I have changed my intake manifold gasket 2 times in the past month, and both times there is a leak around the ports. Gas gets in oil, oil gets in cylinder, very nasty situation. Anyways I pulled off the intake one more time (25 mins this time) and now I want to make absolutely sure I do it right. I completely cleaned all the mating surfaces with brake cleaner, and I'm fairly certain that the surfaces are not warped. I have black RTV and Felpro gaskets.

I know to put a fat bead of RTV front and back and put manifold straight down. What I don't know is if I should put RTV, and how much, around the ports. The 1st time I didn't, and it leaked (I did torque it wrong that time though). The second time I did, and it leaked. So what should I do guys?

 

dont use rtv around the ports, just the end seals,

are the gaskets correct??

if the intake and head surface are true and clean sealing should not be an issue

are you using a torque wrench and the correct pattern when you tighten the bolts

 

It seems to me that the GM intake gaskets seal a little better than the Felpros also. MIght want to try them next time.

 

I am pretty sure the gaskets are correct, they match up with the ports and have the snap in tabs in the right place. Anybody have the part # for either the Felpros or GM? And I am using a torque wrench, tightening in 10ft lb increments inside to outside.

Anybody else?

 

use edelbrocks gasket seal it works great and you can use it around teh ports
also you should go try to get the intake resurfaced that might help...

part number from summit is EDL-9300

also make sure to put a good ammount of rtv on the back and front of teh intake ...

 

That edelbrock gaskacinch is great! My kids took the cap off it and turned it upside down in my tool box Nothing like red rubbery stickey wrenchs We use it all the time on old SBCs and I second the GM gaskets they seem to be made of higher quality material. I would give the GM gaskets a try.

 

I've used Fel Pro intake set*MS95580 twice without any problems. Maybe you should check the surfaces with a straight edge.

 

Wondering if you used rtv. I put my felpro on dry this weekend and now I am becoming worried.

 

I used black RTV before to seal the ports with no problems.

 

I only used RTV (Permatex Ultra Copper) on the end rails.

 

I put the manifold back on yesterday using the Felpro gasket (I'll get GM next time if this leaks) and RTV Black only on the front and back. I checked the surfaces with a strightedge and as far as I can tell they are straight. I just have to change the oil after work today and fire it up. I'll post how it turns out.

 

I dont know if im the only one but I have had oil leak past the block and the head before it reaches the intake. I have always had to run a beed along the block and the head up to the intake. I ruined a clutch because of an oil leak. Oil in the back in the motor is more then just a spot in the garage.

 

Well, You should use the Permatex Ultra Copper (just like Rob told you)....it is designed to tolerate higher temps than black or another one in the market....You can find it in Autozone...Then You should tighten the intake bolts following a pattern established.....Then You should leave the silicon to cure about 24 hours at least....
If you already discarded warp surfaces you will be fine...
Regards
Dochidalgo

Add: Ohhh I forgot to post this link Mr. Ken Collings courtesy
http://www.geocities.com/MotorCity/Downs/4013/ol.html

If you need the bolt pattern I'm able to send you a drawing of it

 

You may also want to make sure the gaskets are sitting flat on the heads. When I did the intake on my car all of the locating pins off of the old gaskets snaped off in the heads. If it leaks again it may be worth double checking. Also I used GM assembly adhesive p/n 12346141, It worked very well for me. Good luck

Nick

 

I already installed the intake back about a week ago, also changed the plugs and wires. Right now I just came back from driving it the first time, I'll go and smell the oil soon and see how it turned out.