Compression test

[dhirocz]

Anyone ever run a compression test on an 871? I just finished replacing my compressor (noisy), rebuilding the P/S pump and a number of gaskets. I'm still getting some signs of blowby in the crankcase, such as visible oil vapor out of the breather tube at hot idle and oil vapor smell while driving.

730k miles, had @m*m^2, 6 dimes and a bearing roll when the flat cam was fixed at 685k. It's also running the maintenance free breather element on it.

It seems to be doing it less since swapping compressors, which tells me the compressor might have been pressurizing the crankcase perhaps...but I am still getting heavy oil stains out of the breather tube anytime I'm loaded. It's no longer bleeding oil from everywhere like it was before.

I just want to make sure I'm not overlooking something and driving it like that unnecessarily. I expect there to be signs of wear, and am bringing to back to Savannah to do a complete inframe this summer.

A compression test will at least allow me to verify that it isnt something else I've overlooked. If not, would increasing the amount of gear oil I'm running help? I've also considered that the rings could be caked in junk.