Crankcase vent question
- Thread starter MikeG
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that depends, on whether your motor has persistent little oil leaks or not
if not, no
if yes, then yes putting in a one way valve in the breather line will help to lower the pressure in the crankcase,
and therefore possibly lessen or completely eliminate oil leaks from the crank into the primary and also around the cylinder base, etc
many here swear by its effectiveness, myself included
There is also the benefit of a power gain. Jim Comstock has some data on how much. So it's a twofer. Eliminate oil leaks that are endemic to a pressurized crankcase and gain a little power. All for about the price of a twelve pack of a good beer. How can you go wrong?
No there is NO repeat NO advantage to add a in-line reed valve to the std cam driven breather hose.
Reason is the design operates as a timed aperature, on the compression stroke it opens 2 small ports and on the up stroke it closes them, thus the identical function to a reed valve. The deficiency is the flow path and volume is minimal that is why they moved to open crankcase breathers in 71 and again improved in 72 which do permit the negative pressure advantage of a reed valve.
Mick
Reason is the design operates as a timed aperature, on the compression stroke it opens 2 small ports and on the up stroke it closes them, thus the identical function to a reed valve. The deficiency is the flow path and volume is minimal that is why they moved to open crankcase breathers in 71 and again improved in 72 which do permit the negative pressure advantage of a reed valve.
Mick
DogT
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That's what I think, since the breathing is already timed to exhaust the pressure, what would a valve do, especially with these tiny slots in the end of the cam.
You'd do better getting the sump breather or put a proper breather somewhere else.
Dave
69S
You'd do better getting the sump breather or put a proper breather somewhere else.
Dave
69S
swooshdave
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ML said:
I'd say that it's "identical" in that they both allow air to pass but otherwise the operation is quite a bit different. The holes in the timed breathers are so small I'd be surprised if they are efficient at all.
swooshdave said:
Check the last post in this thread. It's old. Most of these guys have probably died of old age by now but they were some heavy hitters back in the day.
http://www.eurospares.com/sucker.htm
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