Edelbrock Heads, oil drain back hole...

[Kerry j]

I've never installed a set of Edelbrocks before so maybe this is just what they look like, but it looks like a leak waiting to happen to me. Here's a picture of one of my Edelbrock heads sitting on the 454 sideoiler stroker I'm building. As you can see, the gasket doesn't seem to line up right with that drain back channel in the intake side of the head surface.
[img][img]

Anyway, is this going to be a problem?

OK, now I guess I've got to figure out how to post a picture.....

[afret]

That oil drain hole is different from the Edelbrock heads that I've seen.  Were the very early Edelbrock heads like that with that type of drainback hole?

[Kerry j]

Wow that's completely different!

I don't know how old these heads are; I got them in a package deal when I bought the 61 Starliner a few years ago. Just got around to building the engine for it and sent these off to Barry R for the CNC treatment. He mentioned that they're made of a different material than he see's these days; OK just different and he assumed them to be early heads.

I'm thinking I'll trim the gasket and then use some "Right Stuff" to seal it and the China wall... Any thoughts?

[afret]

That should work fine to seal it.

[My427stang]

Kerry,
Sorry I didn't reply to your email, we had a big exercise last week and I was running hard.

There are a couple issues I see. 

First you need to figure out how to drop that gasket a little lower.  It lines up with the port now, but the gasket is high everywhere else, maybe try a different brand of gasket and see if it sits a better on the port or drop the gasket and trim the roof.

Second, I'd consider shaping that hole a little to make sure you have good drainback, just blend it a little so you know it'll flow and won't give a place for any gunk to build up

Third, sealing the oil drainback is simply a matter of making sure that outer wall is sealed by a gasket, and the gasket has good crush.  Once the gasket is sitting in the right place you can figure out if the gasket will seal.

I would be VERY mindful of where the RTV flows with that setup, if any pushes into the drain, it'll plug.  All the more reason to shape that hole for a nice clean return.

On heads/intakes that need some fitting of a gasket like that, don't be afraid to do what you need to do, including cutting off the locator tabs on the bottom.  Just remember, if you do that, glue the gasket to the head so it wont move.

[Kerry j]

No problem Ross, we all have lives and it sure seems like there's always plenty to keep busy; I really appreciate your input.

I tried a Victor Reinz gasket, but I didn't really look at how the ports and bolt holes lined up; I was stuck on that drain back hole. There just isn't much for the gasket to contact on the back side of the drain hole. I'm sure I inadvertently made it worse, where I had Barry mill off the Edelbrock logo. I will for sure blend the drain some to make sure it's going to drain, but when I see how thin the amount of gasket that's going to contact the head there it does cause me a little heartburn. I'll just make sure it's going to drain after the sealant is in place.

[66FAIRLANE]

Mine look the same as yours Kerry. Well they did. I opened and blended the drain as Ross described. I just used the Fel Pro gaskets that came in the full gasket set and all was good.

[ScotiaFE]

Interesting milled slot.
I would say that is an up grade compared to a stock drain hole.
You may have to fiddle around with the gaskets a bit, but the milled slot will help with the drain back. imho
I went out and had a gander at a intake and it has a relief cast in that would line up pretty good with
that milled slot on the head.
Spending a bit of time making sure they line up would work well.

[Kerry j]

OK, so I trimmed the gaskets so that they don't interfere with the drain back holes that are milled into those Edelbrock heads. That part looks fine; then I looked at the matching surface of my Blue Thunder Med Riser 8V intake manifold and there isn't any provision milled into the intake manifold like that shown on the intake Howie posted. It appears that the only drain back I would have is the thickness of the intake gasket.

The question is; am I worried about a non-issue or do I need to grind on the intake manifold and create a channel for oil to drain back?

[jayb]

I don't think you'd hurt anything by doing a little grinding on the intake.  More drainback is good; I'd do it.