SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: Maker on September 07, 2014, 08:07:59 AM

Title: Exhaust gaskets?
Post by: Maker on September 07, 2014, 08:07:59 AM

Yesterday I burnt up my exhaust manifold gaskets.  It and Olds 455 with logs   what type of gasket should I use..... stock oem car manifold gasket, header gasket or copper.   The price really isn't an issue  I just don't want to keep changing gaskets

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Title: Re: Exhaust gaskets?
Post by: fullfam1 on September 07, 2014, 08:18:42 AM

I use remflex gaskets never had a leak awesome product


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Title: Re: Exhaust gaskets?
Post by: icecreaman on September 07, 2014, 08:32:00 AM

I haven't run exhaust gaskets on a boat in years.  I use high temp silicone.  Check your manifolds, if they are excessively warped, you'll never get them to seal.

Title: Re: Exhaust gaskets?
Post by: Maker on September 07, 2014, 08:48:25 AM

The manifolds do not appear to be warped   it has the oem style gasket  with divided center port  but the logs do not have divided center ports .

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Title: Re: Exhaust gaskets?
Post by: Maker on September 07, 2014, 08:50:25 AM

My thought was it started burning the divided center port part of the gasket

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Title: Re: Exhaust gaskets?
Post by: icecreaman on September 07, 2014, 09:09:37 AM

I'd clean them good and  throw a straight edge across them just to verify they're not bowed.  Then use a quality high temp silicone like Permetex.  Do a bead around each port, let it stand 5 or 10 minutes before installing them.  Then let them dry for 24 hours before starting the motor.  See if that doesn't seal better.

Title: Re: Exhaust gaskets?
Post by: Maker on September 07, 2014, 09:16:26 AM

Ok thanks  ill have to give that try

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Title: Re: Exhaust gaskets?
Post by: vintage240zracer on September 10, 2014, 02:31:30 PM

Quote from: icecreaman on September 07, 2014, 09:09:37 AM

I'd clean them good and  throw a straight edge across them just to verify they're not bowed.  Then use a quality high temp silicone like Permetex.  Do a bead around each port, let it stand 5 or 10 minutes before installing them.  Then let them dry for 24 hours before starting the motor.  See if that doesn't seal better.

X2 -  check for being warped - especially since you've changed them 2x already

JW

Title: Re: Exhaust gaskets?
Post by: MPKardell on September 10, 2014, 02:59:41 PM

X3.  I never use exhaust manifold gaskets.  I use the Permatex Ultra Copper stuff.

Olds manifolds are notorious for warping the center manifold flanges/ports because of the siamese port.  See the attached photo of some clamp-on blocks I made to eliminate this problem.  They were pretty easy to make using just a drill press and a metal-cutting bandsaw.

Title: Re: Exhaust gaskets?
Post by: Maker on September 10, 2014, 03:07:32 PM

This will be the first time I've had to change them  but who knows how many times the Po did.  Maybe it time for headers this winter

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