Literally, when I saw oil on the garage floor a big vein in my appeared over my left temple pumping pretty good, I figure around 40psi.

A little history, I have built a few motors going back to the late seventies and once you have oil leak out the back of the intake manifold between the manifold and block (china wall ) that is usually the last time it happens because you make damn sure that f'ing annoying thing never happens again.

Flash forward 40 or so years and many engines built with 200 junkyard blocks and not ever another leak back there.

Now I decide to build my current 427ci small block with a brand new World Motown block. The brand new block has the decks squared up and sized at the proper stock height. I got the Vic Jr intake port matched to the AFR 227 heads by AFR and mock up with the intake on looked like everthing would be fine including the rear intake gap.

So I put it together and it run fine but I have oil on the garage floor from the brand new motor. I get a oil detection kit and I can see oil coming out of rear of the intake, not to much but annoying for a new motor but I decide to wait until I take the intake off to examine the roller lifters.

So when that time comes and when I put the intake back on I use a little extra RTV black across the back wall ( I also punch a row of small holes the wall and intake for something extra to hold the RTV on ).

So I fire it up and it starts leaking right away, same as before but the oil gets on the headers and garage floor, not too much but aggravating as heil.

So I decide to let it go until the next inspection, which was last night. This time I decide to use Permatex 2, now were talking 1/4 inch bead or more along the wall. Let it cure over night and well big vein sticking out of my head right now and oil on the floor again.

I build 600HP small blocks that run perfect but I can't seem to this particular motor to stop leaking. Maybe the block is cracked back there I don't know but:

I am open to any suggestions or opinions on why this is happening

 

I fought the same leak a few motors ago. Two different manifolds mind you...both leaked at the back. To pinpoint just where I was messin up, I sealed off the rocker covers and pressurized the motor with about 40# of air and sprayed windex at the back of the manifold. Turns out I was failing to get sealer in the little gap between the head and block...

 

It's time to install a belt or electric driven evacuation pump. That is not pressure driven oil coming out.

Plan B. Razor blade as much away as you can. Then scotch bright pad and brake clean spray as clean as possible. No silicone adhesives cling to oily surfaces. Then make a oil dam using this.

http://www.permatex.com/products/aut...sket_Maker.htm

 

Permatex has a newer RTV sealant called "The Right Stuff" it is all I use on builds now. Stuff sets up really fast and grips like glue onto all surfaces I have used it on so far. I have a special gasket scraper with a carbide tool bit brazed on it to get this stuff off of parts. If you really are sure it is only at the intake end rail you should have this problem cured quickly with this product.

I will tell you one time I was chasing an oil leak on my LT-1 and it took a while to discover my oil filter mount had a crack in it, I replaced the factory one with a billet one and now use those for all my HP build-ups.

 

Solid LT1 my link is to the "The Right Stuff"

 

I had a similiar problem with my 65 442. The Edelbrock Performer was not a perfect match to the 400 block. It was slightly different than the stock intake. On the 3rd try, I ended up glueing the rubber end seal to the block, then using silicone. I let it dry overnight, and re-torqued. And I torqued down to 30 lb/ft rather than the 25 recommended by Edel. I have done a bazillion manifolds with silicone, but this one was special (in a bad way). I suggest this if you do a dry fit and notice a fittment issue.

 

Check Your oil pressure connection at back of intake. if it has oil on it where the line goes in the brass connector then thats Your leak. Probably not but worth checking.With Your experience I can't see it being the silicone leaking unless Your building up pressure inside engine. I always use vacum to pvc in valve cover just in case. Nice motor combo by the way. I would be interested in seeing pics of the build if You have any? Also in the car pics.

 

I like that idea.

 

Good old American craftsmanship and quality I would say are giving the Chinese a good run for money on who is bottom dog. Sorry don't want to tread on anyone toes but I am an one hot amigo.

The intake is what, 20 or more years old and has a design flaw I found out 10 minutes after posting this thread.

Someone PM'ed me and told me he had to plug the hole / gap the oil is leaking though, buy removing the distributor and plugging it up though the empty distributor hole because there is a design flaw with the intake and intake rail doesn't line up with the 50 year old block rail.

Sure enough I pull the distributor and shine a light from the outside and can see a 1 inch long by1/8 inch high gap that has been ruining my freshly coated $300 a pop headers and the garage floor, not to mention the stench of burning oil for years now.

