intake manifold sealing problem

[1970mule]

Ok, i have heard when installing the intake manifold you just need to use the large gaskets and not the small end gaskets the cork ones, i have tried this and got a leak twice. i used that high temp rtv to seal and it does not work followed proper techniques and i got a leak. so can i use the cork gasket and will it cause a problem because when i took of the orig gasket that worked great it had the cork installed with rtv also, so is that something i can do. i know many people say not to use the cork but this will be #4 on a install and i am getting tired.?:?

 

[broncnaz]

Its really up to you if you want to use them or not personally I've always had them leak with the cork gaskets. But it sounds like it might be worht a try on your engine. I've had way better luck just using RTV.

 

[Mark]

I used a thick bead of this and no probs.

http://www.permatex.com/products/Au...uto_Permatex_the_Right_Stuff_Gasket_Maker.htm


BTW, what kind of leak? Coolant or vacuum? I ask because there is a mismatch with older 302 blocks and manifold gaskets. Are you laying a thin bead of RTV around the waterports on the side manifold gasket?

 

[d.c.parris]

use the cork gaskets. use weatherstrip adhesive to stick them to the block then use a dab of rtv on the ends be careful sitting the manafold on and torque the bolts after you run it a couple of hours re torque the bolts. i have never had a problem using this method

 

[blubuckaroo]

I had always used the cork pieces without leaks but the instructions with the Edelbrock manifold said to just use RTV (funny their gasket set came with the cork pieces anyway). The trick to either method is to clean those skinny surfaces oil free (I use Chemtool). When using the cork, stick them in place on the block with Gaskasinch and a little RTV on top and the ends. When using only RTV make sure you let it cure overnight before running it. When setting the manifold in place it is important to set it on right the first time and not slide it around. I use four guide pins made from 6" long 5/16" bolts with the heads cut off to help with that.

 

[old number 8]

If you use the cork gaskets, use a pin punch and divot the block surface across where the cork lays. This will increase the grip. RTV with cork usually makes the gasket slip when compressed. It's best to put a dab of RTV in the corners only to better seal the 3 mating parts, head, intake, block. I have typically used only silicone sealer for the end seals, but you must get the right kind. I'm not familiar with the "Great Stuff", but it may work fine. I use the silicone designed for sealing the Diesel oil pans that Ford sells. It almost acts like a urethane, in that it becomes very firm.

 

[1970mule]

ok sounds like what i was thinking and to answer " MARK" it is more of a vacuum leak, where right at the back i get a oil leak that pools right in the light diviot over the clutch housing. and i did not know you had to let it cure over night the instruction did not say that, i am sure that was my problem also. but ill use this method(cork and RTV) and see where it takes me.

 

[ogr]

I had the same problem and found this site, http://www.mustangsteve.com/intake.html. I really cleaned the block surface well and then laid a thick bead of rtv. I used guide pins and let the whole mess sit overnight. No leaks, I tried twice with the cork pieces and the general consensus is to throw them away. Good luck.

 

[1970mule]

ok sounds good.

 

[mustangtoby]

I use some hi-tach on the block to glue the cork down, then a dab of rtv on the ends. Never had problems.

 

[Pedestrian]

All of these methods work, gluing is the key for cork gaskets. Allowing the RTV to cure fully is the key for that method. Good luck.
Make sure your pcv valve is working.