5.7 Rebuild - Automotive Motor?

[T_Bone17]

I have a 2000 Super Air with the PCM 5.7 that I am in the process of rebuilding. The motor seemed to be getting a little worn out, 600 hours on the clock, and also developed an oil leak that was getting slightly worse every year.

I am sure I will have some questions along the way, and am hoping to use this thread as a means to gather useful information.

Firstly, as I am pulling the motor apart, I am wondering if it had been previously swapped with an "automotive motor"

I did some research on the differences, and what I came up with was that the marine motors (long block) only have a few minor differences. Brass freeze plugs, non steel head gasket (stainless?) baffle in the oil pan.

The freeze plugs and head gasket, are steel, or at least have enough iron content to be magnetic.

My main concern is if I go to rebuild this motor and it is an auto motor, is there anything else that I should be worried about? Corrosion resistant valve guides? anything else to check for to see if it is a auto or marine motor?

Block casting number is 10243880

Pic for reference

[Nautiquehunter]

600 hours is very low for a rebuild. I talked to PCM years ago they said the only difference between the automotive and marine engines are the bolt on accessorizes. Freeze plugs , exhaust manifolds ect.

[bturner]

I've heard the same as above countless times over the years. One place that I've used over the years over and over again that really knows their stuff is Discount Inboard Marine.

https://www.skidim.com/

These guys carry every PCM engine rebuild part you'll need and have people there that actually know what they're talking about. They can provide a one stop shop for all the gasket kits that you'll need to do the job right. Give them a call, I'm sure they'll be able to answer most if not all your questions.

Please keep us up to date on your rebuild as many of us love to see or would love to do this stuff but just don't have the time or in my case the facility to do it in. Would love to know what all you plan to do to prep the block. Would seem like a great opportunity to "square it out". The last engine I was involved with (years ago) we were lucky enough to have a great machine shop that we basically dropped the block off and picked it up with the rotating assembly completed. They tore it down for us then cleaned, surfaced and aligned bored the block then balanced the rotating assembly. It wasn't cheap but what a great running engine it was.

[T_Bone17]

I've been looking around for parts, I havent tried skidim yet, I will see what they can do.

600 hours is pretty low for a rebuild. It was mostly the oil leak, which was primarily coming from the timing chain cover and getting the timing chain cover off, required pulling the oil pan and that wasnt possible in the boat, so I pulled it. And now that it's out I'm thinking might as well give it a refresh at least.

The hours had me suspicious that someone swapped it, or did a half *** rebuild job.

The steel freeze plugs seem to be a consistent item that points to it not being an original marine motor.

I'm looking into local machine shops. I will probably have them hot tank the heads and block, deck the heads, I will probably do the rest. Debating them regrinding the valve and valve seats, and replacing the guides if necessary. Trying to keep this a pretty budget refresh though.

[obd666]

If I recall correctly, the 2000 models didn’t come with the 5.7 gm block. So if that’s what it has, its prolly a secondhand or remanufactured someone crammed in there. Good luck with rebuild


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[T_Bone17]

If I recall correctly, the 2000 models didn’t come with the 5.7 gm block. So if that’s what it has, its prolly a secondhand or remanufactured someone crammed in there. Good luck with rebuild


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I confirmed that they did make the PCM 350 for the 2000 model year, it was just a rare option, most came with the 351.

[Nautiquehunter]

PCM offered a GM 350 in 1989 I went with the 351 Ford because I didn't want the odd ball in a 351 world.

[shag]

600 hours is very low...