Thread: FE Intake Oil Leak -- End Gaskets or Not?

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Thanks John. I'll definitely get another set of hands to help me.

By the way, I called Edelbrock today. After being on hold for 30 minutes I spoke with a technician. He said the reason they recommend not using the gasket is that the cork gasket tends to slide out from under the manifold over time. He said installation is tricky but even if you get it right, the cork gasket slides out from under the manifold over many duty cycles. I told him that a 1/4" bead risks air pockets like mine experienced that failed very quickly. He acknowledged that was a risk and said it is my choice. I asked him if there was a measurement for the gap where a gasket is more or less desirable. (The compressed RTV from my previous install measured at 3/32). He said there was no range where they would change their recommendation but the larger the gap, the less desirable RTV is for the install. (Somewhat contradicting himself). He did say the Right Stuff is a great substitute for the RTV.

Hopefully this helps others avoid a re-do. Thanks again!

Originally Posted by jawarner

He said installation is tricky but even if you get it right, the cork gasket slides out from under the manifold over many duty cycles.

"Factory Original Equipment", on "Millions of Ford motors", over decades! I rest my case!

I agree with you John, even on the aluminum manifold. I am not sure what about an aluminum manifold would make the cork gasket slide out any faster than the heavy cast manifold from the factory. (Maybe the way it expands and contracts?).

Even if the gasket slides out after 20-30,000 miles, that is 20-30,000 more than I was able to get out of RTV alone.

I'll be do it the original way.

Thanks again.

I've haven't used the end gaskets in years. The deck height or milled heads have
a lotto do with that. Take a punch and knurl the ends of the surfaces on the
top of the block. Maybe a little on the manifold too. I just did the block surfaces
and it work fine.Use gaskets if there's room and knurl the surfaces. If not silicone.

so i just got done installing a new engine in my truck its a fe 390 with the performer intake. my intake is warp just enough that it doesnt sit on the heads evenly... i used the gaskets that the machine shop gave me and i think it was engine pro.. they are thicker gaskets than the fel-pro... i put that copper rtv in the corners where the haynes manual says to and let the rtv set up like the tube said to. i had a slight problem with one side on the front and back gasket trying to slide into the valley area while setting my intake. by the time i was able to get the gaskets to settle where they needed to be while i set my intake on there they were staying.. i had to use my seal picks very carefully as to not rip them though.. in the past i have used the blue rtv in place of the cork gaskets and it did a good job of sealing the are but i was graceful applying more than enough to make sure it sealed. yes it looks a lil tacky for a "show car" but it gets the job done... ive done the rtv and cork set up and never had luck with it sealing completley either. although im proud to say without using fel-pro gaskets i have no leaks.. they seemed to always not be thick enough. if you would like i could get the companies name that the machine shop used for gaskets.... btw anyone know the rated horsepwer and torque at the flywheel for the 70 models of 390's with a 4 barrel?

Hello guys,

I put the engine back together using the end gaskets and the finger full method. I've put about 3 hours on the engine since and I thought I was home free. This afternoon I looked under the car and there was a puddle of oil. Before it was leaking from the driver's front. Now it is leaking from the passenger's front. What is odd is that it didn't leak at all and then once it started, it began running out of the engine fast.

Now I am lost. I've taken this apart twice now and put it back together, once with the gasket, once without. Both times I had a leak in after about 3-4 hours of use.

Does anyone think there may be another root cause of this? The leaks have both come from the front of the motor and both went from no leak to fast leak in almost no time. I am wondering if there is something about the oil galleys at the front of the heads that might cause this? Or possibly excessive crankcase pressure?

If anyone has any ideas on what to try next, I would be very appreciative. I have already spent two weekends and a couple hundred bucks for gaskets and supplies and still have a leaking motor.

(BTW, recall these are Edelbrock Performer RPM Aluminum heads and Edelbrock Performer RPM Aluminum manifold).

Thanks

Jeff

Just a shot in the dark here, so I have no idea if this is a fix for you or not.

My first pickup was a 69 F-100 with a 360 and had the eternal intake end gasket leak which drove me crazy. No matter what I did it always seeped oil out from one side or the other, and the cast iron intake was a bear to take off and put back on by myself. Went to a friend of my dad that had a garage and paid him to make it stop leaking. I got him to tell me what he did to make it seal the first time.

He had removed the intake and used a center punch to hammer in raised dimples along the flat mounting surface to "bite in to" the strips of gasket you lay in to place. His claim was the gasket design was very prone to being pushed out in the middle because of crankcase pressure, causing the ends of the gasket to pull in away from the point where the intake, heads, and block all come together. He told me in the worst cases he actually drilled small holes along the flat surface every inch or so and would stick coathanger wire in the holes and clip it off with a pair of sidecutters to leave a small barb sticking up to lock the end gasket in to place.

Thanks for the description and thoughts. Like I said, I am getting desperate and am willing to consider any and all ideas. I most certainly will try the center punch idea as I don't think it can hurt and it might really help. Before using this method when you were fighting it, could you see the end of the front and/or back gaskets pulling away? How long did it take?

The odd thing here is I can't see any visible change in the gasket's position. And the time I used only RTV, I couldn't see it move either. It is as though those front oiling holes in the heads are putting out so much pressure that the gasket or rtv just fails quickly and then there is a breach like a dam and once it starts leaking it goes from a seep to a full out stream within seconds. I've heard it is a poor design. And the intake is a real bear because you have to pull the rockers and I have adjustable valves so I have to readjust them every time. But I would think it would just seep not breach and then pour out.

