big cam 400 cummins tricks

My dad had an 88 or 89 cpl 838 315 formula. They prob put lower compression pistons in it if they rebuilt it to 400 specs. I think the 315 had 17:1 from the factory. Thats the weak link if your gonna throw fuel to the lower hp big cams.

 

Thanks for the info.
What would baba trick way to figure out compression? A compression gauge on the injector hole? Or, fill cylinder with liquid and siphon back out and measure? Lol.
There has to be an easy way.....

 

STOP telling him to change parts when you don’t have a clue what he is starting with, just because it is a 315 doesn’t mean jack.

Everyone that is scared of the 838/840 doesn’t see the benefits of the high compression, those engines can be made to run very strong with simple changes like injectors and pump work.

 

There are 6 different CPL numbers it could be.

 

I wasn't telling him to change parts. I don't know what he has either, I was just throwing around what someone else could of done to it. No way to know w/o tearing into it or calling the shop

 

QUOTE="Mountainmover, post: 7939570, member: 160234"]Speaking of a 3406. I’ve always heard they are way better at preformance than Cummins. I’ve owned some 3406 trucks but never went wild with upgrades.
What are the bonuses of a 3406 over a big cam Cummins or n14?
I’m guessing Cummins is cheaper up front, good on fuel, and parts are cheap. I guessing 3406 has more cost up front, better stock level torque, better performance potential, and parts are higher?
Downside of Cummins is cam issues and less torque?
Downside of cat is single head that can crack easier?

So, my big cam Cummins nc-315 Brown Engine should go what direction for useable performance? Pull it out and change pistons, head gasket, cam timing and what?
I have low flow cooling. I know that needs to change soon. Works good right now but....
Is my engine a counter sunk liner engine?
1985-1986 freightliner flc120.[/QUOTE]