Putting a new motor in 84' Cuddy

[jfoster]

I have an 84' Celebrity Cuddy Cabin that needs a new motor. It has a GM 350 in it now. Can I replace it with any 80-85 GM 350. Like say one out of an GMC1500 that is being parted out. Are there any serious draw backs to doing this? I have found several engines that are about 10% of the price of buying a new marine motor.
Thanks for the help in advance.

 

[arks]

Re: Putting a new motor in 84' Cuddy

Are there any serious draw backs to doing this?

Um, Y E A H !
It's been discussed aud-nauseum here in other posts. An automotive engine, while internally similar, should NEVER be used in a boat because nothing about it is marine rated. Even with a working blower, gas fumes can collect in the bilge and the smallest spark- be it from the starter, alternator, coil, or distributor- will turn the boat into a bomb. This is serious business and not something to take lightly. DON"T DO IT.

I have found several engines that are about 10% of the price of buying a new marine motor.
Thanks for the help in advance.

That's because marine engines have more expensive ignition-protected components to prevent sparks, special water pumps, and brass freeze plugs (which won't rust like steel).
I'll say it again- DON'T DO IT!

I don't mean to get down on you- don't take it personally.
Oh, and WELCOME to iboats!

 

[jfoster]

Re: Putting a new motor in 84' Cuddy

Even if i just use the block?
Forgot to mention that the old motor has two cracks in the block. Some of the other accessories like starter and water pump are new and all are marine. I would plan on re-using everything but the engine block.
Thanks Again.

 

[arks]

Re: Putting a new motor in 84' Cuddy

OK, then that's a different animal.
If you change the freeze plugs and use a marine water pump, then an automotive block would work. Just be absolutely certain you don't use any parts that aren't ignition-protected. The carb needs an approved flame arrestor, too. I could go on and on about specific requirements, but hopefully the boat is already setup properly and you can switch everything from one to the other correctly.

The donor block needs to be a strong one- boat engines work a lot harder than car engines. Good luck.

 

[jfoster]

Re: Putting a new motor in 84' Cuddy

It was running last summer. One lap around the lake and blew the engine. Still runs but has cracks in the cylinder wall of #'s 8 and 1, so I wanted to replace just the block.
I'm am going to try and match up casting #'s if possible but haven't had much luck finding the exact match. Hoping to find one that is the within a few years of my model.
Thanks for the info.

 

[jfoster]

Re: Putting a new motor in 84' Cuddy

Update: I found a motor pulled from a Chevy truck on Craig's List. And it has the exact casting #'s. Going to take a look at it this weekend.
Thanks again for the help.

 

[JorgeE]

Re: Putting a new motor in 84' Cuddy

Hey J,
Take a look at a thread on this subject:

http://forums.iboats.com/showthread.php?t=289218
Title is: "difference between Auto and Marine engines"

Various posts in that thread point out the differences, and they will help you. The elctricals (alternator, starter, distributor) are CRITICAL that they always be marine to avoind a premature meeting with our maker.

Jorge

 

[jfoster]

Re: Putting a new motor in 84' Cuddy

Update with pics.
Motor looks good. Pulled the old motor and rebuilt new one and reassembled. Just waiting for the weather to break and put it back in.