Cummins 855ci pistons?

[290smallcam]

Was looking at 14:1 comp. ratio pistons and they were the "newer" Tri Tech pistons for a Big Cam. Looking at my manuals for the NHC 250 and B.C.400, they have the same measurements. Can they be used in any motor? Can a B.C. piston be used in a small cam, and vise versa?

 

[simp5782]

Was looking at 14:1 comp. ratio pistons and they were the "newer" Tri Tech pistons for a Big Cam. Looking at my manuals for the NHC 250 and B.C.400, they have the same measurements. Can they be used in any motor? Can a B.C. piston be used in a small cam, and vise versa?

NHC-250 Rods, Liners and Pistons

Will all these parts interchange between engines? I picked up some piston and liners from a newer model, and there is some slight differences to them, as in the rings have a different spacing, the rods have bolts instead of nuts, and the liners have a longer shoulder at the bottom. Before I get...

www.steelsoldiers.com

 

[WillWagner]

Size of the piton is the same, 5 1/2 inch bore, it is the bowl design that makes a difference on the pistons. TriTech changed bowl design to accommodate the ring pack repositioning on the piston. 14:1 comp pistons along with the base timing...IIRC, .065, .067 or maybe .072....might make a mosquito repelling machine that won't clear up and black smoke when running down the road and maybe before the latter have reared their head, a no or hard start issue.

Take a look at videos that show cold starts on diesels. Those show what happens when the combustion temps are not up enough to lite it. They eventually clear up. Imagine that but in a climate that would normally support good combustion, but it won't clear up.

 

[290smallcam]

I know they made 400HP smallcams. Would anyone know what the timing was on those? If it's up in the 60-70's wouldn't the cam fit the NHC 250? If so installing the tri tech 14.1 or 14.5 piston would work???? Of course one would send the Pistons out to EMBEE coatings, to thermally coat the tops since there is no oil piston jets on NHC..

 

[290smallcam]

EMBEE.

 

[290smallcam]

Called and told them the size of the Pistons and they said size isn't a problem. $50 per piston.

 

[Mullaney]

Called and told them the size of the Pistons and they said size isn't a problem. $50 per piston.

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$50 seems really reasonable and would put a lot of life into those piston tops!

 

[simp5782]

I know they made 400HP smallcams. Would anyone know what the timing was on those? If it's up in the 60-70's wouldn't the cam fit the NHC 250? If so installing the tri tech 14.1 or 14.5 piston would work???? Of course one would send the Pistons out to EMBEE coatings, to thermally coat the tops since there is no oil piston jets on NHC..

CPL 695 is the 400 magnum small cam motor. Cam code E. It used 14.0 Pistons that are used in cpl 531

 

[WillWagner]

Again, it is not size, it is the bowl design. Yes, there was a 400 magnum, it was a small cam but it liked to eat camshafts. There was also a 440 magnum .It was step time controlled and ate cams faster than the 400. Keep in mind, what I had first hand knowledge on were used on OTR application, actually working the truck daily. What and how these are being used for, not the same, well except for Simp. High HP small cam wouldn't work reliably for what he is doing with his stuff

 

[simp5782]

Again, it is not size, it is the bowl design. Yes, there was a 400 magnum, it was a small cam but it liked to eat camshafts. There was also a 440 magnum .It was step time controlled and ate cams faster than the 400. Keep in mind, what I had first hand knowledge on were used on OTR application, actually working the truck daily. What and how these are being used for, not the same, well except for Simp. High HP small cam wouldn't work reliably for what he is doing with his stuff

Why I acquired a truck with a KTA, the next saga begins

 

[WillWagner]

Way cool! 450 or 600.......there was a 750 too. the saying goes, got a "K", gotta pay! Pics or it ain't real!

 

[silverstate55]

Way cool! 450 or 600.......there was a 750 too. the saying goes, got a "K", gotta pay! Pics or it ain't real!

You mean there’s an engine that has more expensive parts than a Caterpillar?!?

 

[290smallcam]

Don't hate on the Kitty's!!

 

[WillWagner]

IIRC, about 350 a hole to fix. A cam was around 4k. The cam is a giant heavy chunk of sharp metal.