I wonder if the heads have too much oil pushing through this hole and no matter what I do it will eventually fail. The no gasket (as Edelbrock and Permatex recommend) lasted 4 hours and the gasket lasted about 3 hours.

Thanks again for your input.

How well did you clean the surfaces? I clean everything with brake parts cleaner on a rag to insure proper adhesion.

I was very thorough in cleaning the surfaces. I used Permatex's Gasket Remover following by a parts cleaner and a scotch-brite pad. On the manifold, I also hosed it off and blew it out just to make sure I got all the dust and loose gasket material. (obviously I couldn't hose out the engine).

The odd thing is when pulling it apart I can't see where it failed. I'd sure like to avoid another redo on this.

thanks,

Jeff

Originally Posted by jawarner

I was very thorough in cleaning the surfaces. I used Permatex's Gasket Remover following by a parts cleaner and a scotch-brite pad. On the manifold, I also hosed it off and blew it out just to make sure I got all the dust and loose gasket material. (obviously I couldn't hose out the engine).

The odd thing is when pulling it apart I can't see where it failed. I'd sure like to avoid another redo on this.

thanks,

Jeff

I feel your pain, Jeff. I spent all day Saturday putting an Edelbrock Performer intake/carb on the 352 FE in my 66 F100. I used Edelbrock gaskets & Permatex per the instructions. When I cranked it up, the oil started running out the back and I waterjackets didn't seal well either cause there was coolant in the oil. I pulled everything off again and learned that apparently I didn't put the Permatex on thick enough to amply fill the gap. I re-cleaned all the surfaces and used Fel-pro gaskets this time with the cork ends. I glued the ends in place with Gasgacinch and used the Permatex in the corners and on the water jackets. I'll finish it up in the morning and hopefully, it will work this time! Will let you know.

Randy

Sorry to hear that Randy. That is the tough thing about the FE motor. That gap where the cork gasket goes is huge. As I wrote earlier in the thread, I spoke with both Edelbrock and Permatex, both swore that I should not use the cork. Their theory was that with a cork gasket, you have 4 surfaces that might fail. With "the Right Stuff" and no gasket you only have 2. (Intake, Cork Top, Cork Bottom, Block). When you say Permatex, which product? I used the Right Stuff.

I will say the "Right Stuff" was unbelievable sticky and I think is a good choice but I still think when I go back, I'll use the cork. I'll probably go overboard putting too much instead of too little myself. It sure is painful having to clean all those surfaces up without getting it into your motor right?

Good luck with your FE! Hope you're leak free by this time tomorrow.

Jeff

Originally Posted by jawarner

Sorry to hear that Randy. That is the tough thing about the FE motor. That gap where the cork gasket goes is huge. As I wrote earlier in the thread, I spoke with both Edelbrock and Permatex, both swore that I should not use the cork. Their theory was that with a cork gasket, you have 4 surfaces that might fail. With "the Right Stuff" and no gasket you only have 2. (Intake, Cork Top, Cork Bottom, Block). When you say Permatex, which product? I used the Right Stuff.

I will say the "Right Stuff" was unbelievable sticky and I think is a good choice but I still think when I go back, I'll use the cork. I'll probably go overboard putting too much instead of too little myself. It sure is painful having to clean all those surfaces up without getting it into your motor right?

Good luck with your FE! Hope you're leak free by this time tomorrow.

Jeff

Hey Jeff,
It worked!! Yay! This time I used a Felpro gasket set with the cork ends like I said in the previous post, I think. The side gaskets hook into the head gasket tab to hold them in place. I glued the cork ends in place with Gasgacinch and used the black Permatex Ultra to put a big glob on the corners where the cork meets the sides and around the water jackets on the intake. I torqued it down to spec and it seems to be working fine. No leaks yet and I've been driving it around a lot today. I still have a little fine tuning to do to the carb but so far, I'm pleased with the change.
Good luck on yours. Sounds like a nice car. Have you posted any pics of it?

Later,
Randy

I install a lot of FE intakes with pretty good success. But I do a lot of up front legwork first. I measure the angles on the heads/intake to be certain they are even, test fitting the intake with flat gaskets and no end seals and checking front & back, top and bottom with a feeler guage - the distributor is used as a center locator. Once I am satisfied that all surfaces are parallel and square I will use a really small amount of Motorcraft TA-31 diesel silicone - so thin its like a coat of paint - you can see through it - on the intake gaskets to glue them in place.

I use a finger to make a thin layer on the front and rear seal surfaces both block and intake - smearing it in to assure adhesion before putting a nice thick bead of the same silicone down on top of the block - no end seals - but carry a thin layer up the filled corners toward the drainback holes in the gasket. Put the intake on using the distributor to locate it and start all the bolts - don't tighten any until they're all in.

Tighten it down and remove the distributor. There will often be some squeezed out silicone in the distributor hole - clean it ou with a finger. Use a moistened finger to smooth the front and rear seal surfaces for both cosmetics and to verify a solid seal.

The TA-31 silicone is gray, looks nice, and is really oil resistant. Dries in a couple hours.

we use that TA-31 on Detroit diesels.... On the Caterpillars we use contact cement on the gaskets. Solvent removes it when the time comes to change.
These hold 90+ lbs of oil pressure sometimes with bolt gaps as far as 8inches apart.... I'd think it'd work on the intake manifold.


Another question, if crankcase pressure is the problem, could we just vent the crankcase better?

Drew