Valve Covers

[orange 69]

I have a 69 with a 73 SB 400, I was wanting to buy some script Chevrolet valve covers from a member but they do not have a PCV hole in them.
Is there another way to run the PCV system, I don't want to cut a hole in the valve cover

[calvin78612]

I would like to find out too.

[geezer#99]

Here's a good write up.
http://67-72chevytrucks.com/vboard/s...d.php?t=366853

[orange 69]

Originally Posted by geezer#99

Here's a good write up.
http://67-72chevytrucks.com/vboard/s...d.php?t=366853

That's awesome

[leftybass209]

I'm glad to have read this because I had that same idea for the 69-72 steel valve covers as a way to make a stock appearing but really clean motor. Thanks for the information everyone!
Posted via Mobile Device

[DesertCat]

Originally Posted by geezer#99

Here's a good write up.
http://67-72chevytrucks.com/vboard/s...d.php?t=366853

Yes, it's a very clean design that was done very well but with all due respect, it has some drawbacks.
Two that I see... first, only one valve cover is getting the air circulating which is a small issue but still something to be considered.

Second, he has the PCV plumbed to the wrong port in the base of the carb. While this will work, the PCV port in the front of the carb base plate was designed for this "continual leak" and in fact the carburator is designed with that in mind. This is especially important if you need to go through emissions testing.

Minor details, but for those of us who are looking at doing something like this, all the facts should be known.

A couple of months ago I found some chrome script valve covers on Ebay and scooped them up last month found an old 70's vintage Edelbrock Streetmaster manifold with the oil tube provision, just got a oil tube with the PCV bung already in it from a member here.

I figure the oil tube is the safest place to draw the vacuum through and will fit breathers to the valve covers... well, sort of.

My idea #1 is to get some of those 1" valve cover spacers and drill/tap those for hose leading to maybe the base of the air cleaner (somewhat like OEM from the era) or perhaps to a hidden breather in the cowl.

Idea #2 isn't very original, actually more retro... use some Moon 90 degree breathers. While this means putting holes in the valve covers, I still like the idea.

You could also drill through an appropriate place on your intake manifold (similar to the road draft scheme Chevy did for years) just make sure whatever you do that you adequately baffle it or you will be pulling oil through the PCV. There is a fair amount of insight on all this on the HAMB forum... worth a look.

[Tinkermc]

nice thread

[midniteblues]

i picked up a set of these for my 283 and never gave the pcv a thought good info here

on a differnt note after spraying these orange whats the best way too paint the script black?

[geezer#99]

Originally Posted by DesertCat

Yes, it's a very clean design that was done very well but with all due respect, it has some drawbacks.
Two that I see... first, only one valve cover is getting the air circulating which is a small issue but still something to be considered.

Second, he has the PCV plumbed to the wrong port in the base of the carb. While this will work, the PCV port in the front of the carb base plate was designed for this "continual leak" and in fact the carburator is designed with that in mind. This is especially important if you need to go through emissions testing.

Minor details, but for those of us who are looking at doing something like this, all the facts should be known.

A couple of months ago I found some chrome script valve covers on Ebay and scooped them up last month found an old 70's vintage Edelbrock Streetmaster manifold with the oil tube provision, just got a oil tube with the PCV bung already in it from a member here.

I figure the oil tube is the safest place to draw the vacuum through and will fit breathers to the valve covers... well, sort of.

My idea #1 is to get some of those 1" valve cover spacers and drill/tap those for hose leading to maybe the base of the air cleaner (somewhat like OEM from the era) or perhaps to a hidden breather in the cowl.

Idea #2 isn't very original, actually more retro... use some Moon 90 degree breathers. While this means putting holes in the valve covers, I still like the idea.

You could also drill through an appropriate place on your intake manifold (similar to the road draft scheme Chevy did for years) just make sure whatever you do that you adequately baffle it or you will be pulling oil through the PCV. There is a fair amount of insight on all this on the HAMB forum... worth a look.

I beg to differ Desertcat on the 2 points you mention.
All v8 pcv systems have a breather on one cover and the pcv on the other. The pcv uses manifold vacuum to draw air in on the valve cover breather which mixes with the crankcase vapours and thru the pcv into the plenum of the intake to be burned with the incoming fuel. His placement of the pcv hookup is (if you flipped the carb over) the same on both ends. The backside one is generally used for power brake hookup. The front for the normal pcv. Both open to the plenum to provide full manifold vacuum. His is set up as a stealth unit. You don't want to see that hose running to the front.
It's all about running a clean looking system and enjoying the look of those uncut valvecovers.
Sorry for the rant. JMHO

[orange 69]

Thanks for all the responses