SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: babycakes on August 18, 2022, 08:29:42 PM

Title: 460 issues. Maybe head gasket?
Post by: babycakes on August 18, 2022, 08:29:42 PM
Helping a buddy out next weekend and any help is appreciated on where to start.

It?s a 460 that ran super hot ~210ish when coming down the river last summer. Figured out there was a clogged water line. Then went to run it this summer and had water in the oil. Enough to where he has to do an oil change after each trip. Any suggestions on where to start? Is changing the head gaskets as simple as just pulling off the heads and placing a new gasket on?


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Title: Re: 460 issues. Maybe head gasket?
Post by: Flusher on August 19, 2022, 09:51:00 AM


Any suggestions on where to start?

The cheapest and easiest things first.  A compression test to see the overall condition of the engine.  It wouldn't be difficult to pressure test the engine.  Also a leakdown test. 

Where else could the water be coming from?  Exhaust?

These can help you pinpoint the source before you really start tearing into the engine and spending big money.

It is better to have a direction and not just throw money at it.
Title: Re: 460 issues. Maybe head gasket?
Post by: babycakes on August 19, 2022, 10:16:56 AM
Yeah i agree on the simple starts. Is there a guide on how to compression test a motor. He recently replaced the intake manifold gasket as well and I?m thinking that may be another spot to look at to make sure it?s all sealed there


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Title: Re: 460 issues. Maybe head gasket?
Post by: Flusher on August 19, 2022, 12:59:01 PM
https://youtu.be/ovvXnd7AhiU

https://youtu.be/hGv70RyiGGc

You should be able to get loaner tools from your local chain auto parts store.
Title: Re: 460 issues. Maybe head gasket?
Post by: size60pants on August 25, 2022, 04:21:03 PM
Yeah i agree on the simple starts. Is there a guide on how to compression test a motor. He recently replaced the intake manifold gasket as well and I?m thinking that may be another spot to look at to make sure it?s all sealed there


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Yeah if you get the wrong gasket set or don?t torque the intake down right it can leak. Make sure to RTV around the water jackets. And also trim the cork for the front and back to butt up tight to the heads and RTV all the corners too.


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Title: Re: 460 issues. Maybe head gasket?
Post by: spdbk1 on November 14, 2022, 03:53:14 AM
Common problem on the 460 is the timing cover it has a area that where's thru and then let's the oil and water mix new covers about 90.00 also good time to replace the timing set
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