Intake manifold gasket ?

[luke-ao]

Are you supposed to use silicon on the little front and rear gasket pieces?

[sargentrs]

Personally, I'll never use a gasket there again. I've had too many slide out on me and start leaking. Just lay a smooth round consistent 1/4" bead of RTV dead center of the block gasket surface with a nice heavy bead perpendicular on the ends where the heads meet the block. Allow it set till still barely tacky. Then carefully set the intake straight down over it. I use long threaded rods screwed into the threads on the ends as a guide. Install the other bolts snugly. Remove rods and install bolts one at a time. Tighten gently all the way around in the suggested cross pattern, then again snugly, then again tight, then torque to spec. Once everything is installed, run till engine reaches operating temperature and torque again.

[luke-ao]

Yep, mine just worked it's way out the back last night and leaking like mad. I dont remember if I used any RTV or not but it doesn't look like it. I guess I know what I'm doing tomorrow.
What RTV do you use?

[kostiuk]

Just what Randy said. I just did mine and used Right Stuff, it is awesome but hard to get back off.
Kevin K.

[luke-ao]

Got the repair done yesterday, still waiting for the RTV to fully cure. I'm a dumb-ass, I reread my Edlebrock intake install instructions and they also said not to use the front and rear gaskets, even the instructions on the RTV said it was good to replace the front and rear intake gaskets.

This build has had the break-in oil change done, the first 1K oil change and I'm about 1700 miles into the next (I'll go ahead and change it now since I had the intake off) I ran into something strange after I pulled the intake (see pictures) it was only on the passenger side front portion of the oil galley. The sludge was puffy and smooth with a little bit of filings like you see in your first couple of oil changes on a new engine. I'm just trying to figure out what it is, as there was quite a bit, may be a table spoon or more. The only thing I can think of is maybe it's assembly lube or something(?)

The build was immaculately clean when I assembled it, so I was a little startled when I opened it up.

New 302 sludge a.JPG

New 302 sludge b.JPG

[sparky72]

Hmm. Maybe it’s some exhaust leaking from the crossover port and mixing with some oil in the galley?

[luke-ao]

Cross over port?

[cep62]

Do you have a stock intake , that has a heat shield riveted to the bottom?

If that wasn't removed when cleaning that could be a source of the sludge. :hmm:

[luke-ao]

No it's a brand new Edlebrock intake

[sparky72]

Cross over port?

The original iron heads have a port on each head which directs some exhaust gases from the front of one head, through the intake, to the back of the other head. In theory this helps get everything to temp sooner and helps the engine run better when it’s cold and just started.

The Edelbrock Performer RPM intake doesn’t have that crossover pathway and so the crossover port on the heads have to be blocked off when using it. Some folks do this with epoxy, some use a thin piece of metal under the gasket, etc. If using a regular Performer intake, it’s not a concern because it has that crossover passage in the intake.

I’m wondering if perhaps some exhaust is leaking from the crossover port on the head and is mixing with the oil in the galley, producing sludge. Just a thought.

[luke-ao]

Is this the cross over?

Edlebrock Intake.PNG

[sparky72]

Is this the cross over?

Edlebrock Intake.PNG

This photo shows aluminum heads which omit the exhaust crossover port entirely. The gasket has provisions for the crossover port, though, and you can see how there’s nothing but solid aluminum behind it. That’s where the ports are on iron heads.

[luke-ao]

So is there anyway to test for an internal exhaust leak?