engine build

[blazin_blazer]

I'm building a 79 350 w/882 heads, basically a stock rebuild, i have a set of script valve covers that i want to use, along w/ a '68 327 intake that has the oil filler tube up front, since these valve covers have no holes....where does the pcv valve go? some1 told me that the intake should have a place for it back around the dizzy...i don't see anywhere a pcv valve will go.

 

[pauly383]

Check the April issue of Chevy Rumble , they did it with a 1" hole saw , and a rubber grommet for PCV valve in the rear of a Aluminum intake ( EDELBROCK ) . Pretty simple if theres a nice flat spot between your carb and dizzy

Your gonna have a leaker if you don't vent that motor .

Prior to PCV valve covers , and I have one of these in a 283 on the garage floor , they used a vent at the rear top block face with a baffle from the lifter valley , and a oil fill tube on the intake .

 

[4X4HIGH]

Lots of the early 283's and 327's used a PCV valve that was located in the oil fill tube. Just source out the fill tuibe that had a PCV valve and you're good to go. Just remember that you'll need a cap that is not vented and you'll also need a breather tube from the valve cover to the air cleaner to work properly.

 

[bp71k5]

I drilled a hole in the aluminum valve covers like was mentioned. It works pretty well if you start it off on the back side to get the pilot bit through the cover and then cut a little on the front side, before going to the back side again. That way you don't gouge up the finish when it breaks through the front.

 

[blazin_blazer]

man, i gotta put a hole in my valve covers, both sides? if pcv valve in oil fill tube why does it need a hose from the valve covers, thats why i like the old script covers, cause nothing in them, looks cleaner

 

[4X4HIGH]

The old engines also had a road draft tube on the back of the engine which was near the distributor but GM stopped using that in 1968.

 

[blazin_blazer]

would that be on the intake? its a 68 model, or in the block some kinda way.

 

[4X4HIGH]

It was in the block. 1967 was the last year for the road draft tube. 1968 was the first year for the large main journal and the first year without a road draft tube.

 

[blazin_blazer]

well this is 68 327, heads have 68 yr cast in them, but its a sj bottom end, an early model 68, i do believe motor was factory, was told they used the remaining sj motors then went lj...so check any 68 engine before just assuming its a lj
you never said, if i put a pcv valve in the oil fill tube, why do i need a breather tube from the valve cover to the air cleaner and would it need 1 in each cover?

 

[4X4HIGH]

You need the breather for the system to work correctly. If you only have a PCV valve then you will create a large vacuum in the engine and start sucking oil past the rings. Without a PCV system then you'll create crankcase pressure and start blowing all the seals, IE: timing cover, rear main, valve covers, intake end seals.

 

[bp71k5]

Just checking... when I mentioned "both sides", I meant drill the 1 hole from both the inside and outside of the valve cover.