timing cover. \\ | ||
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| A breather baffle tube system was incorporated into the cam cover in the area behind the oil filter and the slinger washer is no longer used. \\ | A breather baffle tube system was incorporated into the cam cover in the area behind the oil filter and the slinger washer is no longer used. \\ | ||
| The baffle tube has a one way umbrella valve mounted into it. Crankcase exhaust (air and oil mist) is routed to the breather baffle at the front of the gearcase. \\ | The baffle tube has a one way umbrella valve mounted into it. Crankcase exhaust (air and oil mist) is routed to the breather baffle at the front of the gearcase. \\ | ||
| - | Oil is separated from the air pressure by the one-way umbrella valve. The cam cover has an oil drain back valve built into the breather valve compartment. \ | + | Oil is separated from the air pressure by the one-way umbrella valve. The cam cover has an oil drain back valve built into the breather valve compartment. \\ |
| This allows accumulated oil that gets past the valve to drain back into the gearcase through that drain hole. \\ | This allows accumulated oil that gets past the valve to drain back into the gearcase through that drain hole. \\ | ||
| The air is then routed into the rear of the air cleaner via an oil hose to the gearcase outlet. \\ | The air is then routed into the rear of the air cleaner via an oil hose to the gearcase outlet. \\ | ||
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| Previously, these bolts were just used to mount the carb and air cleaner to the heads. \\ | Previously, these bolts were just used to mount the carb and air cleaner to the heads. \\ | ||
| The new breather system uses one-way umbrella valves in the rocker boxes. \\ | The new breather system uses one-way umbrella valves in the rocker boxes. \\ | ||
| - | These exit crankcase vapors through vents in the top of the cylinder head into the carb mouth to be burnt. ((FoxsterUK of the XLFORUM http://xlforum.net/forums/showthread.php?t=518948&highlight=wet+sumping)) \\ | + | These exit crankcase vapors through vents in the top of the cylinder head into the carb mouth to be burnt. ((FoxsterUK of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/74149-engine-breather-101-crankcase-vent-101?t=518948&highlight=wet+sumping)) \\ |
| On each piston downstroke, crankcase pressure (air and oil mist) is routed up the pushrod tubes into the rocker box. \\ | On each piston downstroke, crankcase pressure (air and oil mist) is routed up the pushrod tubes into the rocker box. \\ | ||
| Collected air pressure and oil mist in each rocker box is routed up into a sealed cavity in the lower portion of the box. \\ | Collected air pressure and oil mist in each rocker box is routed up into a sealed cavity in the lower portion of the box. \\ | ||
| Line 76: | Line 83: | ||
| So the head vent also doubles as a back vent to help CC vacuum drain the sealed cavity on piston upstroke. \\ | So the head vent also doubles as a back vent to help CC vacuum drain the sealed cavity on piston upstroke. \\ | ||
| - | {{:techtalk:ref:engmech:umbrella_valve_by_phillober_labeled_by_hippysmack.jpg?direct&300|}} ((photo by Phillober of the XLFORUM, labeled by Hippysmack http://xlforum.net/forums/showthread.php?p=3345764#post3345764)) | + | {{:techtalk:ref:engmech:umbrella_valve_by_phillober_labeled_by_hippysmack.jpg?direct&300|}} ((photo by Phillober of the XLFORUM, labeled by Hippysmack https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-engine-conversions/116696-phillober-s-1250-conversion-thread-pic-heavy/page11#post2487181)) |
| {{:techtalk:evo:oil:crankcase_pressure_separation_chambe_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | {{:techtalk:evo:oil:crankcase_pressure_separation_chambe_by_hippysmack.jpg?direct&300|}} ((photo by Hippysmack)) \\ | ||
| Line 92: | Line 99: | ||
| The new bolts are the same thread size as previous. \\ | The new bolts are the same thread size as previous. \\ | ||
| But instead of a simple hex, it also has a shoulder past the hex for an O-ring to be fitted between the hex head and the air cleaner. \\ | But instead of a simple hex, it also has a shoulder past the hex for an O-ring to be fitted between the hex head and the air cleaner. \\ | ||
