Positive crankcase ventilation.

[renn.ses]

Which is better, performance wise:
Connecting the crank case ventilation to:
The air breather ( Does this help prevent blown gaskets and oil leaks. Does the vacuum help or hurt engine performance. )
or
An aftermarket crank case ventilation breather

Any info will be greatly appreciated,
renn.ses

[Dave63]

Originally Posted by renn.ses

Which is better, performance wise:
Connecting the crank case ventilation to:
The air breather ( Does this help prevent blown gaskets and oil leaks. Does the vacuum help or hurt engine performance. )
or
An aftermarket crank case ventilation breather

Any info will be greatly appreciated,
renn.ses

The purpose of ventilating it to the aircleaner, is to have venturi vacuum assist in the ventilation of the crankcase fumes. Crankcase fumes contain a small percentage of unburned fuel, or Hydrocarbons.

Venting it to the atmosphere, or a catch can, is just as good.

Dyno runs have shown slight, but noticable increases with NOT recirculating crankcase fumes through the engine, via the aircleaner.

I run mine to a vented catch can. No recirculation, but no oil on the ground. Win-Win.

[renn.ses]

Thanks. I seen aftermarket crankcase ventilation catch can breathers.
What's your thought on mounting the catch can above the oil tank and draining it to the oil tank.

renn.ses

[Dave63]

Originally Posted by renn.ses

Thanks. I seen aftermarket crankcase ventilation catch can breathers.
What's your thought on mounting the catch can above the oil tank and draining it to the oil tank.

renn.ses

You can't go higher then the venting point, or at least: shouldn't. Crankcase fumes also carry heated air, which in cold metal, creates condensation. I ran mine from the head vents (on an Evo) to a can, just below the head vent ports.





Some aircleaners/venting, just run it back into the airfilter. Honestly, if you're not looking for every once of Hp available, there's nothing wrong with running it back into the aircleaner. That way, the venturi vacuum helps draw everything back through the system, even if the line runs above the vented source. Like this one:

[renn.ses]

I hadn't thought about condensation. I like your catch can.