Hey guys,

The car is a 1980 Camaro Z28, with an 1968 327CID vette engine (HP code), currently with about 450HP (complete spec at http://www.classiccar.co.il/camaro )

I gave up the stock air filter for a K&N 14", and I'm currently using 2 breathers on the valve covers, one instead of the one the had a hose to the air filter and the second instead of the cap.

I've heard that maybe that was not a good idea.... something about intake preasure and stuff, something about using PCV breather or just the regular ones that look like the K&N air filter.

well, I'll be glad to hear what do you think about it, what's the right combination, PCV? regular? one breather? 2? (one on each valve cover), hose from a brether ro the intake/carb? etc.

Thanks,

Lior, Israel.

pic on the engine + breathers

 

If I was you, I would use one of the header "scavenger" systems. That ventalates the crankcase by pulling the air out through the exhuast instead of the intake.

 

Header scavenger systems don't work worth a crap on a street engine. You need some serious RPM, and some serious exhaust flow (meaning at/near WOT) to get them to work.

Use the PCV. Why wouldn't you? It costs you NOTHING performance-wise. In fact, it helps to ventilate the crankcase very well during part-throttle ops, where 98% of a street car's life is spent.

And, you should have kept the stock 1980 air cleaner, that seals to the hood. It will provide colder air from the air induction hood, than an open 14" filter can. K&N makes a filter that fits the 1980 air cleaner (part number E-1500).

 

Hmm, I haven't ever heard about the need for high RPM's to get the header systems too work, maybe I need to read again. PCV through the intake isn't bad, but I kinda of read it like he didn't want to do it that way, which is why I suggested the exhuast.

 

I use a pcv valve on one side and an open breather on the other. Never had any problems.

As long as your crankcase can equalize pressure with the atmosphere and effectively vent, you shouldn't have any problems. I have seen two pcv's used before, it actually created a vacuum inside the engine and made a weird noise.

If you're running a big cam on the street, I'd just run two open breathers; it's not worth sacrificing vacuum for PCV; you need it for the brakes.

I dealt with a 327 once that had a vent in the back of the block that came from the lifter valley. I routed a hose from it to the air cleaner, which supplied the PCV (positive crankcase ventilation).