Exhaust Joints Sealing

topcatcustom · Post by **topcatcustom** » Fri Feb 12, 2010 12:20 pm

Found an old thread on this but wanted a fresh decision! What type of sealer am I best using on my manifolds to heads- and on the joints in the system? I have 2 joints in one manifold as it was not possible to make it in one piece, and they are quite shallow joints- about 10mm. The rest of the system has about 2" long joints.

I have steel gaskets for the manifold to heads, should I use them with silicone or something? I hate the exhaust cement stuff- it seems daft putting something that hard and brittle on, flexible has got to be better surely?!!

jefferybond · Post by **jefferybond** » Fri Feb 12, 2010 12:37 pm

The steel gaskets should be good enough on their own on the manifold to head joint. For pipe joints, clear silicone is pretty good (but be wary of poisoning catalytic converters or lambda sensors), or just use nothing if the joint is nice and tight.

I agree that the putty stuff that goes hard is pretty useless!

Jeff

kiwicar · Post by **kiwicar** » Fri Feb 12, 2010 2:04 pm

Tom with Lambda sensors you must be kidding

he is a leaky bucket man if there ever was one!!!!!!
Best regards
Ed Lud

topcatcustom · Post by **topcatcustom** » Fri Feb 12, 2010 4:43 pm

Actually Mike I am thinking about putting a sensor in- not for any bloody engine confusing units though, AFR gauge

owzat?!!!

Post by **Coops** » Fri Feb 12, 2010 4:58 pm

i use good ole silicone sealer,
leak free and if you knock the exhaust its fexible and wont crack,

bigaldart · Post by **bigaldart** » Fri Feb 12, 2010 5:24 pm

Plain old grease on exhaust joints. Carbons up and seals very quickly, in a previous life as an exhaust fitter never found anything better. Whats more you can get them apart if you need to!

Alan

mgbv8 · Post by **mgbv8** » Fri Feb 12, 2010 7:36 pm

I changed to the soft comp exhaust mani gaskets from Real Steel about 2 years ago. You can trim them and knock them about a bit more than those dimply shiny ones!
The ones on the car at present have been used 3 times now!

Only because it always seems to be Saturday night when the thing is going back together. And what do I always forget to buy??
I scuff them with a wire brush and chuck them back on. But I have now realised that I'm old and stupid and have 2 new sets in the box on the shelf now. Who's going to take bets that I will have forgotten that I bought them next time I need some?

kiwicar · Post by **kiwicar** » Fri Feb 12, 2010 7:40 pm

Hi Tom
If you are fitting an AFR gauge to the exhaust you should probably get Mr vizard's book on tuning carbs and manifolds, and a set of needle files, hours of fiddling pleasure await you, though you will probably want to fit a throttle position sensor to the primary and secondary barrels pretty soon so you can log what is going on properly, oh and a MAP sensor so you know how heavily the engine is loaded, and of cause you will need to log manifold and coolent temperature. . .

Best regards
Mike

topcatcustom · Post by **topcatcustom** » Fri Feb 12, 2010 7:50 pm

Cheers guys, Al- do you use gaskets as well on the head joints? I think I'll use grease on the big push joints, silicone on the 2 shallow ones on the manifolds as they may want to blow a bit if not sealed- Will the multi thin layer steel ones be ok for the manifold to head joints? They look like they will compress a bit.

Oh- and shut up Mike I'm not going injection!!!!!