A.C. B oil pressure woes

Switching to the paper filter should logically raise it. But logic may not apply.

Stand pipe info correct.

Put a NAPA on mine and it runs at 10# with a little vibration.

• Filter

There are still some NAPA and WIX filters out there, built to the older "rag" style. You can tell them because they have a wooden stick poked up into the fiber filling to keep the passage open until you install it. If you can't see fiber wadding up inside the hole of the filter, don't install it.

AGCO still sells the original style filters but they cost nearly $10. Still cheap compared to loosing an engine.

Both NAPA and WIX stand by their filter design but the flood of ruined engines with their filters still mounted speakes otherwise. The claim is that the oil pressure is determined by the stand pipe but real world experience and tests show differently.

Make sure your filter is not the pleated paper style.

Hope this is your answer.

N - 3 psi
O - 6psi
R - 9 psi
M - 12 psi

and so forth. Remember, this is a bypass filter system - not all of the oil goes through the filter, only a portion. 3 psi at the filter doesn't mean 3 psi through the whole system - it will be somewhat higher. My 1949 B has been running on the "N" or mayeb a little under for a looong time now. It doesn't smoke or use much of any oil (maybe a half-quart in 50 hours or so) so I haven't reid rebuilding it. I'd figure I have some oil pump issues or maybe a bypass valve issue.