Intake Manifold 540, HELP!
 

I have a Dart Big M block, 9.0:1 static compression, 4.500" bore x 4.25" stroke, 9.800" deck, Crane 741 hydraulic roller cam, Crane roller lifters, AFR 315 CNC heads with backcut Del West stainless intake valve, Del West inconel exhaust valves, Isky (PSI) "Tool Room" springs, Crower stainless rockers, JE forged pistons, Crower 4340 billet 6.386 rods, Crower semi-lightweight 4340NT crank, Victor Jr intake, Holley marine 850cfm 4150 carbs, MSD Pro-Billet Distributor.

The problem is in the corner where the heads meet the intake on both motors above the timming chain. I have done the intake gasket twice on each side. I am using Mr. Gasket gasket set, Black RTV Silicon ( I am allowing it to film up for about 20min before applying) , I follow the order for intake bolting and I am applying 30lbs with a torque Wrench.

It is just a tiny drip, but it pisses me off becasue my bilge is red, motor is red and everything else is clean. I can't seem to stop this. I am willing to do it one more time. Any input would be great. The gaskets come with the cork front and backs but I have been using the silicoln becasue everyone says not to use them because they are junk

Re: Intake Manifold 540, HELP!
 

I always use silicone at the front and back of the intake. A thick bead, 1/4 dia. or so. Make sure it ovelaps the intake gaskets. I always put the intake on while the silicone is still wet. No leaks there ever.

Re: Intake Manifold 540, HELP!
 

I agree with PatriYatch. I always put just a little extra on the ends where the RTV meets the intake gaskets.
From my experience, if you're waiting until the RTV "skins" over, that's the problem. I've done it that way a couple of times and it leaked. I know thats what a lot of people say you should do, but if the RTV starts to dry, it won't adhere to the manifold, which is the reason you're using the Black (Adhesive) RTV in the first place.
What you don't want to do is to have to move the manifold around alot to line up the intake bolt-holes as this will squish out the wet RTV. Try to line it up perfect as you're lowering it down. A steady set of other hands helps a bunch too.
Hope this helps.

Re: Intake Manifold 540, HELP!
 

What they said + :

A good tech tip that may help:

When you intall intake, snug bolts up to ony about 10-15ft/lbs and let sit for a good amt of time, then go back and do your sequence up to recommended torque.

This lets silicone dry only partially compressed. Then you torque down intake to final specs which then puts more pressure on the silicone.

Re: Intake Manifold 540, HELP!
 

Thanks for the suggestions, I will be giving it a try.......again. Hopefully success

Re: Intake Manifold 540, HELP!
 

Another tip, clean all gasket surfaces to the metal and then use laquer thinner on them to remove all oil. Silicone doesn't adhere to oily surfaces.

Re: Intake Manifold 540, HELP!
 

And use the RTV called great stuff or good stuff made by permatex. It is almost like a rubber epoxy when it dries,hard to clean off but you can almost use it on a rear end cover or oil pan on a car and take the bolts off after it is completely dry and it still won't leak,Smitty

Re: Intake Manifold 540, HELP!
 

Is that Monty's old boat?

Re: Intake Manifold 540, HELP!
 

Yes, I bought it last August. It was Fred's from Trick Before that.

Re: Intake Manifold 540, HELP!
 

:D :D :D

Re: Intake Manifold 540, HELP!
 

I'm running a 502 block with AFR heads and Merlin intake and have the same problem. I have resealed it twice with permatex utlra seal. I sanded the block and intake then cleaned with alcohol, then put a nice bead of sealer on then the set intake on and lightly installed bolts then next morning torqed bolts to 30lbs and it still leaks. I have about .010 clearance between intake and block now I'm thinking of milling some off the intake to fit a gasket or more silicone.

Re: Intake Manifold 540, HELP!
 

That's pretty close. Did you measure before or after tightening the manifold bolts?

Re: Intake Manifold 540, HELP!
 

Do these engine's in question not have enough crankcase ventilation ?

Re: Intake Manifold 540, HELP!
 

Be sure and use an aluminium safe silicone such as ultra black as regular silicone sweats an acid as it dries.

If you are talking water leak, use blue Hylomar on both sides of the intake gaskets. This stuff was developed by Rolls Royce for jet engines and never sets and resists corrosion from forming. I have used it on all water surface gaskets for a few years and it never leaks. It is easy to clean ff also. Started using it on all outdrive mating surfaces and they are staying corrosion free also.

It also works well for blower to intake gaskets.

http://www.hylomar-usa.com/

Permatex sells it here at most autoparts in a tube

I just found it in a spray can which makes it really easy to use.

Re: Intake Manifold 540, HELP!
 

I measured after tightening the manifold bolts.
I'm running AFR intake gaskets.

SB.... I left the dip stick out to see if oil would blow out and no oil came out.

Re: Intake Manifold 540, HELP!
 

Got basic same motor and same problem. I do not let slicone skin over before putting intake on and still had leak. One weekend at the lake I tried a temporary fix by just taking a small tube of silicone and pushing in the area where it was leaking. Stopped the leak and have yet taken the manifold off and redone gasket from over 2 years ago.