Intake gasket droop

[cwmcobra]

I didn't have as much droop as in the pictures from your teardown, possibly because this is after 5,000 miles vs. your 15,000 and I retorqued the manifold about 2-3 times before this.

I removed the manifold last night and had the same tedious task of scraping the old gasket off. I sure stuck well in the non-critical areas The manifold was bone dry; not a drop of coolant escaped during the removal. I formed aluminum foil into the block valley to catch most of the gasket shreds, then thoroughly vacuumed the valley after removing it. I will also change the oil before firing it up again. Got the Victor Reinz gaskets (apparently none too soon, since I ordered a second set and NAPA cancelled telling me they are out of stock; local stores claim they will no longer carry them) and in a test fit find they fit the ports better than the Fel-Pros did. I'm pumped to put it back together now. Have to Helicoil a mounting hole in the head that got stripped from using too short a bolt from using it to mount the throttle cable bracket. That's all been reengineered. I've also bought a new custom carb for it and I'm adding a limited slip differential, so will be really interested to get it on the road again. I'll keep you posted on the results.

Chuck

[Tony Aprile]

Chuck

I checked out your picture of the gasket and had the same exact problem after one only one year and 2500 miles. After the second gasket failure within the next year I switched to Mr Gasket, basically the same problem.
With the VR gaskets you should be fine. Go to the VR website and go to the tab, "where to buy"

http://www.engineparts.com/pubs_detail.asp?c=1&id=95

Tony

[cwmcobra]

When you did your install with the Mr. Gasket intake set, did you still use the RTV around the front and rear water jacket ports? It was recommended when I did my build and I assume it's standard for all gaskets. Just curious about your experience.

Chuck

[Power Surge]

Unless your mating surfaces are warped, the gasket should not "droop" down like that once it's installed. If it's not in the right place, it started out like that.

There are three common things that cause that...

1- Overtorquing the intake. Can push the gasket in directions other than where you want it.

2- Using silicone or gasket sealer on intake ports. Gives the gasket a slick surface to slide out of place on.

and the biggest cause...

3- NOT using the end gaskets. I know most manufacturers tell you to not use the end gaskets and just lay a bead of silicone. The problem with this, is that most Ford intake gaskets are located by the end gaskets. The end gaskets go on first and the intake gaskets sit on top of them. If you don't use the end gaskets and just lay a bead of silicone, the intake gaskets will drop down until they bottm out on the block deck.

I really can't blame any brand of gasket. I've used all brands and all kinds over the years, and NEVER had that problem. However, I HAVE pulled intakes off motors build by someone else and seen that problem.... and everyone had no end gaskets.

Just my 2 cents.

[Tony Aprile]

Chuck
Yes I did use permatex "The Right Stuff" around all water passages, for some reason the coolent just eats away at the gaskets and over time and heat cycles, the gaskets start to distort.

After the first full season of driving the exhaust started poping in deceleration, the problem was the intake gasket was so badly distorted it developed an intake leak. I changed to another set of Felpro's.
By mid summer of the next season I developed a water leak by the thermostat housing. The coolent backed out of the intake manifold bolt right by the water passage. This time I used Mr Gasket Ultra Seal. By September of the next year I developed a water leak at the rear of the manifold as coolent was leaking past the intake bolt.

The Mr Gasket "Ultra Seal" gaskets did pretty much the same thing. They failed around the water passages but did not distort around the intake port as did the Fel-Pro.

So after another local Cobra owner called Ford for the very same reason for his 351 , the Ford tech people suggested to use Victor Reinz composite gaskets. The jury is still out but there still on the motor and where running out of choices

Tony

[cwmcobra]

Sal,

Interesting post because, as you say, everyone I've ever talked to has recommended two of your no-no's: RTV replacing the end seals and RTV around the water jacket ports. You've obviously had a lot of experience and I've had a failure doing it their way, so I'm game to use your recommendation. Any other details you can provide on the procedure? Such as:

1. Do you use the cork end seals that come with the gaskets, or the rubber ones that Ford used in their OEM engines, with the rubber pegs that fit in the holes in the end sealing surface on the block?

2. Do you use RTV or other sealant on the end seals? If so, top and bottom?

3. Do you use spray gasket adhesive to firmly locate the gaskets during installation? If so, which surfaces do you stick the gaskets to?

