'46-98

For the 1946 straight 8 was there a bypass oil filter option, or has anyone modified a full or bypass system? I have a fairly new rebuilt engine and was thinking a little fitration is better than nothing.

Regards, Nick

Tedd Thompson

I could be wrong on this but wasn't the oil filter a add on dealer supplied item?.... Tedd

coldwar

We are conditioned to see oil filters on automotive engines, and are not comfortable when the original design did not include one, or one as standard equipment. One of the ideas of filtration in automotive engines is (was) extending useful oil service life to something like 3000 mile service intervals. I changed the oil on my 1952 Pontiac I-8 which had no filter at 1000 mile intervals, that same engine in original condition I owned 35 years ago is still running great today with no smoke and great oil pressure. This is one example - Is it really worth the work and adaptation for a car driven seasonally? Five quarts of high zinc/phosphorus oil is about $40.

Ozzie

The Oldsmobile Chassis Parts Book shows group 1.836, Element, Engine Oil Filter, 1939-1947 All; type C-112, part number 5570073 (Another number was shown for 1948.)
That makes me think that there was one available for 1946. Rigging a full flow might take some doing, but a bypass system could possibly be easily done even if it's not "original". All you need is a tap into the oil gallery. The return line can go to the pan or valve cover. My 1962 AMC came with a bypass system which I converted to full flow. It was relatively easy because the factory produced a full flow oil pump in 1965 which could be utilized with just a slight modification. Some of the bypass filter elements had tighter media than the full flow elements.

Fusick sells the filter element (they call it P-112) for $18.50 + shipping.

The Wix number "might" be 51001. Check their website for the dimensions.

'46-98

Thanks for the replies. I'm leaning to Coldwar's suggestion. Changing the oil more frequently, I usually change the oil 1500-2000 mile range on my other bypass equiped cars as i'm mainly back road highway driving.

47 Convertible

I'm old enough to remember pre oil filter days, partial flow filters--both factory and after market and eventually all manufacturers moving to full flow oil filters. In the 1950s I worked after school in a service station and it was common about every 3rd or 4th oil change to "flush" the engine with a mix of 1 quart of oil and 3 quarts of solvent after draining the old oil. We put the drain plug back in, put the flush mix in and started and ran the engine a little above idle speed for about 30 seconds. Shut off engine, drained oil which was always black with contamination and then poured another quart or so of solvent through oil fill and just let it drain without starting the engine. Put drain plug back in and fill with recommended motor oil (usually 30W in summer and 10 or 20 W in winter). Multi viscosity oil like 10-30 W were just being introduced at that time so most ran single weight oil that came out of a bulk container in the lube room of the service station.

The practice died out as factory installed oil filtration became more common. Even with these accepted practices like after market filters and engine flush, engines seldom went more than 80,000 miles before needing a "ring and valve" job or complete overhaul. Lubricants, filtration, assembly clearances and metallurgy just weren't that great 60 or 70 years ago.
Jerry

Powermat

Did you end up getting one of these filters Nick?? I'm after one of these for my '41 straight eight and I'd imagine it's the same as what you're after.
pretty sure they were a dealer option as I've seen many photos of '40s olds with exactly the same filter assy

'46-98

I have decide not to go with the filter as it looked like they were usually mounted in front of the carb. Since my car has been modified with a modern twin carb design I decided I did not want to clutter the intake area.My engine has been rebuilt and running detergent oils now,so I will just change the oil more frequently. I have the by pass filters on some of my old Mopars, not sure how much they really help, but some filtration has to be better than nothing.