Using silicone as an Exhaust sealant
 

I'm having problems sealing the downpipe to the turbo on my cosworth and after discussing this issue ith a local mechanic, he suggested using high temp silicone sealant to seal the joint

Would this work? Also, what temp does a turbo get to? @300 degC?

oh dear :cry:

a turbo will see in excess of 850 degrees C of exhaust gas

high modulous silicone sealant will and has sealed the manifold to the head even at dyno temps mate, ive seen it, done for many many years, exhaust paste is hit, one you have used it you will never go back, just dont go mad.

:cry::cry:Indeed!

Dan's right, if you have a problem getting a good seal an option is to use gun gum / exhaust paste like you use for fitting exhausts together - it seals and hardens when heated.

Did the same on mine and worked a treat.

Think you can get "Fire Gum" from places like Halfords and motor factors.

Si

we use silicone on our gt40 race engines, placed either side of the gasket

never heard of that before but i personally wouldnt use silicone on my turbo.

is the downpipe metal to metal?

i had a prob on my old frst and it turned out it had a a big o ring washer between the downpipe flange, put it metal to metal and was fine. i cant see why you would get it blowing there unless its cracked? not tight enough? or got a gasket thts not meant to be there? or wrong gasket? (i dont know if cossies have one, but im gueesing not)

didnt know that you could get stuff like that!

assumed he meant the stuff you use on the bath :cry:

wow.. i'd have thought you'd have had a very small brief fire with silicone

you learn something every day

kind of along the lines i was thinking, thought he meant like fireproof silicon lol

i do mean the smelly bath stuff guys - trust me, it wont burn, it wont melt, it wornt block anything if used in the correct amounts, ive used it on the manifold on my cosworth rally cars for years and dont use manifold gaskets either ;-)

Anyone tried a mixer tap as an external wastegate

i use it at work all the time the only thing is do not use pre cat as if it goes in to the cat it will melt its way through

pmsl, well, i used silicon on the bike throttle bodies i fitted to my old escort, and that was fine, but inlet side.

i know silicon has high heat properties, but didnt know it was THAT high! :D

i once watched a n/a cosworth engine on the dyno at 9500rpm with the headers glowing red hot, with nothing but silicone sealant on them to seal to the head, i was converted way back then.

Ive used silicon for putting exhausts together for a long time, its always spot on.

:cry:

top tip! will be using this on my chavalier then! |:)