Marine Engines Any Good?

About a week ago I was on a property that is being cleaned up, lots of junk around. I bought a BMW R60 and two Honda trail 70's and left in the early evening. Returned in the morning to load them and the Hondas had already been stolen so the owners offered me "store" credit. There are two GM marine engines, a four cylinder Chevy and a V-6, it looks just like a Buick but I did not check the bellhousing pattern. Are they any good for a Jeep application or is there some difference that makes them useless? They look real clean and have been stored properly. Did I mention that thieves suck???

 

One thing, you need to know which direction they rotate. (The engines, not the thieves.)

The pair of GMs may be opposite rotations.

 

Is there actually anything different other than the cam and distributor drive gear? Different oil pump?

 

One is a four cylinder, the other a V6. these were not mounted as a pair in the same boat.

I do not think the GM "Mercruiser" 4 cylinder was ever used as a pair with opposed rotation. I don't know much about what the marine V6 would be, but I doubt it is Buick.

My first wife's uncle was given a pair of 327 Chevy engines taken out of a twin screw boat that had crashed. He gave one to his buddy and installed the other in his pickup truck. He got it running right away, and then found out he had the reverse rotation engine out of the boat. In case anyone is wondering in a twin screw set up in a boat the engines rotate opposite to each other to balance out the prop wash and keep the boat from going sideways.

There have been a lot of the GM made Mercruiser 4 Cylinder engines converted to be used in Jeeps. Good engines..

 

Ayuh,...... The Mercruiser is either a 153cid, 2.5L,(just a pulley on the crank) 120hp, or a 181cid, 3.0l, (harmonic balancer, 'n pulley)140hp motor,.....
Mercruiser doesn't, 'n has never done reverse rotation motors,..... There are reverse rotation drives though,......

If the V6 has blue or grey paint on it, it could be an ole Buick, as OMC used 'em back in the '60s,....
It's not a reverse rotation,.....
Otherwise, Chevy 4.3ls are pretty common boat motors,....

Only reverse rotation motors that were used in boats, were inboards with direct drive transmissions,....

 

the boys jeep is running a marine odd fire

 

maybe it's an old wives tail, but I've heard it said marine engines are usually better than car engines. (built to handle sustained higher RPMS)

 

I have a 350 Mercruiser Chevy that was originally a reverse-rotation engine. It was one of a pair (cw/ccw pair) that had Alpha outdrives, so Mercruiser did build reverse-rotation engines. I built it back as a normal-rotation. The difference is the camshaft, and the reverse-rotation cam gears. The reverse-rotation engine uses direct-drive gears (like a L/F134 Willys) instead of a chain-driven cam.
There were many Buick 225 V6’s built as marine engines, but I have never come across a reverse-rotation version. Except for the marine wet exhaust manifolds and auxiliary water pumps and/or heat exchangers, there is very little difference with the automotive version. Some of the marine engines got “better” cam profiles, very similar to the “RV/towing” cams on the aftermarket. The biggest issue with a marine engine is to know if it was raw-water cooled. If it was, was it exclusively fresh water? I have thrown away several very desirable (casting number-wise) Big Block Chevy blocks and heads because they were salt-water cooled and were literally rotted through.
Your “credit” V6 is very likely a Buick 225 that will easily adapt to Jeep use. Mercruiser also marinized the Chevy 4.3 V6. There were several Chevy 4 cyl Mercruiser marine engines, and even a 3.7L alloy block/iron Ford 460 head 4 cyl. of their own design.

What year is your “new” R60? I still have a ‘57 R69 I bought back in the early ‘80s. Too bad about the CT70’s. They have gotten fairly valuable.
-Donny

 

I stumbled upon a 225 odd fire marine engine years ago that was used in a small run about boat out here in San Diego. Gave the seller a hundred bucks for it figuring there might be some salvageable parts internally. I was right, however the block was complete rusted garbage. No matter how much I tried to flush the water jackets out, chunks and chunks of rust just continued to flow out. Moral of the story, stay away from salt water marine engines.

 

Marine 4.3's got three main oil galleys where as an auto only got two oil galleys with the driver side being larger to feed the mains. The two oil galley system does not flow oil well beyond 5500rpm.
So you can cam the snot out of a marine 4.3 but a standard automotive block is only practical with a max of...

 

No salt water in Nebraska. One of our bigger lakes is just down the road, several dead boats on this place. The V-6 is about Buick blue and the valve covers seemed to sit kinda' upright like a Buick. Will probably drag them home. The R60/5 is a 1973, has been inside a house but not ridden since '93, orange original paint, 70K miles and it's really pretty clean.

 

Similar to this?
This guy has a couple.
https://tucson.craigslist.org/pts/d/tucson-buick-v6-225-oddfire/7618118624.html

 

Similar to that one, yes.

 

Ayuh,...... Merc didn't send it out the door that way,......
The only right handed motors that Merc has built, since 1974 anyways, has been for Inboard boats,.....
None were ever put in front of outdrives, especially the standard Alpha 1s,.....

The Alpha 1s would self-destruct if spun backwards, in very short order, which is why Merc built reverse rotation only Alphas,.....
Mercruiser GM Engine Code Identification,....

 

the boys was a different timing cover the boat one was cast iron and wouldnt work . intake and exhaust manifolds were different.

 

Read this post with more than passing interest.I had a 1964 28' Chris Craft Cavalier with twin 283 Chevy engines. Left and right rotation. Research I did then RUMORED, that marine engines had thicker castings, I could never verify that from any reliable source. About two weeks ago i was given a 225 from a boat, I haven't picked it up yet. I'll keep you posted.

 

In case it's helpful, here's a link to the original parts book for the 225 marine engine:

https://drive.google.com/file/d/1Q7UklCs_pgJGSDltgzuCiFy2yt04b5ze/view