Piston installation with offset bowls??

[No Sparkplugs]

I'm helping a friend with his 4BT GMC. He's started to re-assemble the 4BT and noticed that the bowls are not centered in the piston. Piston aren't very well marked as to "FRONT" or anything, and I can't seem to find anything helpful in the Cummins manual. Which way should they be installed?

Any tips for a performance build? It's going to see a set of compounds and ~40psi so if we need to set the ring gap looser than spec or etc, tips like that would be much appreciated.

Thanks

 

[jakerc69]

pistons offset bowls

The offset goes to the.... injector side of the block, opposite the pump, exhaust side etc...

 

[CorneliusRox]

If it is a ve or ppump, they face the injectors. I think VE was the first centered style.

 

[Scooter's Roofing]

If it is a ve or ppump, they face the injectors. I think VE was the first centered style.

VP was the first centered... VE and P7100 the injector location is the same in the cylinder head... therefore same piston bowl location

 

[CorneliusRox]

I meant VP. I must have mistyped and wrote VE. Sorry about that.

 

[No Sparkplugs]

FWIW it is/was a P-pump engine...guess I left that out

 

[CorneliusRox]

FWIW it is/was a P-pump engine...guess I left that out

It really just comes down to the head. You can run a Ppump on a 24V head with VP injectors set to pop at the correct pressure.