Cummins 903 / Detroit 8v53N

[LENZ]

1977 Cummins 903 and 1972 Detroit 8v53N Diesels (1500 hrs on both), Which is the better of the two? or are they about the same when it comes to quality and performance? Parts availability? Which would last longer? (weekend cruising 8-10 knots) I had a gentlemen looking at my boat the other day and ask me that question, I said "not sure?" but I told I might be able to find out on the Hatteras Forum. Looking for pros and cons..

Thanks
LENZ

 

[Boatsb]

That's like asking which car is better a 1969 camaro or a 1964 mustang. Both may be in great shape but the unknown is the issue.

Either engine may give him years of trouble free use or break tomorrow. Both have most parts available but prices vary.

 

[REBrueckner]

My own view is that which engine may have originally been superior 30 years ago is not so relevant now, if at all. What really matters is the care and use an engine has had. At 1500 hours those engines likely have not been used enough. If either has been dormant for the last few years I'd avoid that engine. Much better if an engine has been used regularly.

I'm pretty sure 8V53 parts are more generally available because that engine was likely produced in greater numbers. Seems like more Hatts had the 8V53's than Cummins, but I not positive about that, nor exactly why that might have been.

Try a search on EBAY for each engine type over a period of time and see what engines and parts appears. Also try BOATS AND HARBORS listings...two sources for anecedotal evidence. I personally decided NOT to view a boat which I would have liked some years ago because of limited Cummins parts availability.

 

[LENZ]

My own view is that which engine may have originally been superior 30 years ago is not so relevant now, if at all. What really matters is the care and use an engine has had. At 1500 hours those engines likely have not been used enough. If either has been dormant for the last few years I'd avoid that engine. Much better if an engine has been used regularly.

I'm pretty sure 8V53 parts are more generally available because that engine was likely produced in greater numbers. Seems like more Hatts had the 8V53's than Cummins, but I not positive about that, nor exactly why that might have been.

Try a search on EBAY for each engine type over a period of time and see what engines and parts appears. Also try BOATS AND HARBORS listings...two sources for anecedotal evidence. I personally decided NOT to view a boat which I would have liked some years ago because of limited Cummins parts availability.

Thanks Rob that's all I needed to know.

Thanks again!
LENZ

 

[fissioneng]

I personally decided NOT to view a boat which I would have liked some years ago because of limited Cummins parts availability.

I did the same on a 43DC. Well kept engines, but the owner had a heck of a time getting parts at reasonable prices. That was 2.5 years ago. The boat looks like it just went under contract.

 

[DLCameron2]

Hi Dave:

My 1977 43DC had VT 903 M1's these were 325HP driving continental gears. The boat cruised effortlessly at 17.5knots, these engines were built in an era where major overhauls were not expected until well after 5000hrs. I had a problem with one raw water pump, had it rebuilt by Jabsco and problem went away. I ran them for 8 seasons with only 2 problems the raw water pump and a broken fuel pump shaft. These engines have the "CUMMINS Pressure Timed injection, which is a mechanical early version of a type of "Common Rail" system. They are built to be bullet proof. Much quieter than 8V-53's and the boat is much faster (the M rating was 425HP if someone can find a 43 with that).

CUMMINS is a major customer of mine in my work, the 903 is used to power the Bradley Fighting vehicle. I cannot say much but suffice it to say it is still in low volume production in Columbus, IN and still being developed for more power. The electronic fueled version would be a blast in a 43 DC although I would expect keel and chine walking LOL! Call me if you want further info.

DC

 

[REBrueckner]

DC brings up a good point about the noise of DD. [So for "girly men" that could be a consideration. More importantly, the "admiral" might have a preference.] It's not that Cummins are especially quiet; almost any diesel of that era woud be quieter than a Detroit..that's one reason why so many love them so much!

It might also be the Cummins are more fuel efficient, being four cycle...but whether that is true and to what extent I have no direct knowledge.

 

[stormchaser]

Interesting...both my wife and I LOVE the sound of a screaming Jimmy,

 

[Brian Degulis]

DDs are louder than 4 stroke engines of the same era from a decibal standpoint. In other words if your standing next to the engine the DD is louder. On the boat itself a DD is probably quieter. DDs produce higher frequency noise than a 4 stroke. Higher frequency nosie does not transmit thru the structure of a boat as much as low frequency noise. Most of the noise in our boats is structure born. So unless the engines are on very soft mounts most boats with DDs will be quieter throughout the boat even though the engine itself is louder. The diffrence is more noticable in the lower RPM ranges but probably still better all the way to WOT. This only aplies to engines of the same era. Today's 4 stroke engines are quieter and smoother than anything produced 25 years ago.


Brian