Help/Advice on 1976 Mercruiser 888 problems...

Hello, I thought I would post my question here as it seems like there are a lot of knowledgeable people on here. I have both a question and a request for some advice concerning my 1976 Webbcraft. It has a Mercruiser 888, which of course is a Ford 302 2bbl, 188hp. This past weekend I decided to try and take her out to the lake for the first time in at least 4 or 5 years. The last time I attempted to put her in the water she immediately got to temp then over heated so I shut her down and got a tow back to the ramp. So getting her ready for the big weekend last week I replaced the lower unit water pump and also one of the bellows coming from the exhaust riser. I also did a fresh oil change and points replacement. Unfortunately when I got her down the ramp and into the water, to test the water pump replacement, she started right up and purred like a kitten but to my surprise she was pumping huge amounts of water out of the freeze plugs. I shut her off and pulled her back up the ramp and checked and 5 of the 6 plugs were gone. So I replaced those at the lake with the rubber expandable ones from Autozone. After getting those replaced I again pulled her back down the ramp into the water and started her up. Everything was fine no leaks purred like a kitten. While I sat there letting her idle I decided to check the oil dipstick just to be safe and damn if it was milky and 3/4 of the way up the dip stick. So I again shut her off and pulled her out and took her home.
So my question. Before I tear into the engine I wanted to get some feedback. My first thought is that the head gaskets might be blown, but since 5 of the 6 freeze plugs were gone I am afraid something far worse has happened. If anyone of you guys might have some knowledge about these engines I would be greatly appreciative of any thoughts or guidance. I am kinda at a fork in the road per say. Obviously its an old boat that needs work done other than the engine, is it worth the investment of replacing the engine along with the other repairs (upholstery) or do I call it dead and buy a newer boat. I mean I know that as soon as I tear down to the head gaskets I will know if that is the problem or not but I really dont want to waste the time if its 70% plus, likely that the block is cracked. Any thoughts? Suggestions?

Thank you
Jason

Re: Help/Advice on 1976 Mercruiser 888 problems...

Core plugs usually don't blow out because of a bad head gasket.
The engine not being winterized will.
Your problem is cracked heads or block, or both.

Re: Help/Advice on 1976 Mercruiser 888 problems...

mkast said:

Core plugs usually don't blow out because of a bad head gasket.
The engine not being winterized will.
Your problem is cracked heads or block, or both.

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Ditto! Block most like cracked across the top of two cylinders.

Your call as to whether replace it or not. 302's are good motors and in plentiful supply.

Re: Help/Advice on 1976 Mercruiser 888 problems...

You could updrage to the 351 with no problems if you wanted to.

Re: Help/Advice on 1976 Mercruiser 888 problems...

or not but I really dont want to waste the time if its 70% plus, likely that the block is cracked.

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Ayuh,... I'd say it's more like 99.9978469% likely the block is Cracked....

Re: Help/Advice on 1976 Mercruiser 888 problems...

J, your block is cracked, and most likely one or both heads are too.

I was in your exact position last October. I bought a boat, took it to the lake, and found water in the oil when I got home. Fortunately, my block and heads were okay (intake gasket, I suspect), but had spun two of the main bearings. So I was in your exact position, "do I put the money and time in it to fix it, or part it out and buy another". I decided to rebuild her bacause I like the looks and ride of the boat. It has been expensive, time-consuming, frustrating, maddening, confusing, excasperating, and did I mention it was expensive? And I'm still not in the water with summer here. Sometimes I wish I would have went the other way, but I am learing a lot and I will be very satisfied with myself if she ever runs again. You could get a hundred differing opinions on what you should do, but ultimitely, do what you can afford. I guarantee that you will spend more rebuilding your boat and making all nice again than you will buying another boat of similar age and size that is ready for the water. Don't do what I did, though. Don't buy a boat without a THOROUGH water test.

Re: Help/Advice on 1976 Mercruiser 888 problems...

I am right there with you.... I bought a 1979 19' Sea Ray with a Chevy Mercruiser 898 at what I thought was a bargain price. I did not do a water test so I got the boat home and hooked it to the hose. Idled for a few minutes then pulled the dip stick...water 3/4 up the stick PLUS I start nosing around the block a little closer and found where they tried to patch a crack in the block.

My thinking is I have a boat that was built in the 70's when they probably overbuilt boats. If you spend the money to fix it up it will last another 20-30 years...so I am spending the money to fix it up and going to run it for a LONG time.

Good luck!

Re: Help/Advice on 1976 Mercruiser 888 problems...

How do you figure? Everything would bolt up to a 351 just like it does a 302. The exhaust manifolds are the same, so is the intake and all linkages. The motor mounts are the same, etc.

Re: Help/Advice on 1976 Mercruiser 888 problems...

haulnazz15 said:

How do you figure? Everything would bolt up to a 351 just like it does a 302. The exhaust manifolds are the same, so is the intake and all linkages. The motor mounts are the same, etc.

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The 351W is 2" wider, 2" taller and about 70 lbs heavier. As is the case in my boat, it literally would not fit unless I rearrainged the whole back end, including the doghouse. Even then the extra weight would not be good in my boat. In some larger, deeper draft boats, that may not be an issue.


Additionally, the intake mani IS NOT the same, neither is the distributor nor the oilpan. You would also have to replace the Y pipe to hook up to the now wider exit pattern of the exhaust exit boots.