old valve covers on newer heads

[jocko]

Good evening folks - quick "pcv" question - I'm interested in sticking a set of old vette valve covers on a newer gm crate engine (the holes line up - it's not a center bolt valve cover crate and the vette covers are straight hole not staggered) - but I'm trying to figure out how to have a useful PCV system... The intake manifold I'm going to add with the vette covers is an early 60's offy piece and it has the oil fill tube up front, so oil fill won't be a problem - but am concerned about building up crankcase pressure, blowing oil from the filler cap, etc etc.

Any ideas how to make this set-up work? Making a newer 350 crate look old has some nuances I hadn't thought of...

Thanks!
jocko

[markeb01]

Here's a link to how I did mine. I imagine there are other concepts that might be easier:

http://67-72chevytrucks.com/vboard/s...d.php?t=366853

I've seen where others simply use an oil fill pipe with a smog connection and a breather on top, but this arrangement won't effectively evacuate the crankcase fumes. Instead the pcv valve pulls fresh air straight from the breather. Ideally, the breather (fresh air source) should be at one end of the engine and the pcv valve should be at the other (or opposite sides).

[jocko]

that is AWESOME! Thanks very much - the design looks pretty simple and I believe I could make it - I was scratching my head wondering where I could stick a pcv valve...
Now doesn't a pcv valve have a check ball in it or something like that? Your design looks like a simple vent to the carb - and that seems like it ought to work to me! Sounds like you've had no problems with its performance. I might just give this a try - your goal was the exact same one I have. Thanks again.

[geezer#99]

Nice work Markeb01. Jocko. You can buy a breather from edelbrock or offenhauser that will bolt on in the same location. Look on ebay. Lots there.

[protrash64]

Without thinking this thru completely, couldn't a hole be drilled in the valve cover to run a pcv valve?

[markeb01]

Originally Posted by jocko

that is AWESOME! Now doesn't a pcv valve have a check ball in it or something like that?

Yes, the check ball “mostly” shuts off airflow at high manifold vacuum (idle) to avoid the effect of a vacuum leak. When manifold vacuum drops (normal driving) spring pressure inside the valve opens the check ball allowing crankcase fumes to be ingested into the intake manifold.

Originally Posted by protrash64

Without thinking this thru completely, couldn't a hole be drilled in the valve cover to run a pcv valve?

I thought about that for a while, just stick a grommet in the end wall and plug in a pcv valve, but was concerned that lacking a baffle, oil would be drawn directly into the valve under acceleration. Don’t know if it would or not, but with the arrangement on mine, the inside piece acts as a baffle, and any oil that splashes on it simply drips back into the rocker area of the head. I have experienced no oil control issues at all since installing the modified valve cover.

[jocko]

Thanks for all the replies - will look for the pieces on ebay geezer - I know the ones you're talking about and have seen many of them on old vette covers in the past. If they are the ones I'm thinking of, they could mount in the same spot, but they curve up 90 deg and would be less "stealthy" than markeb01's. I remember seeing them on some old vette race motors on fronts of valvecovers. I really like Markebo1's set up though, really hidden (and thanks for the information on the pcv valve itself). Great info, thanks for all your input.
jocko