5.7l Engine

[FIBER]

The engine on my 1988 Searay Sorrento S23 has developped what seems to be a crack in the block. Water is leaking into the oil. It is a 5.7L Chevy. I need to know if a 5.7L automotive engine will work ( mounts, exhaust, etc...) and what is required ? Can I use the automotive engine and just have to transfer the marine components? Any help is appreciated.

[Corpus Skipper]

Water is leaking into the oil

Check the head gaskets first, that's the most likely source. Otherwise, check out this thread http://boatdesign.net/forums/showthread.php?t=650

[FIBER]

Other than disassembling the engine, what is the best way to pinpoint if the problem of water getting into the oil is from the head gasket or a crack in the block?

[atroader]

Originally Posted by FIBER

The engine on my 1988 Searay Sorrento S23 has developped what seems to be a crack in the block. Water is leaking into the oil. It is a 5.7L Chevy. I need to know if a 5.7L automotive engine will work ( mounts, exhaust, etc...) and what is required ? Can I use the automotive engine and just have to transfer the marine components? Any help is appreciated.

Yes, you can use a non-marine long block. The only thing I would be weary of is using a street cam versus the marine cam you currently have. Also, dont use a high volume oil pump if your current oil pan is 5 qts or less.

[Corpus Skipper]

Other than disassembling the engine, what is the best way to pinpoint if the problem of water getting into the oil is from the head gasket or a crack in the block?

A compression check will usually verify a bad head gasket.

[War Whoop]

Let’s see head gaskets, brass freeze plugs ,marine cam and , marine rated valves should do the conversion.

[dannobee]

Are you sure it's not a riser or exhaust manifold leaking? These are far more common than cracked blocks and blown head gaskets.

[PAR]

I'm inclined to agree with dannobee on this, as the small block Chevy engine is known for cracks from the head bolt holes to a water jacket, spark plug to exhaust valve seat on cly's 3-5 or 4-6, risers and manifolds are a common source for leaks. The wrong length bolt in the waterpump boss on the front of the motor and a bunch of other places water can be getting into the pan.

Do a leak down test on it and insure this is for sure, then a compression check (maybe you'll get lucky) Odds are you'll pull the heads for a look see (not that bad of a job really) the average back yard wrench can do this in an afternoon (take lots of pictures before and during the process, trust me)

[gonzo]

Head bolts can also leak water into the oil. They should be sealed with gasket or thread sealant. Automotive engines have several differences. For example the bearings, oil pump, pistons, valves, camshaft, gasket material, freeze plugs, all the electrics, fuel pump and more.