>I've been told a reading of 3.5 oil blow by is good results
>for engine?
>Would appreciate your input.
>
>Thanks
John,
The proper way to check crankcase pressure is with a water or mercury manometer attached to the end of the road draft tube. You ought to ask the tech that gave you the 3.5 number to explain the reading further. Also, you should be able to get the spec number by calling a Cummins Distributor's service department.
The test result should read something like....X.XX" of H20(or HG if a mercury manometer is used) @ XXXXRPM (usually test is done at high idle with no load).
A good manual to have if you get this truck with the M11 is Cummins publication # 3666143-02. This is the truck sized Operation and Maintenance Manual that usually comes with a new unit. I looked through my copy that I keep in the truck, but could not find a crankcase pressure spec.
Rex