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techtalk:ref:engmech04k [2020/10/03 06:19] hippysmack [REF: Engine Mechanicals - Sub-04G] |
techtalk:ref:engmech04k [2020/10/09 13:54] hippysmack [Breather Valves (1957-Up)] |
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| **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 http://xlforum.net/forums/showthread.php?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. \\ | ||
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| 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 http://xlforum.net/forums/showthread.php?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. \\ | ||
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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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| |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 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))| | ||
| |{{: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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