gearchanges to around 1600 MAX
Cruise rpms in the 1400's range
that should keep you fairly good in mielage.

My old one dyno'd 395 hp to the tyres, it had some codes in it ( dont know what )
apparently average was 360-370.
The program was 435hp 1650tq.

Great little engine, i do miss it. Better to drive than the signature i have now, even tho the signature does pull well.

Yeah, noticed it wanted to shift right at 1450. The clutch has less than 100k on it & the trans was rebuilt at the same time, so still pretty tight. Think they said a new rear seal was put on the motor when the trans was dropped out.

The guy that traded it in, picked up a '07 T800 with a C-13 & said the 12 felt stronger. Though he had only ran that truck for a week at the time.

Originally Posted by LBZ

The guy that traded it in, picked up a '07 T800 with a C-13 & said the 12 felt stronger. Though he had only ran that truck for a week at the time.

I think that has a lot to do with the way the Acert's feel. They're a little slower taking off but side by side on a hill there isn't much difference. C12's are mean little motors though. I've noticed after jumping out of a 6NZ into a identical truck with a MXS Acert. The 6nz screams but the trucks still top the hill about the same speed.

Put a C12 up against an M11 Cummins and it's laughable. The M11 might as well say Briggs & Stratton.

You really want to have good coolant in those things, they have a lot of aluminum. I would stay away from anything with DCA in it either NOAT or DEX-cool is great, and a coolant filter is also highly recommended. Get a valve set, done get the CAC tested, Get a set of bearing in it, they are cheap and on that motor easy. Just a thought!

Originally Posted by LBZ

Anyone know how to read a dyno report? I understand the first one with the graph, but curious what the allowances or specs are for the blow by & some other things on the second pdf.

Any input is much appreciated!

LBZ, a lot of guys run them around here,tough little motors,from what they say.Wheathauler runs one and he just had it put on the dyno recently,i bet he could help with info,i think farmermatt has a c12 also

I called Altorfer CAT today & asked about the blow by specs. According to whoever I got there, said to take the stamped HP number multiply by 1.5 & if the blow by number is below that it is still within spec.(430 HP x 1.5 = 645) That was for the loaded test, empty is at .4 if I remember correctly.

I was looking at buying a 99 western star with c-12 cat and 13 speed, was also wondering what anyone had to say about them good or bad and how they are on fuel mileage? Does anyone know if there is anything that can be done to improve performance without hurting engine?