Having a stupid problem sbc dart block used right stuff silicone then ultra grey can’t get intake end seal area to stop leaking silicone sticks to intake not to block when I pull it apart manifold comes off with no effort built lots off engine never had this problem has afr heads on it doesn’t look like it coming between head and block thanks for help

you don't need or want both sealants.

clean the china rail with brakekleen, apply at least a 1/4" high bead, maybe more, of the Right Stuff along the china rail and up onto the intake gasket tabs and put a dab under the gasket tabs at the rail. Install the intake, torque the bolts to 25 ft./lbs. wet finger seal the silicone at both end rails and go on with life. I would allow the silicone to cure a minimum of 24 hours before running the engine.

Done it twice like that still leaks have other other engines out there no problems driving me crazy

then you've got something else going on like a crack in the manifold or head.

Or you have a butt load of crankcase pressure!

I swear you can lift an engine that has the Right Stuff on both ends of the intake without any intake bolts in!

If you had the heads angle milled there's usually a small area of the head that wasn't milled right up where it meets the intake. It doesn't crush the head gasket there and will weep oil like crazy. The solution of course is to smear a little silicone in that area on all 4 corners/tabs of the head gaskets.
Hope that's your issue and fixes it for you...

as I already stated...

quote:

Originally posted by 1320racer:
apply at least a 1/4" high bead, maybe more, of the Right Stuff along the china rail and up onto the intake gasket tabs and put a dab under the gasket tabs at the rail.

My suggestion has nothing to do with the intake manifold or intake gasket. I'm talking about the corners of the head gasket itself.
For example, when a head is angle milled say .100"-.000".......100" is removed down by the spark plug edge of the head and zero up by the manifold edge of the head. The zero milled area is often actually now a negative number because it never got milled at all and doesn't clamp down on the head gasket any longer. Resulting in oil seeping through.
The correct fix is to remove the heads and apply sealant on both sides of the head gasket in that area. I have seen people that didn't catch this during initial assembly just remove the intake and clean the area in the valley were the head meets the block and smear a small amount of silicone along that spot. But I always worried about any of that silicone coming off and down into the valley.

Hard to believe The Right Stuff didn't stick to something. Can't imagine what would cause it to not stick to the block.

I agree with imakehp. There is your problem. I see that so much on dirt track motors that I now seal all head gaskets as he describes.

Please enlighten me how his heads and/or his head gaskets are the reason the right stuff isn’t sticking to the China rails on his dart block.

This message has been edited. Last edited by: 1320racer, March 12, 2018 08:23 PM

We had a set of head gaskets that didn't come all the way out from under the head. Be sure and get silicone all the way under the edge of the heads.

If all is correct with the part sealing surface angles and gaps, it's blow-by pushing the silicone out.....OR, is the distributor aligned when you set the intake? I set the intake, insert the distributor, then tighten the intake down.

I have a set of angle milled heads that are a bit of a nightmare as mentioned above....

Dave, don’t bother trying to explain to Mr Know It All!

quote:

Originally posted by rs72z:
We had a set of head gaskets that didn't come all the way out from under the head. Be sure and get silicone all the way under the edge of the heads.

It is either Felpro or Cometic that has this problem with my SBC. One of them does not have the little triangle piece that goes up towards the intake. They even tell you right on the package to seal that area with silicone.

Thanks for the replies we dynod this engine no leaks till put in car heads not angle milled

If the right stuff is not sticking to the China wall, the walk was contaminated some how upon assembly. Only thing that explains that.

agreed and that's where his leak is originating.


I have to pry my manifold off the china rails held with the right stuff.

Reinstalled my intake manifold a few weeks ago, using the right stuff and the method I described above. Heads have been angled milled from day 1. Started engine yesterday, no leaks, no different than any time I've installed an intake manifold over the past 4 decades using all the Permatex Ultra RTVs...blue, black and orange long before the right stiff ever existed.

at the drama...

IF the problem is because the sealers are not sticking to the rails then, if it were me, I'd roughen the rails with emory paper or other abrasive device. Then clean with an aggressive cleaner and dry before re-installing the manifold.

IF the problem is something else then there is also some good advise in this thread on where else to look for the problem.

Scott

again, until he gets the RTV/the right stuff to adhere to the china rails, there is no other talk of the cause of the leak, it's the failing silcone!