Can't post in my own topic about found a strange one

am no expert by any means but not all applications for the 671 were high horsepower or high rpm. There was a myriad of different parts internal to that engine for as many applications. I think with a two valve head and the right injectors the bottom end of the 671 horsepower was around 80 horsepower at 1400 rpm. I don't know what the torque curve would look like either. I might be able to shed some light on this later i hope.

Trying to reply

I think that I finally might have figured out how to reply on the new system. I have two D6 4R tractors that were repowered with 6-71 Detroit engines. Surprised to hear that the TD 18 was possibly not up to the extra power as these tractors never seemed to have any issues. I have used them a little since I have had them and while I think they act like they may have more power than turbo 9U I don’t think that they are high hp versions. Worked really well for high speed operations like cross harrowing or spraying. Was told by the one original owner the biggest down side was the tracks wore faster because they ran faster all the time using 4th gear which was about 5.5-6 mph with the fast engine rpm’s. Mike

Sorry, meant to post this in the earlier posting.

I had an idea that this transplant might have had roots in the agriculture tractors and not so much industrial side.

Using 71 series GMC on marine applications, we used rule of thumb of 30 horses per hole.