3.0L Mercruiser - Bores too bad?

[Poorboy Pontoon]

I'm trying to put this engine back on the water as cheap as possible (of course). The whole boat is not worth that much. This engine has been sitting for about a year. I got it and the whole outdrive for $150. So, good deal until I remove the manifold and find a crank in the outside water jacket, which I "repaired" with JB weld.

So, needless to say, do you guys think these bores are too bad to run in an old boat? I can catch my finger nail on some of them? Or should I tear the short block apart and sink more money into it?

Thanks & I know the pics are not the greatest.

 

[Don S]

Re: 3.0L Mercruiser - Bores too bad?

Put it together, start it up and run it and see how it does. If you have a crack in the manifold, you very well may have a crack in the block.
Looks to me like there has been water in the cylinders before and rust on the rings may be what caused the scratches.
Doesn't sound like anything else on the boat is worth sticking money in the engine.

 

[Fishermark]

Re: 3.0L Mercruiser - Bores too bad?

I would agree with Don. IF you have pictured the worst of your cylinders, then I think you will find you will not have any problems.

 

[Poorboy Pontoon]

Re: 3.0L Mercruiser - Bores too bad?

Yes, those are the worst. Compression is right around 90-100 psi for all the cylinders cold. The block did have a crack in the water jacket. I really have two engiens that I am trying to make one decent one out of that will last a couple more seasons. I work at Roush and all the guys in the shop think that I should not have JB welded the block and that I need to deck and hone the block. Deck surface is out maybe......003"-.004" across 12". I know the bores are not pretty, but with some good oil, I think it would still function decent. It was a running engine that was weeping a little water out of the jacket.

I also had the head(s) checked and I am using the best one. it was decked and the seats/valves trued up. They did find a previous weld job between #2 & #3 cylinders, but it looks good and stable. .007" to make the head flat.

I just hate to throw another $500-$700 at it to make it function decent. The whole boat is not worth $3k. But it is cool to have the I/O on a pontoon boat. Its great for the kids and I don't have to worry about scratching it up........

Thanks for the feedback. Does my approach sound reasonable?

 

[Fishermark]

Re: 3.0L Mercruiser - Bores too bad?

I don't have any experience with cracked blocks, etc, but I have read on various posts here that some have had good luck with fixing an external crack - yes, even with JB Weld. On a pontoon boat you're never too far from help I assume? (Maybe a dangerous assumption). If it were me, I wouldn't do it if you ever get in situations where it would be dangerous to break down - like offshore, etc. But for tooling around a lake, etc. I would say go for it and see if it works.

 

[fat fanny]

Re: 3.0L Mercruiser - Bores too bad?

For what the motor is for and the resources your employer has. I believe I would deck the block and skin the cylinders @ any rate with what you have in it and what you could get out of it on the water or in a future sale. Never skimp if you can and is it worth to due so if you have a choice?