I have a problem trying toget my Edlebrock 2151 intake to seal in the rear of the engine. I have taken it off at least 5 times and have carefully tried to seal it. It leaks in the back. The heads are the Edlebrock 61025. I have used Permatex 82180 Permatex Ultra Black Maximum Oil Resistance RTV Silicone Gasket Maker | Summit Racing. Any suggestions would help. The heads and the intake are both new. I have never had this problem before trying to get the intake to seal to the heads.

 

I've had good luck with "The Right Stuff" Gasket Sealer over RTV.

 

x2 on "The Right Stuff" (Tom Wolfe approves this message)

 

x3 on using the Right Stuff. Ditch the included lifter valley seals.

 

One begs the question...
Why do the gasket suppliers still make the china wall seals?
That is the first thing that hits the trash upon opening the box. Been that way 45+ years and counting.
Told ya's nothing good comes from there.
Think of all the savings of time money energy silicone injection raw material molds...wasteful.
X10 for the right stuff

 

If you haven't taken it apart yet get a bottle of die and a cheap uv flashlight. Clean it off real good with brake clean and then run it for a while. I have seen many times over the years where guys have been fooled by leaks that were actually in the front of the engine or valve covers etc and the oil always ends up at the back. Its very hard to see fresh clean oil without the die in it.

I have a set of those heads sitting on a 350 block right now. I just took a look at them and dont see anything unusual that would cause the intake not to seal.

I use either the Right Stuff or Permatex Ultra black or grey and have not had a problem.

 

Bill - Spot on.

 

[QUOTE=BillK;1598144]If you haven't taken it apart yet get a bottle of die and a cheap uv flashlight. Clean it off real good with brake clean and then run it for a while. I have seen many times over the years where guys have been fooled by leaks that were actually in the front of the engine or valve covers etc and the oil always ends up at the back. Its very hard to see fresh clean oil without the die in it.

I have a set of those heads sitting on a 350 block right now. I just took a look at them and dont see anything unusual that would cause the intake not to seal.


Good point, I will try that

 

I use Permatex Ultra Black. Never had a problem. The trick is to be sure to make the bead on the end walls tall enough - I usually have to run two beads stacked to be sure. Yeah, some squirts out. I'd rather have that than have a gap that leaks. Also be sure the RTV doesn't inadvertently get pushed out of place as you lower the intake in place.

 

Another word about intake manifold gaskets. I've never been able to successfully get the "turkey tray" intake manifold gasket to seal properly. I have to cut off the sides and dispose of the "turkey tray" part.

I would recommend the same for a novice. I probably have difficulty due to my essential tremors.

 

I've been working on these cars for over 50 year and have never had a problem sealing the factory metal gasket.

 

I'd hardly consider you a novice Joe.
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I was 50 years ago.

 

I never use those seals that come with an intake

 

Update

I sent the intake back and Edlebrock sent out a new one. I will put it on sometime this week and let you gentleman know the results

Gary

 

Where do you think it was leaking from that changing the intake will fix the issue ??

 

Even if the intake is a screw up at the rear from Edelbrock…Uktra black will seal it

there can be a 1” gap, it will fill it. this is an installation problem, not an intake or sealer problem. I reuse old Turkey trays multiple times with ultra Black on each China wall and the water ports, with some aviation shellac on the bead of the gasket..never fails. that’s a USED gasket.

what are you doing?

maybe do a dry install with the gasket and see how big the gap at the end wall is? that’ll give you an idea of the thickness of sealer needed

 

Yep

 

The Ultra black and grey is more forgiving because it does not set up as fast as the right stuff.

you have to move pretty fast to get everything laid out nice and intake on before a skin sets up with the right stuff.

 

I know that it was leaking from the back. I believe it was not possibly milled correctly. Whatever was wrong with it was not because I sealed it wrong

 

You mentioned you're using new Edelbrock heads. What head gaskets are you using? Did you have the deck milled when you had machine work done to the block?

I ask because if too much is taken off the deck or heads by the machinist it can cause intake manifold fitment issues.
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I used on the intake these gasket which Edlebrock recommended Edelbrock 7284 Edelbrock Intake Manifold Gaskets | Summit Racing

I use on the head gaskets Edelbrock 7340 Edelbrock Cylinder Head Gaskets | Summit Racing

I did not have the block deck milled since I did not have a problem with the C heads I took off and the original intake. infact I have decided that if this new intake doesnt seal properly I am going to put that original intake back on it.

 

Gary,
When you pulled the intake off the last time could you see where it was leaking in the back ? You should be able to see a "void" in the rtv or some other evidence of where the leak was. If you have not already cleaned it post a few pictures of the area across the back of the block where the intake seals.

 

Hey Bill

I have already cleaned up the RTV from the block. Yes there was a spot that was void of the RTV and that same spot was present when I pulled it before. I had an even bead of rtv in the front a back and I even had put some extra rtv on the backside of the intake. That in itself gave me pause to think the intake was not milled correctly. Trust me I was very very carefully when I put the rtv down especially after 5 times. The void spot on the rtv appeared to me in about the same location. Hopefully when I install this new one every thing will go ok. crossing my fingers. Another thing I did was to wait a couple days to cure before I started the engine. I have put on a few intakes in my lifetime and never experienced this problem

 

I simply cannot imagine what would be wrong with the intake to keep the rtv from sticking to it but you never know. Maybe some crazy impurity. I always scuff up the manifold and the block with 100 grit sandpaper and then clean it with a low voc brake clean which is mainly alcohol. Make sure whatever you are cleaning it with has no petroleum products in it.

I know theoretically they should all be the same but I really think the Ultra Grey works better than the black. Almost all of the OEMs use a grey RTV.

Hope it goes good

 

This is a followup on the intake.
So Edlebrock sent me a new intake and I very carefully installed it. I put a lot of the Ultra Black sealant on the rear and let it sit for a week before I fired it up. There appear to be no leaks so far. I probably have driven the car about 60 miles since I installetd the new intake. Edlebrock did not let me know if they found a problem with the other intake and when I called them they could give me no reason if the intake was not milled correctly or not, But in my opinion something had to be wrong with the first one. crossing my fingers the problem is resolved. Thanks for all your suggestions. Much appreciated.

Gary