Sump gasket problem.

[dougal9887]

When I started tightening down the sump, the gasket started to extrude and appeared to be disintegrating. I abandoned the attempt. Here is what it looked like.

Sump gasket.

The gasket was from Burton. I used RTV silicone both sides as recommended in the Wilkins book and hadn't yet reached 10 lb ft.
So does the problem lie with the gasket, the type of compound or the technique?
I'm wondering if the RTV is too slippery allowing the gasket to be forced out.
Help!
Dougal.

[7skypilot]

There's lots on info on the Forum about 'sticking' cork gaskets to one very clean surface, letting it dry, then reassembling. The glue prevents the cork from sliding away.

Another option is to use RTV, allow it to dry on one surface and then applying to the other surface before assembling with a similar result.

Personally, I use no cork gaskets on the Twin Cam or BD engines. Cometic gaskets are used throughout. The Cometic sump gasket seems to be immortal and, combined with Kent seals at either end seems to work - I have some rusty sump bolts! Burtons sell them - I sure there are other suppliers.

Good luck!

[jono]

Did you check that your sump pan face was flat?

Probably telling you how to suck eggs but it's important that the holes have been tapped back flush with the face of the pan otherwise they bottom out on the flange of the block before the gasket is properly compressed, or else extrude the gasket in the hole locations.

I stuck the gasket and lip seals down to the block overnight with Loctite RTV (oil grade) and lightly applied the sump, just nipped enough to position the gasket and seal it to the block.

When this is set, apply a further bead to the cork face and nip the pan up just enough to form a seal. Forget torque values as you can always nip it up further after a few miles if it weeps anywhere.

Cheers

Jon

[ericbushby]

Hello Dougal,
You say that you had only tightened the screws to 10 lb/ft, but the Miles Wilkins book says 8 lb/ft and the workshop manual says 6 to 8. Maybe you overdid it. I found that my target torque of 7 was very little and still the gasket extruded considerably. Hope this helps.
Eric in Burnley
S3SE DHC

[rgh0]

I do not believe using silicone RTV sealant on cork gaskets is the correct thing to do both from the difficulties stopping the gasket extruding when you use it and also from the risk of getting the silicone into the oil system and blocking up passages. I apologize to Saint Wilkins for disagreeing with him on the use of this.

I use Loctite NO 3 Aviation Gasket cement on all the cork and paper gaskets in the engine. For the sump gaskets I apply to the block and to the sump pan side of the cork gaskets and allow it to go tacky over about 20 minutes. I then assemble the gasket and sump pan onto the block and just do up the bolts to seat the sump without significant flat gasket compression. The square section end gaskets require some compression to seat the sump on the flat gaskets. I use a very small amount of silicone just to seal the corner join of the end crank gaskets with the flat side gaskets. Loctite also make a special sticky gasket cement for sticking cork gaskets in place, I have not tried this but the Aviation gasket cement works fine for me.

I wait 24 hours and then torque the bolts to the workshop manual value. Normally no problems with gasket extrusion but I stop tightening if the gasket starts moving. I check the torque of the sump bolts after the first couple of heat cycles and after 500 kms of running to ensure none are loose. Normally no problems after that but I check the bolts after that every few years if I have the car on a hoist for other work or a service. I use hex socket head bolts as they are easier to access with a long ball headed hex key especially those bolts in the rear bearing carrier in the six bolt sump

cheers
Rohan

[dougal9887]

Thanks for all the replies. I just didn't give much thought to the job as I'd done the job a number of times in the past with no problems BUT only using RTV at the corners and probably whatever sort of Hermertite I had to hand.
I'll need get a new sump set and adjust the method!
Dougal.

[rgh0]

Hermetite is something like the Loctite aviation gasket cement - so you had it right to begin with which is why you had no problems previously

cheers
Rohan

[dougal9887]

It's particularly frustrating when you follow instructions and things go wrong. Anyway, another lesson learned.
I find I have a tube of Loctite 5922. Any opinions on this product and any special procedures.
Dougal.

[promotor]

To help stop the gasket slipping out I use small locating studs in some of the sump bolts holes. This has a number of benefits :
1) It helps get the holes lined up so that you can pass the bolts through the holes in the gaskets;
2) Stops the gaskets slipping out as you tighten the bolts. Sometimes before the sump is even touching the cork gasket the gaskets is pushed out by the half moon seals which also like to move. If you use a locating stud in every other hole you can still tighten the sump down while stopping things slipping.

If you use little studs you can use a sealant that is a little slippery and it won't matter. Having said that I use Hylomar Blue on the cylinder block side only of the cork gasket, on both sides of the half moon seals, and plenty in the corners as that's a very likely leak point.

I never do a sump without these studs now and think it just makes things that little bit easier.

I only ever go to 8lb feet, never above even if the temptation is "just one more turn for luck!

This is Fords spec for sump gaskets so it's definitely the right figure.
HTH

[dougal9887]

Sounds like good advice.
What are the pro's and con's for the cork or rubber seals that go over the oil seal carriers? The current cork gaskets seem to have the little notch that locates in the rubber type whether cork or rubber is supplied.
Dougal.

[promotor]

You can't fit rubber type seals (although I've seen people try - most likely with a resultant oil leak) to Lotus water pump covers as they are a different width (and consequently have a different groove width in the front cover), and they don't fit the rear covers that are usually found on the factory twincams. It's the Ford crossflow engines that use the later type rear seal carriers which use the rubber half moon seals.

Cork are just as good as rubber in my opinion when considering that most cars nowadays aren't doing 50,000 miles on one sump gasket!

EDIT : The notch for each type of gasket is needed. It is used lo help locate the end of the gasket in the seal carrier.

[dougal9887]

Thanks Promotor, that's me sorted on sump gaskets!
I came across a Lotus gasket set packet in my bits and peices from the late '70s and an instruction sheet stating that on no account must sealant be used on the front cover paper gasket and that it must be fitted dry due to the possibility of blocking the oil drilling for the chain lubrication. This was after following Wilkins advice to coat both sides with Wellseal! I was however aware of this drilling and kept sealant clear of the area around it. And I have since tested with compressed air. It's clear!

[john.p.clegg]

1 Studs seem like a good idea

2 Are the Cometic sump gaskets re-usable?

3 Chain lubrication hole? is it really necessary..have you seen how wet it is in the camcover..

John

[rgh0]

The crank sprocket wears far faster than the cam sprockets and I guess Lotus wanted to ensure it had as much lubrication directed onto it as possible.

cheers
Rohan