The 'E' Type Forum

I’m replacing the inlet manifold gasket.

The removed one seems to have some kind of sealant on it.

Does anyone have a recommendation of what type of sealant to use?

Should it be used on one or both sides?

This is for a 1970 S2 2+2.

Thanks

Soooo after posting this the “similar topics” part came up with much better results than my forum searches (I was too focused on the inlet manifold, not general gaskets).

Recommendations on the forums include:

Blue Hylomar
Aerograde Hylomar
Wellseal
Three Bond 1215

With “Hylomar” being mentioned he most, I assume blue.

Am I correct it should be applied by both sides of the gasket?

You're trying to stop water going into the inlet of the carbs. The best choice is a silicone sealant.

Thanks for the answer. You really think better than the other sealants?

Couldn’t you also say the same about the head gasket but I’d be surprised if silicone is used there by many people.

Just A thought. My manifold was warped . no gasket or sealant would work . My new engine ingested a liter of coolant. After two tries , I gave up and had a machinist check it . Yup ,warped and pitted. Now machined flat new gasket and sealant called " The right stuff " No problems now.
Regards,
Keith

You're looking to prevent coolant entering the induction path. The inlet manifold sees water at radiator temperature and pressure. Silicone is a good sealant for this application. We put a smear of it around all the water passage holes on both sides of the gasket. As Keith says, if your manifold is warped or badly corroded nothing will make it seal.

I agree silicone would not be a good choice for a head gasket. It sees cylinder detonation pressures and temperatures and is torqued down. Silicone wouldn't add anything to this and it is not something you want in your oil passages or combustion chambers.

RTV silicone is not fuelproof, ergo use on the intake side is arguable. Hylomar or Hermetite would work for coolant and fuel.

Everything under the sun can be argued Peter, if you have a mind to. And just about no sealant is fuel proof, as I discovered when I tried to stop my SNGB 3.8 fuel pump from leaking a few years ago.

The water is pressurised and at 90*C. The fuel is a vapour and at below atmospheric pressure or it wouldn't go into the cylinders. Silicone is a good choice. I'm sure that you could use something else. Or nothing. I suspect that it actually doesn't matter that much, but with using silicone our inlet manifolds don't leak coolant enough to make our customers complain.

Thanks Keith, Andrew and Peter all very useful. I’ll give her hermetite a go.

Keith - glad you got it sealed. Those sorts of issues can often take a while to do because it’s not such as small job.

I remember the smell of Red Hermetite, but I don't think you can get it any more. If you want a semi-hardening sealant try Loctite 515. We use this on the sump and timing chain cover gaskets. Works well there.

abowie wrote: ↑

Sun Aug 04, 2019 8:53 am

Everything under the sun can be argued Peter, if you have a mind to. And just about no sealant is fuel proof, as I discovered when I tried to stop my SNGB 3.8 fuel pump from leaking a few years ago.

I agree Andrew, which is why I only said ‘arguable’. As gasket dressing it’s OK as the fuel should never reach it. It’s different when used on metallic fittings in direct contact with liquid, like fuel banjos or taps etc. In those cases it swells and loses adhesion and if used to seal a damaged surface it will typically starts to weep and/or detach as ‘worms’. Thst’s why there’s always a contraindication on the packaging about RTV and fuel.