| - | The breathing system is functionally the same as 91-03 with the one-way umbrella valves in the rocker boxes. \\ These exit crankcase vapors through vents in the top of the cylinder head and into the carb mouth to be burnt. ((FoxsterUK of the XLFORUM http://xlforum.net/forums/showthread.php?t=518948&highlight=wet+sumping)) \\ | + | The breathing system is functionally the same as 91-03 with the one-way umbrella valves in the rocker boxes. \\ These exit crankcase vapors through vents in the top of the cylinder head and into the carb mouth to be burnt. ((FoxsterUK of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/ironhead-sportster-motorcycle-talk-1957-1985/74149-engine-breather-101-crankcase-vent-101?t=518948&highlight=wet+sumping)) \\ |
| On each piston downstroke, crankcase pressure (air and oil mist) is routed up the pushrod tubes into the rocker box. \\ | On each piston downstroke, crankcase pressure (air and oil mist) is routed up the pushrod tubes into the rocker box. \\ | ||
| Collected air pressure and oil mist in each rocker box is routed up into the breather valve unit in the lower portion of the box. \\ | Collected air pressure and oil mist in each rocker box is routed up into the breather valve unit in the lower portion of the box. \\ | ||
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| It has to open with downstrokes and close (completely) with upstrokes. \\ | It has to open with downstrokes and close (completely) with upstrokes. \\ | ||
| - | | Breather Valves ((photo by DK Custom of the XLFORUM http://xlforum.net/forums/showthread.php?t=1582019&page=11)) | View of one cut open. ((photos by Bored now of the XLFORUM, annotated by Hippysmack http://xlforum.net/forums/showthread.php?p=5761087#post5761087)) || | + | | Breather Valves ((photo by DK Custom of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-era-specific-and-model-specific/efi-sportster-motorcycle-talk-2007-and-up/145738-sportster-winter-makeover/page11?t=1582019&page=11)) | View of one cut open. ((photos by Bored now of the XLFORUM, annotated by Hippysmack https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-general-discussion-and-problems/197352-oil-cap-problems-bikers-choice-02-073/page2#post4317318)) || |
| |{{:techtalk:evo:oil:breather_valves_by_dk_custom.jpg?direct&300|}}|{{:techtalk:ref:engmech:04_up_breather_1a_by_bored_now_annotated_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:engmech:04_up_breather_2a_by_bored_now_annotated_by_hippysmack.jpg?direct&300|}}| | |{{:techtalk:evo:oil:breather_valves_by_dk_custom.jpg?direct&300|}}|{{:techtalk:ref:engmech:04_up_breather_1a_by_bored_now_annotated_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:engmech:04_up_breather_2a_by_bored_now_annotated_by_hippysmack.jpg?direct&300|}}| | ||
| - | |The mesh can become saturated with oil. ((photo by dieselvette of the XLFORUM http://xlforum.net/forums/showthread.php?t=2073932&page=28))|Oil drain hole. ((photo by dieselvette of the XLFORUM http://xlforum.net/forums/showthread.php?t=2073932&page=30))|Installed upright as shown. ((photo by dieselvette of the XLFORUM http://xlforum.net/forums/showthread.php?t=2073932&page=30))| | + | |The mesh can become saturated with oil. ((photo by dieselvette of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/197307-sportster-crankcase-pressure-engine-breathing-wetsumping-and-mods/page28?t=2073932&page=28))|Oil drain hole. ((photo by dieselvette of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/197307-sportster-crankcase-pressure-engine-breathing-wetsumping-and-mods/page28?t=2073932&page=28))|Installed upright as shown. ((photo by dieselvette of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/197307-sportster-crankcase-pressure-engine-breathing-wetsumping-and-mods/page28?t=2073932&page=28))| |
| |{{:techtalk:ref:engmech:04_up_breather_valve_1_by_dieselvette.jpg?direct&300|}}|{{:techtalk:ref:engmech:04_up_breather_valve_2_by_dieselvette.jpg?direct&300|}}|{{:techtalk:ref:engmech:04_up_breather_valve_3_by_dieselvette.jpg?direct&300|}}| | |{{:techtalk:ref:engmech:04_up_breather_valve_1_by_dieselvette.jpg?direct&300|}}|{{:techtalk:ref:engmech:04_up_breather_valve_2_by_dieselvette.jpg?direct&300|}}|{{:techtalk:ref:engmech:04_up_breather_valve_3_by_dieselvette.jpg?direct&300|}}| | ||
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