Hey guys...

I got a question: Now, I REALLY like the way the old '63-67 Corvette 327 aluminum valve covers look, and I know where I can get a good set for pretty cheap.

Now, this is the question... since these valve covers have no holes in them for either oil filling or PCV/Breather, can I still use them with the '83 block I'm rebuilding?

I have an intake manifold that does have a boss (undrilled) for a oil filler tube in the front (I'd be using this intake wether I drill it for a tube or not), and I know that up untill about 1970, thats how all sbc's were.

Can I do this with the block I have? Is it a good way to go?

 

Whether "vented" or PCV, it requires two holes: One for air in, one for air out. In the pre-PCV days, the oil filler tube cap had a steel mesh in it to "filter" the incoming air. The "out" was the road draft tube at the back of the block beside the distributor. There was a baffle bolted inside the lifter valley to reduce the amount of oil going out.

The high tube of the filler and the baffle in the valley kept oil from leaving the engine. If you just drill the boss and put a PCV valve in the hole, you're bound to suck oil up. And, you still wouldn't have the "air in" part covered.

 

Actually, I just planned on drilling the boss and using a filler tube. I didn't know that there was another vent at the back of the engine though. Was that in the intake too?

 

AA, one of the better jobs I've seen of 'retrofitting' old vc's was drilling the holes on the firewall side of the vc's so you couldn't see them. The grommets held the pcv and the breather in with no problems and it was a clean job. I always liked that option.

 

Without a baffled VC you will suck oil and get oil in your breather.

 

I was thinking of just "hiding" the PCV and breather at the back, but thats exactly what I was worried about.

 

AA you'll pick up some oil anywhere if you have no baffles, you'll pick up the mist with baffles, but if you are going to go through the effort or rear mounting them, just weld in some baffles.

The welds can even be ugly and ede can't complain cuz he won't see them.

Did I just say that out loud

 

So how would I make an "out" vent, if the filler tube up front is the "in"?

Would just the filler tube alone be enought to vent the crankcase?

 

This is what I am talking about... I have an intake that has a spot that can be drilled out to have a filler tube like this installed:

 

hmm...

 

Hmm.... I'm gonna go out on a limb and say a 305 won't have that cast into the block.

Is it nessecary for ventilation, or would the tube be enough?

 

Yup, those older motors had a baffle thing in the lifter valley at the very back, next to the dist housing; and a hole drilled into the block behind the intake next to the oil pressure sending unit that it hooked to; and a tube that went from there, down along the bell housing flange, and vented under the car. The old "road draft" tube. Didn't work very well at all but I guess it was better than nothing. As you drive, of course, there's low pressure below the car, so it would tend slightly to suck fumes out of the crankcase; then it had a push-in breather in the big oil add tube at the front, to let in replacement air. Idling, they would always sit there and smoke oil vapor and combustion products and whatnot from out of that push-in breather, and that crap would tend to build up on everything all around the front of the motor. Very nasty.

In the mid 60s, when they first added PCV, they first deleted the road-draft tube, and put in an in-line PCV valve that hooked up to the place behind the intake instead. It still used the wadded up screen push-in thing for replacement air, and the big baffle thing in the lifter valley. Didn't spew funk near as bad idling as the old system did though. Then a few years later, in 69 IIRC, they went to the closed PCV system, with the little air filter in the breather, and the PCV valve and repacement air hookups in the valve covers. But the kept the push-in oil add tube for a couple of years, and changed it to take a sealed oil cap.

You'll hate having that thing in front, if you use it as a breather.... it spews oil mist all over everything on top of the motor.

Your later model block still has that place in it. So if your intake has the big tube, you can still add oil there, if you can find one of those tubes to drill the hole for and put in. I have no idea what you could do for PCV with all of that though.

Have you considered Vette L98 valve covers?

 

That pic finally loaded.... no, I don't think a 305 has that (or any other LJ motor for that matter, IIRC it went with that change), but there may still be enough metal back there to drill something that would work, if you went about it the right way.

 

looks like my ISP isn't to good at picture hosting

 

I have thought about newer Corvette valve covers (pre-L98 perimiter bolt, same style) but its really hard to find a decent set on Ebay.

I like the LT-1/L82 valve covers too... the ones the '69 Z28 had, but a pair of those in any condition are WAY too expensive.

I really like those '67 style ones though. Would it be possible to put a PCV hole in one of them (hell, they aren't original anyway) on the side that faces the intake manifold, and then have a baffle welded in? Or would that not work?

Basically, I don't mind modifying them somewhat, but I just don't want to cut up the script on top if it can possibly be avoided.

 

Try this place, ask for Iggy. I'll bet he has some.

http://corvettehangoutfl.tripod.com/

 

Yea, thats them... perimiter bolt L98 style... Been having a hell of a time finding a set on Ebay for less than $100.

I'll see what they got at that link you put up when I get back from work tonight.

Thanks RB (again lol)