[AT] Detroit Diesel was gas versus diesel trucks

toma at risingnet.net toma at risingnet.net
Tue Nov 22 10:15:39 PST 2016



On Tue, 22 Nov 2016, charlie hill wrote:

> you are mad at them but really you aren't.  The power band is very narrow,
> typically between 2100 and 2650 rpm and 2650 is stretching the top end.
>
> In truth they are probably better suited for running power units
> (generators, etc) where they sit and

To bring this into an antique tractor frame, One of my first jobs back in 
the '60's was driving an HD 5 AC tractor. The farmer I worked for had 3 of 
them. They were equiped with 2 71 Detroit diesels. Two were used for 
tillage only and had BG boxes for hydraulics. One was equiped with a 
Gar-Wood dozer and brush rake for clearing brush.

Some of the older guys complained that they were underpowered. Said they 
didn't match up to the M, I could never understand that because the M was 
a smaller tractor. Maybe in the same field they would not keep up with 
properly sized implements. The AC M was a hotrod. The HD 5 had a 
transmission kind of like a truck. I got so I could shift it on the fly. 
You did have to shift down into 2nd when turning uphill sometimes.

This guy farmed 1000 acres at times, back then flax was king and oats, 
oat/vetch and barley. Another farmer who farmed 1000 acres had 2 HD5's 
with HD 7 motors, 3 71 Detroits, he said they were just right. They would 
work in 4 th gear all day long, up hill and down.

I liked them just fine, I was used to an old Cletrac and a worn out Cat 
20. I thought they had lots of power. I had not run a D 4 or TD 9 at that 
time. I still remember how they smelled when you started them up on a cold 
morning. Back then starting fluid did not come in a spray can, it was a 
liquid. We would take the top off the precleaner and drop a capfull in the 
air cleaner, they would fire right up.

When AC went to diesel in the late '30's they used detroits in all their 
crawlers. HD 5 2 71, HD 7 3 71, HD 9 4 71, 6 71 and 6 110 were used in the 
bigger tractors, I am not sure of the model numbers. In 1956 AC bought the 
Budha engine company and started putting 4 cycle diesel in their tractors



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