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Steven Cohn
04-23-2002, 01:28 PM
Please advise,
I'm replacing the exhaust elbows and risers on my twin closed cooled 454s The elbows and risers are on the sea water side of the system. What type of exhaust gasket sealant is best for this application? I bought a tube of Permatex Ultra Black Hi-Temp RTV Silicone Gasket Maker, but am now thinking I should be using gasket cement. Any advise?
Steven

Ranman
04-23-2002, 02:04 PM
I'm not claiming to to know much about this application, but my buddy used only Ultra-black when re-installing his Berkeley Jet drive. He used it on the bowl, transom and underneath on the intake and grate. It has held up for two years with now problems so far. For regular exhaust (such as on my snowmobile pipes) I use Ultra-copper as it has a highte heat rating. I don't think that's a big concern in your application though.

Forrest
04-23-2002, 04:21 PM
In that situation where you have raw water running through two parts are gasketed together, I would use OMC Gasket Sealer in the can (1st choice) or some other similar brush-on non-hardening sticky stuff. I probably wouldn't use a silicone or silicone-like product especially if the parts are made of aluminum.

Steven Cohn
04-24-2002, 10:05 AM
Thanks for the replies. I'm concerned about using a silicone based sealant-failure could lead to water leaking into the exhaust valves and ... I wasn't sure that silicone sealants were good for exhaust temps. BTW - The elbow and riser are cast iron (stock Cruisader). I like that technical jargon "sticky stuff". Thanks again.
Steven

RickR
04-24-2002, 01:41 PM
OMC Gasket Sealer and Permatex Hi-Tack would be good products for your application but I would use Permatex "Hylomar". I use Hylomar on most of my gaskets (including exhaust manifold to head and exhaust manifold to riser). It's high temp and will not harden. If your in a pinch you can slap Hylomar on a old gasket and reuse it :rolleyes: