Engine Breather tube PCV installation when using belt Drive?

[NiteOwl]

I saw a posting awhile ago that has had me pondering.

Its been stated that when you went to a belt drive system, you should route the engine breather tube down the outside of the innner primary and there is a nice piece of hardware one of the fellows on this site makes for that. One of the guys on the forum stated you shoudl place a PCV (Positive Crankase ventilation) valve on the end of the pipe to prevent dirt being sucked back in. Sounds good, but I beleive these valves only breath one way ie out, would the engine not need to breath both in and out or is this the part I am missing? Perhaps there is another source for air into the crankcase?

I am specifically thinking about the earley 40's overhead valve engine.


Bob

[vph-d]

I've just rerouted the breather hose to blow onto the drive chain, after turning off the chain oiler. Been doing this since the 70s without problems.
VPH-D

[NiteOwl]

I guess what really got me to thinking, was if the engine breaths in and out and one was ridding on a dirt road it might be advisable to have some sort of blockadge to the dust.

[Robert Luland]

This why later on when they ran it out the the case, they put a breather screen on it. Bob L

[rousseau]

this is how I did the crankcase breather on mine with an open belt drive.

[NiteOwl]

Thanks Bob, I had no idea breather screens were fitted at a later date.

[upsrod]

On '65 and up FL's and all Sportsters, the MOCO just pointed the pipe uncovered to the ground!

[T. Cotten]

Folks,

I lost count of the dirt and oil plugged breather filter gimmicks that I pulled and tossed.

Its not a "better" idea.

The motor needs to breathe.

And if the machine sits for any period of time, sumped oil makes it worse. If you have a sprocketshaft seal for a belt drive, the whole motor can fill up.

Some things the MOCO got right.

.....Cotten