Old School Engine Discussion - Small Cam Cummins Driveability

The K100, yes that is the truck that has the 855 in it.

 

You said it before I could. Enjoy it a 40 year old small cam don't run like 600hp ISX. You will waste a lot of money trying to squeeze out the hp and in the end either still be disappointed or ruin the motor. If you can't live with it spend your money on a newer high hp engine and replace it.

 

Nice ride. Are you workin it or is it a toy.

 

All my trucks are technically toys, I dont drive for a living. The injectors in it flow over 3 times the amount of a stock 400 injector, it is quite beyond what would be usable on the street as a working truck.

 

Perhaps sled pull's ?

 

Yeah, it seemed to work well for the single pull I was able to attend before the season was up after getting it rebuilt, so much so that I have to rethink my gearing to take advantage of the power.

 

You have a classic truck. Run it as such. Those are fast disappearing I say.

 

To be clear, I never said a 3406 Cat was more dependable than a Cummins. Of my 35 years in a truck, I'd say a good 90% of the trucks I drove ( lost count) including my own, were Cummins motors. I got a lot of miles out of them because I babied them. I had friends, who would pull away from me going down the road with their Cats, but paid the price for that, and some were on their 3rd repair, while my Cummins chugged along. But those were different times. We've become accustomed instant gratification ( got to happen now) and an old Cummins, is just that. I drove a Freightliner with a 500 Detroit, and that had some power ( and was a million mile motor, to boot). That's what I'd put in that ol' gal.

 

Ok, just to bring what the OP originally stated so we can keep an eye on the referred to issue.
70 mph with 78k load is doing quite well with a 290 IMO. But does anyone have information on the governor working on this vintage of cummins? If I recall correctly, there is a spring on the throttle lever at the pump.? Is this correct? If that spring gets weak or is in the wrong position, the old mechanical pump can push back on the throttle when a load is sensed, and that spring needs to be able to counter that force. ? I could be very wrong however.
Typically, if a load is sensed, and more fuel can be sent, the turbo should spool up at least some. But the manifold pressure gauge should rise along with it. I just dont remember what proper psi was for that engine. 22 is low for today's tech, but might not be all too far off for the 70s. If you can find the pressure spec from a cummins expert, and it should be higher, then my money is on a governor setting being off.

 

Not around here, we have 3 K100s and a W900A, old iron never dies.