Motor options

[Shadow91]

Okay, so im trying to decide on what to do with my current boat. Found out last night I had a nice crack in my block and water in my oil. Also found out that there is water getting into the manifold internally. While the crack in block could probably be patched or band aided Im worried more about the water in the oil.

Co worker is trying to tell me the water that is leaking into the manifold could be my reason for water in my oil. That true? Cant see how, but figured id ask.

Ive read that I need to stay with a 4 cylinder, either another 2.5 or 3.0 mercruiser engine. Any other options or is that it? The v6 motors the gearing is incorrect and wouldnt work right?

I did find a 2.5 OMC out of a 1972 reinell boat that the guy only wants $100 for. Would it work? I assume id need to change the manifold, thermostat housing and electrical system, but the block and head should be the same, right?

this is the engine. going to look at it tonight, complete with the drive. Looks rusty but the owner swears its all there and in good shape. Might be worth the $100 gamble if its compatible with my boat.

Would need to replace my 252ftrctr and mount to a 400 stinger stern drive


Thanks a bunch, and hopefully i can get this boat on the water once again.

 

[Scott Danforth]

what motor/drive do you have now. including the year?

 

[Shadow91]

Model # 252FTHRCTR Serial # J761532

Drive Model # 982740

Believe its a 1983 2.5 OMC from the engine you have provided me in other posts attached to a 400 series stinger sterndrive

Its in a 1986 Seaswirl Spirit

 

[Scott Danforth]

I answer about 2 dozen issues per day. sorry I dont remember what you have

I would look for a 1980-1990 3.0 liter (OMC, Mercruiser, Volvo Penta, fork truck, generator, etc.). it will bolt in place of your existing motor. I would not look at a 45 year old rusted motor. if you find a 1981-1985 OMC you can use the whole motor, intake, exhaust, etc. if you get a Mercruiser or Volvo, you will need to transfer the OMC stuff onto it.

in 1991 they went to a 1-piece rear seal and the flywheel bolt pattern changed so your current coupler wouldnt work and there is no OMC coupler for the 1-piece RMS cranks unless you take the ford coupler and have it custom machined.

you will need a new exhaust manifold because yours is most likely busted like your block.

 

[Shadow91]

Sorry if i came off rude, wasnt my intention. Was just stating that thats the information I have on the motor from what you have provided me.

So basically I HAVE to find a 80-90 2.5 or 3.0 engine.

You mention a fork truck or generator? Any specifics to try and search for those? Maybe i can find one used and hopefully not being marine, cheaper.

Looks like a new manifold is about $350 for a brand new one, so I just need to find a block and head assembly and go from there.
Thanks a ton Scott.

 

[Scott Danforth]

they are the same motor, comes out of the industrial motor division of GM. they wont be any cheaper.

if you look around, plenty of free rotten boats that run ok on CL. the 3.0 is one of the most prolific motors out there as it is the entry level boat. look for a late 80's bayliner. the boat rotted from around the motor.

 

[Shadow91]

I have seen a few boats that people are giving away for free for whatever various reasons. What do you do with the hull/trailer after?

 

[Scott Danforth]

you part out what you can from the hull. you then haul the hull to the dump and pay for disposing of the hull. then you sell the trailer. in most cases, a bit of time and work and your motor could be free.

 

[Aussieguy55]

if the donor boat was run in salt water without Fresh water cooling, it may be ready for the scrapyard as well as your old one

 

[Shadow91]

Hey Scott, browsing offerup and my local craigslist i have found a few more options. Both these engines the owners do not know the year of the engine but I got whatever details i could.

First one is a full boat/drive/trailer. The boat is hammered, interior gutted, but trailer is nice and engine is questionable. Owner doesnt know the year of the boat or engine, said he can look up the title and find the year if im interested in it. Boat hasnt been registered since 1994.

Engine looks correct for the most part. Biggest concern I have is the #1 cylinder had resting water in it. I checked every last inch for cracks and couldnt find any. This engine looks like a possible good core for a rebuild if possible, and I assume i would need to change the thermostat housing and intake manifold. But again, not sure.

Numbers on side of engine are 3937746 D169

Second option is just the engine and 400 omc stern drive. Guy has the engine on a stand and can varify it runs and has no issues. Said the drive needs new shift cables but everything else works. Reguardless i dont really care about the drive, however im not sure on the motor again. Looks like it was a enclosed cooling system, so i would have to figure out what i would need to change over.

Numbers on the side of the engine are 2770087 53 89
picture of engine before it was removed.

Both options are $300.

 

[kenny nunez]

Since the OMC pictured is fresh water cooled that may be the best so far. Leave the fresh water system in place and just connect your water supply hose to it.
Replacing the shift cable on a 400-800 takes some special tools.

 

[Scott Danforth]

Get the OMC with the drive. Your going to need spare parts

Skip the motor with water in the cylinder

 

[Shadow91]

Okay, will the OMC, he told me it's out of a 1980 trophy. Which would probably put the engine as a 79 or so.. would just the thermostat housing and manifold have to be changed over?

 

[Scott Danforth]

79 or 80 would ve hydro-mechanical shift drive

 

[Shadow91]

Yeah and I have a full mechanical drive right?

And what all do I have to do the swap blocks to make it fit in mine? Just thermostat housing and manifold? I assume the head/block are all the same?

 

[Scott Danforth]

The block and heads are same up to 1990. In 1991, the block changed for a 1-piece RMS

 

[Shadow91]

Okay awesome. That's what I needed to confirm.

 

[Shadow91]

So if I take the entire enclosed cooling system, would it all easily mount to my boat? And what are the advantages/disadvantages of enclosed vs raw water cooling?

 

[Shadow91]

Got the engine today. Gonna hopefully have this in the boat tomorrow and running by end of day. Thanks guys!

Think I'm just gonna change my thermostat housing and use the existing manifold and keep it the raw water cooling. Anything else anyone suggest?