4. If no adhesive, you've not had any problem with the gasket slipping during the torquing of the manifold? The Victor Reinz gaskets that I have are graphite coated and seem like they might have more of a tendency to slide than others. Of course, maybe that's a good design feature that is defeated if you glue them down.

I will appreciate these and any other details that you can provide. Thanks!

Chuck

[Tony Aprile]

Sal

Look at chucks pics, I somewhat agree about using silicone around the water passages as they are more lickly to squeez out of position if over tightened.
As delivered by FORD, the crate engine had no silicone on the gaskets and the did use the end gaskets, as I still do. The Ford tech guy's now say that Felpro and Mr gasket gaskets are not long term gasket systems.

Tony

[cwmcobra]

My gaskets didn't droop in the middle like the pictures I saw from Tom's car. They were solidly in place around the center ports (and very hard to scrape off there.....). The only area of concern was on all four corners around the water jackets. I suspect the RTV had a lot to do with that. And, I did retorque a couple of times due to coolant leaks at the corners that I'm sure didn't help. It makes more sense to me now to not use the RTV at all, unless it's recommended to use a light coat on the cork end gaskets.

Chuck

[Power Surge]

Originally Posted by cwmcobra

Sal,

Interesting post because, as you say, everyone I've ever talked to has recommended two of your no-no's: RTV replacing the end seals and RTV around the water jacket ports. You've obviously had a lot of experience and I've had a failure doing it their way, so I'm game to use your recommendation. Any other details you can provide on the procedure? Such as:

1. Do you use the cork end seals that come with the gaskets, or the rubber ones that Ford used in their OEM engines, with the rubber pegs that fit in the holes in the end sealing surface on the block?

2. Do you use RTV or other sealant on the end seals? If so, top and bottom?

3. Do you use spray gasket adhesive to firmly locate the gaskets during installation? If so, which surfaces do you stick the gaskets to?

4. If no adhesive, you've not had any problem with the gasket slipping during the torquing of the manifold? The Victor Reinz gaskets that I have are graphite coated and seem like they might have more of a tendency to slide than others. Of course, maybe that's a good design feature that is defeated if you glue them down.

I will appreciate these and any other details that you can provide. Thanks!

Chuck

My answers...

1- If the motor design allows for the rubber "pegged" seals, then I prefer those. Some are rubber with lips and no pegs, those are next in preferance. Last would be cork, but I still use them.

2- For the end seals, if it's the cork style (with no self stick on one side) will use 3M yellow snot on one side to glue it to the block. Then dry on the other side to the intake. I use a dab of silicone on the corners as well.

3- I have never used spray adhesive.

4- Never had any movement issues.

Here's how I do a typical intake...

First, if using cork end seals, I will fit them to the motor. This is done by cutting the "nubs" on the ends at a taper, so they lay flat to the heads. Then remove the test fit end gasket and put a dab of silicone in the corner at the head. Then I stick the end gaskets to the block, with ether yellow 3M snot or the factory peel and stick backing. Then a second dab of silicone at the corner. Then the intake gaskets go on. I use a VERY THIN coat of Ultra Black silicone sealer around both sides of the water passages. No sealer on any intake ports. Carefully put them in place, making sure they rest properly against the end gaskets. Then drop the intake down and torque to spec.

The biggest concern is acutally putting the intake on. You MUST drop it straight down. It cannot move back and forth even the slightest bit, or you'll displace all the gaskets. If you are doing an intake install on a motor that has bolts that go straight up, make up some studs and put them in the heads to use as locating pins for dropping the intake straight on. Then pull them out and replace with bolts.

[cwmcobra]

Thanks for the detailed procedure. The end seals that came with the VR gaskets are cork with no self-sticking tape on one side. I also have cork gaskets from several Fel-Pro sets that do have the self-adhesion feature. I suppose I'd have to go to a Ford dealer for the rubber seals with the pegs. My block is drilled for the pegs.

Installing the intake manifold absolutely square is difficult on this engine because of the short coolant hose connection to the water pump. What I've done in the past is get the hose bibb installed into the hose with the intake totally off the gasket, then gently pivot the back of the manifold straight down until it contacts the gasket, then install and torque the bolts. I've had good luck with the three previous installs. All, when removed, were properly positioned. Of course, I did use a light coat of spray adhesive to hold the gaskets in place during assembly.

Chuck