Hey guys got a quick query regarding to emissions to ensure i pass

So the issue i have is quite simple but quite a pain, i have my A15 fully worked running a redline manifold with twin 45mm webber carburetors i have my crank case ventilation running to a catch can and also have tappet/rocker cover running to catch can and no return line at all just both to the catch can and vent to atomosphere via the filter on the catch can but my issue is in regards to emmisions i need a PCV put inline from the crank case and need a return to intake manifold

Now unfortunately there is physically no chance i can run anything to the redline manifold as it only has a vacuum brake line fitting which is a -3 AN and the crank case vent pipe is massive and i have fit a -10 AN braided to the catch can so my delema is without an airbox how the hell do you run a return PCV system back into the carb's to burn off these emissions

Sigh i hate these emissions rules just let me run the catch can to atmosphere

or is it fine the way i have it as my proflow catch can actually has a quenching plate to cool hot oil vapour and turn it into a liquid so it can be collected in the base.

PCV is not just for emissions, it keeps your oil more clean than a catch can -- and people have had 52 years to solve the problem of how to use it (PCV came out in 1964)


* PCV connects to the inlet manifold
* crankcase top vent connects to inside of the air filter

Use the -3 AN connection, Tee it, with an adapter hose going up in size to fit the PCV valve. Yes, -3 is small, technically too small for a brake booster, but it works. If your rings are in good shape (not producing excess blowby) there should be no problems sharing it with the Brake Booster port. If you have forged pistons you may have too much blowby when the engine is cold

Drill a hole in the air filter and use a plastic breather hose adapter

Well with that said couldn't i merge both the feeds (as they are now) into the catch can and then plum an extraction line from the catch can to the air box no need for the PCV?

It makes complete sense and i understand why but having build essentially a race engine that i still want to be able to drive around on the street with a manifold that has no provision for PCV valve it makes it frustrating and a very ugly mess without being able to just use a catch can

* Catch can only is passive ventilation
* PCV is positive ventilation -- it makes sure the block is ventilated with fresh air, while catch can purpose is to make sure that the oil is separated out

You can have both, if you set it up right