Intake Gaskets

tcrist · #1 (**permalink**) 03-29-2013, 06:55 PM

I am sure that this has bee beaten to death but for the life of me I can't seem to find any info.

351W, GTP-40 heads, Edelbrock intake.

What is the correct intake gasket. Mine seem to keep leaking if I hit it hard at all.

Hit it fairly hard and then on deceleration exhaust started crackeling and did not want to idle.

If I spray starting fluid on the sides of the intake the rpm's raise so I know that it is leaking. More around 7 & 8 but a bit around 2 & 3 also.

Side intake gaskets only, front and rear are holding up. Have had two sets of FelPro on it with the same issue. Torque was correct and checked after a couple of heat cycles.

I am starting to think that maybe the angle between the intake and the heads are not correct.

Any ideas?

ERA Chas · #2 (**permalink**) 03-29-2013, 07:28 PM

Quote:

Originally Posted by tcrist

I am starting to think that maybe the angle between the intake and the heads are not correct.

Any ideas?

That's very possible. Were the decks ever cut? The intake?
Call Brent and ask what he uses for leakproof gaskets on SBF. You may have coolant attacking a crappy gasket PLUS the mismatch...

blykins · #3 (**permalink**) 03-29-2013, 07:33 PM

It's possible that you have an angle mismatch, but if you're using felpro printoseals, I would try something else. I like mr gasket, cometic, sce, etc...any plain gasket that fits the port without the silicone around the ports.

tcrist · #4 (**permalink**) 03-29-2013, 08:07 PM

I'll try those Brent, thanks a bunch.

menace1 · #5 (**permalink**) 03-29-2013, 09:37 PM

I used Edelbrock 1220 intake set that is antifreeze resistant. Also used a Hi temp sealant called "The Right Stuff" and applied it to the front and rear of the intake ends with an extra dab on the corners where the intake meets the heads. It comes in the form of a caulk that is also resistant to antifreeze and hi temps. THE CAULK IS USED IN PLACE OF THE END GASKETS...
To make the installation even easier try installing intake studs about 2 1/2 inches long on the 4 corners of the heads and drop the manifold spot on to the engine.

vector1 · #6 (**permalink**) 03-30-2013, 07:03 AM

try the fms m-9439-zp, they are for the z head but fit my 205's and should work on your gt40's. they are really cometic in a fms package, nice gaskets and cheaper than buying cometic i think.

i'd also suggest installing the gaskets on the heads with sealer around the ports, set the intake on and let the sealer set up, pull the intake and check for gasket alignment and then install the intake with appropriate sealer placement if desired.

olddog · #7 (**permalink**) 03-30-2013, 11:17 AM

With the intake off, make certain that you can screw the intake bolts all the way into the head. This was my problem. The four ends would not turn all the way in.

On my Edl heads all four ends, they did not use a bottom tap. With the bolts torqued, I could slide 0.003 feeler gauge under the head of the bolts. I had to rip out the heli-coils, run a tap down, and put in new heli-coils.

I used Victor Rienze (sp?) gaskets. They have a layer of metal in them and will not deform like others. I got them at NAPA.

I went the extra mile. I used carbon steel grade 8 studs instead of bolts. I used a stainless steel washer and nut. After a few heat cycles, I re-torqued the nuts. Then I installed stainless steel acorn nuts. The acorn nut acts like a jam nut, and covers the studs for aesthetics. It looks great. You do have to pay attention to the stud length when you install them. I used lock tight on the studs going into the heads. Nothing can move on its own, now. No problems since (4-5 yrs ago).

Rick Parker · #8 (**permalink**) 04-04-2013, 10:25 AM

Olddog: Next time consider shortening the bolts .003 or using a little thicker washer. Save a lot of effort??

madmaxx · #9 (**permalink**) 04-04-2013, 01:33 PM

ROFLMFAO!!!!!!!!!!!!!!!!

, KISS, keep it simple stupid.

Quote:

Originally Posted by Rick Parker

Olddog: Next time consider shortening the bolts .003 or using a little thicker washer. Save a lot of effort??

olddog · #10 (**permalink**) 04-04-2013, 04:12 PM

Quote:

Originally Posted by Rick Parker

Olddog: Next time consider shortening the bolts .003 or using a little thicker washer. Save a lot of effort??

The threads tapered and they started not turning free about 3-4 threads before they actually locked up at full torque 20-25 lb-ft (what ever the spec is), as I remember. I would have had to take about 4 threads off to get an accurate torque. Being an aluminum head, I was a concerned about not having enough threads if I shortened them that much. I would have gone that route if it had been cast iron.

All the threads on this forum about having to re-toque the bolts and gasket failures had me wanting studs. The torque spec was pretty high for that sized bolt, and aluminum leaves me nervous anyways. So I decided to over kill the hell out of it. I tend to be obsessive on doing things right, and not having to do it over. Looks great too.