Dyno's
 

I have seen G-man write that you can get a decent truck for about 20 grand and some with rebuilds, and I have been checking and he is right. I know not to buy a truck without getting a dyno, my question being! What exactly does a dyno tell me?

Basically a Dyno Test is for Tuning your engine
checks oil pressure-Horsepower-and blow by
Test is under load

Re: Dyno's
 

As yoopr stated ; a dynamometer is used to place an engine under a load (simulate a hard pull) and then measure horsepower potential.

HP to the ground ; chassis dyno.

Flywheel HP ; engine dyno.

Most dyno's can gather a whole bunch of data. It depends on what you want to spend for the Dyno run. When buying a used truck you would want a power run with blowby and horsepower. You should also make them give you a print out with ecm miles if it is an electronic engine.

I am looking at a truck with C-12. Need help reading Dyno.
As I put in my other post. It has .2 - 1% blow by. Is this decent for a 2003 with 500K miles. At 1550 rpm it had 371hp & .775 blow by. 37.5 psi oil pressure and 20.8 lbs of boost.

Anyone want to throw in here an answer to "what is blowby?" I'm not sure what this means.

When you piston rings or cylinder liners wear, a small amount of compression will get past the rings and go into your crank case. And this is called blow by. This is ussaully piped out of the valve cover and then headed down towards the ground with a steel pipe and then a rubber hose.

a small amount of blow-by is normal

the rubber hose is often added by... someone after it leaves the manufacturer. the extra length can pull a lower than desired crankcase pressure that can cause a sort of "backdraft" intermittently which causes road debris ingestion..... not recommended. i've seen dusted engines refused warranty due to this add-on..... course, i've also seen the hoses added by certified dealers as a method of getting the blow-by oil drip off the i-beam, so...................

10-4.

When is a good time to get a dyno run on truck.I have a 2000 Frtliner with a Det.470 with 812,000 mileage. No problem out of truck just would like to know if I should have it done.