Turning up power on PT pump on 855

We have an 835 Versatile tractor with a 855 cummins in it. Its a 1982 model rated at 230hp and 800 lb ft of torque. I would like to know how to get up to 250hp and 850 lb ft torque out of it. I think all one has to do is remove a plate from somewhere on the injection pump and drill a larger hole in it but I'm not sure of where to do this at.



I hope someone can help



CR Toney

 

Diesel Injection of Pittsburg has been tweaking the 855's for years. Go here for lots of info:

http://www.dieselinjection.net/frames.html



Click on "Bruce's Horspower and Torque Articles".

 

If it is turbocharged and has the aneroid head on the back of the PT pump, all you have to do is put a bigger button and spring in the pump from a 250, 290, 335, 350, 400 etc. However, there are better and safer ways of turning the PT up ,however, it takes some calibration from the stand. A good tech on a calibration stand can make a PT pump engine really run awesome and still stay within the factory tolerances. The spring and button is a cheap easy way but can get a little toasty if you dont watch your foot.

 

Get a pyrometer, whatever you do. Don't get any bogger implements, just pull it faster. Clutch may not be happy about it.



Don't recommend it, but you could just put a pair of Vice-Grips on the return fuel line. lol It will increase the fuel pressure. The PT stands for pressure/time. More pressure means more fuel and thus more power. Get a fuel pressure gauge.

 

Make sure it has a turbo. In the automotive market, most 250 hp and less 855's were N/A. Not sure about tractors





"NICK"

 

230hp 855

The engine is rated at 230hp at 2100rpm and 800ft lbs at 1400 rpm the other models are 250/850 280/950 the only difference I could find was rad size on the 280 hp and one extra fan blade on the 250 hp. The injector cups had a different part # for higher flow. I thought if I could do a slight adjustment I could up the power at a slightly lower rpm. We have an C series in a tractor that is rated the same but mated to a powershift doesn't pull near as well 2mph slower with same load.



CR Toney