Mercruiser 188 Cylinder Head Gasket Salt vs Fresh water

52FordF2

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I picked up a maritime 302 with a broken head bolt and blown head gasket. It was received in a long block condition. I verified it could crank, first by hand then set up a starter. I got readings of #1-130psi, #2-135, #3-131, #4-~0psi, #5-143,#6-175, #7-160, #8-170 psi. Pulled the blown head.



Had the machine shop check it. They found no problems with it. They did a slight surface cut. I also got a complete set of head bolts incase it was a material problem. I'm thinking of replacing both head gaskets.

Now what I am wondering since I'll be using this in a fresh water environment and not salt, can I get away using auto head gaskets instead of marine?
How different are they?
It would be either in Kentucky or Indiana territory most of the time.

If it did get in salt water occasionally if flushed out with fresh how much could it hurt the head gaskets?


I have all other Marine parts to complete the motor.
 

Scott Danforth

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NO. You need marine gaskets for the stainless unless you run a closed cooling system
 

harleyman1975

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Engines in cars and trucks have antifreeze to prevent corrosion boats (if raw water cooled) will be more suceptable to rust hence the brass plugs, bushings and stainless head gaskets. You can get marine gaskets at auto parts store. I buy from NAPA and OREILLY all the time. Felpro is top of line in my book.
 

Scott Danforth

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Other differences, the marine circulating pumps have brass or alluminum or stainless impellers and the automotive ones have stamped steel impellers

Marine engines use brass core plugs as harleyman1975 pointed
 

Bondo

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Engines in cars and trucks have antifreeze to prevent corrosion boats (if raw water cooled) will be more suceptable to rust hence the brass plugs, bushings and stainless head gaskets. You can get marine gaskets at auto parts store. I buy from NAPA and OREILLY all the time. Felpro is top of line in my book.

Ayuh,..... Agreed,.....
 

52FordF2

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I know you probably got Chevy or another type of engine, but offhand would you know the part number for NAPA or O"Reilly 302 Ford head gasket?

I have tried looking there for Marine gaskets, not finding them. Would it cross over to the Mercruiser 188 Cyl Head Gasket: 27-75647?
 

Scott Danforth

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Ask the guy behind the counter. I buy all my gaskets from summit racing so I don't get them locally as the local places usually have to order what I want anyway.

You can look up the felpro numbers than call your local Napa and have them order the gaskets if you want
 

Bondo

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but offhand would you know the part number for NAPA

Ayuh,.... The Sierra number, available both here at iboats store, 'n at Napa is 18-3883,.....
 
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