What does 2" of blowby mean?

Its another way of measuring pressure. 2.08" of water equals about 0.075 psi. No idea if that's within spec or normal though. Have never done a blowby test before.

 

Didnt Detroit Diesel stop doing blowby tests....

they're unreliable......

 

2 inches is about half way to rebuild.
7 inches was my s60 Ddec 5 it still ran great, but used 1 gallon of oil ever 500 miles. My rings were toast.

 

Seems like the Acerts were known for a lot of blowby when the engine was in good condition.

 

I the old days,we used to use a water manometer, to check crankcase pressure.Simple U shaped gauge glass tube,was just a way of checking crankcase pressure vs. atmospheric pressure.How far up the water was pushed was the measurement. Don't rember specs.

 

Rawze has a YouTube video of a homemade one.

 

In the old days of single grade oils,a NTC Cummins overhaul was usually good for 400k. On a fresh Overhaul, I could run from Baltimore to the West Coast and back,no oil use. Second year,out and back,a gallon of oil. Third year,a gallon of oil going out,gallon coming back.Fourth year,gallon,every time you fuel. End of fourth year,time for overhaul again. Oil was expensive, $4.00 a gallon.

 

Didn't think anyone did that anymore in this hi-tech world.