Small Cam 290 injector number?

[hethead]

Like many, I'm tuning my 250 up a little. I've built lots of motors but not a large diesel before, so most of my knowledge is only from reading. I also know many active people on this forum have hands on experience with small and big cam Cummins.

All I've done so far is a straight pipe and increased my rail pressure and I'm pretty happy with the power and EG temps. I'm just shooting for a sturdy 300hp, so I'll be adding a turbo, intercooler and piston coolers to keep it hard to hurt. I've done a lot of machining and fab work so I'm pretty confident I can do the piston coolers (but that has yet to be seen!).

What I would like to do is keep the increased fuel volume but lower the rail pressure and make life easier on the cam. So I'd like to fit a set of whatever injectors came on the 290's. (bigger holes, easier to squirt fuel through, easier for the cam to squeeze).

I've looked but I can't find a part number to order any. My thinking is that a remanufactured set of those would be easier and maybe cheaper to replace on the road than a set of custom flowed ones. I'm picturing a lot of them on shelves in dusty boxes from the days when half the trucks on the road had an 855....

 

[simp5782]

Like many, I'm tuning my 250 up a little. I've built lots of motors but not a large diesel before, so most of my knowledge is only from reading. I also know many active people on this forum have hands on experience with small and big cam Cummins.

All I've done so far is a straight pipe and increased my rail pressure and I'm pretty happy with the power and EG temps. I'm just shooting for a sturdy 300hp, so I'll be adding a turbo, intercooler and piston coolers to keep it hard to hurt. I've done a lot of machining and fab work so I'm pretty confident I can do the piston coolers (but that has yet to be seen!).

What I would like to do is keep the increased fuel volume but lower the rail pressure and make life easier on the cam. So I'd like to fit a set of whatever injectors came on the 290's. (bigger holes, easier to squirt fuel through, easier for the cam to squeeze).

I've looked but I can't find a part number to order any. My thinking is that a remanufactured set of those would be easier and maybe cheaper to replace on the road than a set of custom flowed ones. I'm picturing a lot of them on shelves in dusty boxes from the days when half the trucks on the road had an 855....

are they top stops or non top stops?

 

[hethead]

are they top stops or non top stops?

I don't know. I assumed the NHC250's came with non top stops, but your question makes me think I was wrong to assume that. I believe it's original with 30,000 miles on it (and 1,000 hours) but I haven't had them out yet. I'll be pulling a 30k trailer for personal use, so not working too hard but also not just a parade toy either.

Truck is a '71 M820. If the 250's in them came with both top stop and non top step, I guess I'd need to start there...

 

[simp5782]

I don't know. I assumed the NHC250's came with non top stops, but your question makes me think I was wrong to assume that. I believe it's original with 30,000 miles on it (and 1,000 hours) but I haven't had them out yet. I'll be pulling a 30k trailer for personal use, so not working too hard but also not just a parade toy either.

Truck is a '71 M820. If the 250's in them came with both top stop and non top step, I guess I'd need to start there...

The small cams can come with either.

What is the ESN or CPL?

 

[hethead]

I have the truck parked up North, so I can't take a look. If I win the auction for a log trailer this Thursday, I'll be up there next week, using it to tow it home. I'll get the CPL then. I probably should have written it down by now. I appreciate your help. All I know about it is it had a #45 button in it. Not too much to go on!

 

[WillWagner]

How are you gonna add piston cooling nozzles....asking for a friend

 

[hethead]

How are you gonna add piston cooling nozzles....asking for a friend

Pressure lines would be external. I'd drop the pan and drill the holes into the block from the outside. I'd have a plastic vacuum nozzle cut at a 45 with a hole in it that the bit goes through., up against the block. So I'm drilling in a vacuum. When the bit breaks through, the majority of the metal is sucked out. Then thread it, etc. That's the plan anyway... If I don't feel confident, I'll just not do it. But I'd like to have them if I can.