slarsen

Anyone out there figured out a way to put old style valve covers (without holes) and old style intake manifold (with oil fill tube and breather) on a 350 engine (without the breather hole casting hole at the back of the block) and still get the positive crankcase ventilation to work ?

If there is a way to do this, then I would not have to go to the trouble of building a 327 (with the draft tube hole at the back of the block) to make things look cosmetically correct......and gain a few cubic inches in the process.

65RDSTR

If its cubic inches your worried about, the 327 and 350 both have a 4 inch bore. If you want 350 cubic inches in a 327 package just take out your 3.25" crank and put in 3.5" crank.

wesmigletz

You can also get a small journal 3.75" stroke crankshaft that will fit. Speed-O-Motive is one source for the cranks. With a .030" overbore, this will give you a 383.

65nassau

I'm interested in the same question here. I have a 350 ZZ series crate engine that I may like to update with old style Valve Covers- and I think the question is here "Can you put corvette 327 valve covers on a 350" - any bolt hole mods, clamps / gasketing issues, etc.

I'm guessing yes - is a 'small block a small block no matter what' - except the PCV part ...?

Can anyone answer that before we bore, stroke, etc...?

Bill J

I did it on a 65 aluminum manifold on a 350. I drilled down thru one of the threaded bosses on the left side that are used for coil brackets or something like that. I drilled through the bottom of the manifold (off the car) and tapped in a piece of 5/16 tubing. I run a hose from the tube up to the base of the air cleaner. With everything in place you would never know unless you were looking for it. I run a stock PCV valve in the oil fill tube.

65RDSTR

The valve covers will fit fine. here is a set modified.

The intake manifold will not fit.

LabRat

I did it on my '59. I have the part numbers and pics if you want them. I used an aftermarket Performer intake and had a machine shop make the opening for the PCV valve and rubber grommet. I had a splash plate welded underneath to protect the PCV valvefrom oil. A hole was put in the front of the intake and a mid 60's oil filler tube with vented breather lets the air in the motor. The valve covers remain stock and adapters are availble to mount them. I used aluminum but then switched to steel which I like better. The bolts sent with the kit are junk, replace them with Grade 8 studs like I did and avoid a big oops. I have plenty of pics and high speed internet service so it's no big deal for me to send them. E-mail me at xxxingler46@earthlink.net. Remove the xxx from the address. (I added the xxx so a web crawlers wont harvest my address) Regards. Rick.

71zman

I put a ZZ4 in my 1960 and left the origianl Corvette valve covers. GM sells a adaptor kit to change over from the newer centerbold valve covers to the older valve covers. As for the PCV, I put a hole in the top of the cover (no on the Corvette script) and used a Mr Gasket PCV grommet. I left the oil fill cap as the breather. Click on the picture link next to name to see what it looks like.

johnoblizlo

I don't have any crankcase ventilation other than my PCV after installing Corvette script valve covers. What is going to happen to my motor??

johnoblizlo

I don't have any crankcase ventilation other than my PCV (which is in the oil fill tube installed in the intake) after installing Corvette script valve covers. What is going to happen to my motor??

Allcoupedup

John,
It could explode. Here's why: inevitably there will be some a/f mixture that blows by the cylinder rings on the compression stroke. A crankcase ventillation system either releases this combustible mixture into the air or sucks it back down through the carb to be ignited. If enough of this gas builds up you could have a small explosion. I don;t think this will be a violent explosion with shrapnel all over but something could get damaged.

Brian

Aussi-66

I have old unmodified covers on my new block, I did some relatively minor modifications to the inlet manifold to accommodate the front oil filler and behind the carb I fitted a crank case vent which uses the original oil seperator. The setup works well and looks very close to stock. I will run some photos over the week end and post them ASAP.

slarsen

Thanks for all the fantastic response.

Sounds like this is easier than I thought it would be. Now what am I going to do with my two 327 blocks ? Just kidding.

Actually the intake manifold modification described above looks like the best and neatest installation, just that it is a shame to put a hole in the back of one of the original GM manifolds.

Does Edelbrock or anyone else make an old style manifold with the oil fill tube hole ? If that is the case then maybe better to modify an Edelbrock.

The key to making the engine look like a 327 is the valve covers. The manifold and other plumbing is not so apparent.

And yes if it is cubic inches there is always the 400 small block. You just never know whats under those valve covers !

thanks much for the responses.

Hitch

slarsen, I looked into this for my pop b/c his 66 has a ZZ1 in it and he expressed a concern to put the old scripted covers on it again. Before the archieves went down, I had found a couple of people that had done it before by drilling the intake. I think someone has shown that the older Edlebrock manifolds has the oil filler tube boss but it needs to be drilled out.. Let us know how it works out b/c I'm sure that there are quite a few people out there would like to do this. If I ever have to replace my motor and get the 385 Fastburn I will be taking this route.. Dave.

JohnZ

Here's another solution - one hole on the inboard wall at the rear of the driver's side valve cover for the intake hose from the air cleaner; relatively unobtrusive, and fully functional.

tapio

John,

Do you have other pics of that setup? This looks interesting.

Thanks is advance.

tapio

JohnZ

Nope - I grabbed that photo off this forum a year or two ago; I grabbed another one that had a fitting hole drilled in the plenum area of the intake just forward of the distributor about that time too, but I can't find it.

johnoblizlo

What fills the void in the valve cover is it just a hollow fitting? Also I thought this was to allow air into the engine when you pipe it to the air cleaner don't you get a sucking affect from the intake? Wouldn't oil get sucked into the intake?

slarsen

I was visiting a guy that had a 454 short block for sale (just 2 bolt) and was discussing this particular item.

He suggested drilling a hole through the back of the block into the area under the manifold. This was in response to my concern about cutting an old original GM aluminum manifold.

I know that this is not for everyone, but is a pretty straight forward job when the intake is off.

The hose off the valve cover as per the picture is also quite a neat and effective solution. Not sure but think the hose off the valve cover should go to carb vacuum and then the oil fill tube serves as the fresh air breather. Probably would work the other way too. Think the main thing is that there is a way to get the fumes out of the crankcase.

JohnZ

The PCV system is designed so the large hose from the air cleaner to the block adapter (or to the valve cover in the pic in the above post) is the "intake" side of the system, drawing air from the "clean" side of the filter element into the crankcase. The hose (and PCV valve) from the oil fill tube to the carb is the "exhaust" side of the system, using manifold vacuum to pull the crankcase vapors (metered by the PCV valve) through the engine and into the intake to be burned with the intake charge.

There's a fine screen flame arrestor in the air cleaner base where the large hose attaches to prevent a carb backfire from propagating through the hose into the crankcase, which could cause a crankcase explosion (the mixture of hot oil vapor and blow-by gases in the crankcase is flammable).