Venting breather to intake

[KRviator]

I'm sure I've seen this on a KR-2 somewhere along the line with a VW on the noisy end, but what might some of the downsides be to venting your crankcase breather to the intake intake? Probably before the carb unless you are sure there's no way for fuel to contaminate your oil.

Any oil mist would be burnt in the cylinder instead of the exhaust, and you wouldn't run the risk of gummed up parts causing a crankcase overpressure event, if anything, you'd always be pulling a slight vacuum in the case which may go some way to stopping an annoying leak.

I can't imagine you'd experience oil-fouled plugs unless you are venting a lot of oil, but then again, I'm not the sharpest tool in the shed when it comes to engines.

What's the brains trust opinion?

[Arie]

I dont think it will be a good idea, for three reasons.
1 : your airfilter would be greatly contaminated with oil. I remember the airfilter on the VW beetle was always an oily mess inside...not good...
2: The VW beetle was generally always right side up, If you go inverted you are going to dump a whole lot of oil into your intake...not good...
3: If lycoming thought if was a great idea they would have done so a long time ago.
Regards
Arie

[Captain_John]

I had often wondered this as well. It would probably eliminate the problems associated with the anti splat venturi installed on the exhaust pipe. I know that in the automotive world they draw vacuum from the manifold after the servo in a throttle body system. That would be hard to place on one of our engines. I have never considered installing it in the snorkel after the filter. Not a bad idea but I wonder if the oil contamination would interfere with servo operation.

CJ