Here I was blaming myself when a bunch of morons can't machine a piece of aluminum a first year apprentice could do with his eyes closed.

So for a decade I am designing electronic equipment that is doing things you can't see by the naked eye and they tell me it better work this time and then you have a bunch of no brain idiots that can't machine a piece of aluminum to fit properly for 20 some odd years. "Hey Billy Bob try and get it as close to the engineering diagram as you can, if your off by a bit and it leaks don't worry about we work for Edelbrock.

And then Vic Edelbrock has the nerve to go on TV talking about the tradition and quality manufacturing blah blah blah of his company. He is a frcken millionaire and if you think he gives a rats azz about some guy in a one car garage with one of his crappy intakes leaking oil all over the place think again.

He is getting an email tomorrow and before you say yeah right he'll be reading that I have my ways of getting things done. The first is to point out this post

 

why can't you goop it up from the outside? I'm not picturing this. And if you lay a fat bead of silicone across the back and look to see that its pushing out everywhere, i don't see how you can go wrong.

 

Hey motor head, this is a little off subject but if your like me, you like to try different things. Next build you do try the chevy dealerships rtv. that stuff is great! Its a little expensive but the best by far...VIC...

PS if you need a part number ill get it for you..

 

Ok you guy aren't getting it and never did I for years, part of the mafiold back edge on a Vic Jr does not cover the back "china wall" of the block and my my Motown block has an extra wide one. You can put 2 tubes or Permatex 2 back there and if there is no place for it to stick to it's not going to do nothing. There is a gap where they machined the intake wrong and it does not meet the "china wall"

I'll take some pic tomorrow and hopefully clear it up and also I hope the guy who told me about this tell me what to fill the gap in with.

 

Pics would be nice.
Surfaces didn't match and you missed it on assembly?
Sounds like you have to build out the manifold.

 

Same problem here....Nice powder coated intake, precision build, runs like a raped ape,....but leaks out the back. I pulled the distributor so I had more room. Then I laid a thick bead of RTV black on the gap between the intake and block.....Still leaks some,...but not that bad.

Can you post a picture of that one inch gap you found? Sounds like a trip to the machine shop may be in the future.

 

So you have a similiar problem to mine. Again, what worked for me was the combination of rubber end seal with silicone to make up for the mis-match. However, I believe my mis-match was slight.
The way I discovered the problem was comparing the 2 manifolds butt to butt. I couldn't believe my eyes when I saw the Edelbrock was clearly different.
Good luck, you will get there cuz you have fixed bigger things than this...

 

If they're this bad at casting intakes, you can imagine how bad the ProComp big and small block heads look. I bought a pair of each just to check 'em out. After I'd looked at 'em, I stored 'em at my ex-wife's house. Damned if anybody was gonna catch me with that junk!

 

I going to try and post some pics, it is in a place that you can't really see. I have put a couple of tubes of RTV black about 25-30 times over the years along the back edge and they still leaked, it appears the hole has to be filled in from the inside through the distributor hole.

Anyway I am actually happy as I could figure this out for years, I kept thinking I was building motors that ran good with no problems but can't stop a no brain oil leak that was dripping on to my floor from a brand new motor ?

Who woulda thought ol Vic was selling junk. There is a possibility the Chinese copies don't leak, the craftsmanship is so bad in Guangdong they may have fixed this leak by mistake

 

If your head explodes, try not to get any goop on the garage floor.

 

I've been posting for years that the quality of Edelbrock castings are not even close to matching up on the ports. Vic is getting really old. So at one of the last races I ask his wife to get him to sign a couple of hats for me.

For the record I first used a Weiand single plane and now a Motown single plane on my Motown block without a problem.

 

Can you get me one of those hats so I can put it under his leaky parts, don't really care if it's signed or not probably wouldn't even do a good job at catching oil.

Here's the pic, I put a flashlight at the back a directed the light at the hole. You can see the gap about an inch long and 1/16 to 1/8 inch high. And please I really don't need anyone telling me that RTV should have filled that gap as others have had the same problem and the china wall on my Motown block is actually about twice as wide as a normal OEM block and you still get this F ing gap.

I can see why it hasn't been fixed in the 20 some odd years they have been selling them, looks like a pretty tricky milling job and a first year apprentice might need about 5 minutes to fix it

PS I never use RTV around the distributor gasket just so sick and tired of this leak I put it everywhere there was a remote possibilty of a leak