GM diesel

Sat Jul 20, 2013 7:05 pm

Does anyone know what the numbers meant (if anything) on the old GM Detroit diesels? Such as; 4-71. I was thinking maybe the number of cylinders and the cubic inches for each cylinder.

Re: GM diesel

Sat Jul 20, 2013 7:22 pm

The 71 indicated the engine series and the first number was the number of cylinders. I used to run a Euclid 82-30 dozer that was a 6-71. It was a six cylinder. Not sure how you calculated the cubic inches.

Re: GM diesel

Sat Jul 20, 2013 8:40 pm

Barnyard wrote:The 71 indicated the engine series and the first number was the number of cylinders. I used to run a Euclid 82-30 dozer that was a 6-71. It was a six cylinder. Not sure how you calculated the cubic inches.


Per Wikepedia:

The 71 in the model series designation refers to the displacement per cylinder in cubic inches (actually 70.93 cu in / 1,162.4 cc). Bore and stroke is the same to all units, at 4.25 x 5.0 inches (107.95 x 127 mm).

Re: GM diesel

Mon Jul 22, 2013 12:38 pm

Birddog, you and they are right. It is number of cylinders and cubic inches per cyl. 4-53 is 212 cubic inches, 6-53-- 318ci, 6-71--426ci, 6-92--552ci etc. Biggest I've seen is 16V-110--1760 ci in a whole tree chipper. I think Detroit made some locomotive and tug motors that were even bigger.

Re: GM diesel

Mon Jul 22, 2013 6:18 pm

Thanks all.

Re: GM diesel

Tue Jul 23, 2013 6:28 am

The rarest tractor I ever had was a 1959 JD 435D with a 2 Cyl. GM diesel in it.
I think it was a 271 engine.
We used it on the farm and traded it on another tractor, before antique tractors became popular.

Re: GM diesel

Tue Jul 23, 2013 6:28 am

The rarest tractor I ever had was a 1959 JD 435D with a 2 Cyl. GM diesel in it.
I think it was a 271 engine.
We used it on the farm and traded it on another tractor, before antique tractors became popular.

Re: GM diesel

Tue Jul 23, 2013 9:27 pm

71 & 53 series were two stroke. No fun to be around much less work on. A lot of noise for the HP they made... IMHO
The best thing about them (6-71) was the blower which are still used on dragsters. (or their clones) IMHO
Blaw-Knox pavers, Terex, and Euclid used a lot of those engines. (I've been away from construction equipment for 30 years and I believe most are gone now, or bought out)
Just my 2cents worth..