Differences
This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
techtalk:ih:engmech07 [2019/12/04 01:31] hippysmack [Sub Documents] |
techtalk:ih:engmech07 [2020/08/05 21:26] hippysmack [Sub Documents] |
||
---|---|---|---|
Line 89: | Line 89: | ||
* [[techtalk:ih:engmech07a|Timing the 76< Breather Valve]] | * [[techtalk:ih:engmech07a|Timing the 76< Breather Valve]] | ||
- | The rotary breather valve is timed to open on the downstroke of the pistons. ((1960 HD FSM pg 3a-15)) \\ | + | 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)) \\ | ||
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 closes on piston upstroke, creating vacuum in the crankcase. \\ | + | The breather valve then closes on piston upstroke, creating vacuum in the crankcase. \\ |
+ | Crankcase exhaust air from the gearcase is sent out the breather tube. \\ | ||
+ | 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)) \\ | 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)) \\ | ||
Line 101: | Line 104: | ||
This diagram shows the volume swept by piston action in a 1000cc motor. \\ | This diagram shows the volume swept by piston action in a 1000cc motor. \\ | ||
It shows how much displacement is changed from min volume (0 cubic inches) to max volume(56.2 ci more than min). \\ | It shows how much displacement is changed from min volume (0 cubic inches) to max volume(56.2 ci more than min). \\ | ||
- | {{: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)) \\ | + | {{:techtalk:ih:engmech:breather_valve_drawing_1_by_dr_dick.jpg?direct&800|}} ((drawing by Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1204854&page=3)) \\ |
There's only 1.2 cubic inches of net outward flow per revolution. \\ | There's only 1.2 cubic inches of net outward flow per revolution. \\ |