Hey guy and gals, I just finished a fun little experiment.
I fabricated a polyethylene washer just the right size to completely block off all the inlet holes on the oil filter. (using a new clean, dry filter, of course,,).
here is the cool part. I started the engine ('99 Bonneville 3800 vin K) and make careful reading of the oil pressure: exactly 60 psi, as close as possible to read on the factory gage, at idle. (-the wife had just returned from shopping, and the engine was at normal operating temp.) Shut it off, removed the filter, installed the block-off washer, reinstalled the filter, and restarted the engine.
-care to guess what the outcome was
Well, how about this: With the flow through the filter totally blocked off, the oil pressure once again read exactly 60 psi.
So, once and for all, no one needs to worry about their oil pressure being affected by any one oil filter, versus any other.
(Darn, once again the engine manufacturer'* engineering data proves that the basic laws of science are still working)
Oh, by the way, a sort of "what it'* worth: For years now, I have used ONE filter to fit MANY different engines. That is the WIX # 51036, or NAPA gold 1036, or even the NAPA Silver 21036. I use it on 1990 Chevy 350 4X4, 1987 Chevy Astro Van 4.3L, 1987 Olds 88 3.8L, 1984 Olds Cierra (sp?) 2.5L, 1994 Olds 88 3.8L, 1990 GMC 4x4 350, 1993 Buick LaSabre 3800, and now this 1999 Bonneville.
One of the reasons it works on all these, is that it is the larger 1 quart filter with about twice the square inches of filter media compared to the little one, has a very well designed "anti-drain back" valve (important on some engines designs, and a good idea for all applications), has the correct thread size, the correct gasket size, and has excellent clearances on all applications.
So, what do you think of that ??