Cummins V8-300-M

[SeaEric]

Does anyone here have experience with the old 1970's vintage Cummins, I think the model is V8-300-M? This is a 300 HP, non turbo that I believe to be the same 785 cubic inch V-8 block as the turbo VT-370-M which is 370 HP. I realize that these are heavy, old, for the most part old technology with not much horsepower for their weight. I also understand that internal (rebuild) parts, although expensive, are still available. Some of the externals like heat exchangers are no longer available new, but some good used stock exists. What I want to know is: are there any inherant problems, known defects, scary stuff to be concerned about in owning a boat powered by these old motors? Are they any better or worse than an old pair of GM 8V53's of the same vintage? The boat in question is a 1970 model in beautiful cosmetic condition, well maintained as far as is apparent (pre survey) and the subject engines have 3200 original hours since new, never rebuilt. Any thoughts, comments, observations?

[SKYCHENEY]

I may be wrong, but I believe that the Coast Guard runs a bunch of these old Cummins still. I'm not sure which models, but it has been said that they also have many of the spare parts tied up for their own use. I believe that these are good engines because if they were not, you wouldn't see the Coasties still using them.

[Banshee36]

Would that be the famous 9 0 nothings?

[SeaEric]

I assume that you are referring to the 903, which is a 903 cubic inch engine. If I understand correctly, the 903 was introduced later, after the V8-300 and VT-370, but I may be wrong about that. Still lots of those old 903's out there crashing around the seascape, for sure.

[mstailey]

SeaEric;
Shoot DLCameron2 a message. He's a great source for Cummins.

Sky Cheney;
That would be the Cummins VT903M used in the Coast Guard 41UTB. Very much in use today. Great engines for those who know what they're talking about.

[mstailey]

You may also want to try Cummins - Bridgeway LLC.
3 Alpha Drive
Pittsburgh, Pa. 15238
(412) 820-8300

[SKYCHENEY]

There was another VT that shared many of the same parts with the 903. I just can't remember the model. If you call your local Cummins dealer, they are usually pretty good about sharing info with you, especially if you have serial numbers off the the engines

[mstailey]

Sky Cheney,
That would be the VT555M engine.

[dsharp]

Seaeric, You're right, it's is the same engine as the 370 hp but naturally aspirated; My dad repowered several boats with them years ago and they hold up fine. It's an earlier engine than the 903 series. In my opinion it's a hell of alot better engine than an 8-53. Doesn't sling oil everywhere. You can still get parts for them. Some people didn't like the capitol gears that they put behind them; they didn't shift as fast as an allison. It took them about 1-2 seconds to shift from forward to reverse. When you're about to hit the dock that seems like an eternity. He still has one in the barn that has been rebuilt with a new crank in it. Needs new heads. I didn't get them drained in time and I let it feeze and it cracked a head and the circulating pump. He's still bitching about it evertime he walks by it - it was only about 25 years ago.

[Avenger]

Would that be the famous 9 0 nothings?

That's funny, I thought that was just a local expression here on LI. Knew a guy who had one in a truck, put bearings in it every 30K miles.