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Hi, as the 1931 has bypass oil filtration, I am considering what to do. The old disposable filter cartridge is obsolete although there are a few around. I wonder what the group thinks about either a vintage cartridge filter housing or maybe a Franz bypass filter (which is still available new, by the way)?
You can buy modern reproduction units with a spin on oil filter inside. The first purchase is expensive, then three dollars a oil change after that. Cislak has them in stock, and they were on display at Hershey. They are very nice.
A word of caution about NOS filters. Do not use NOS filters. These filters have cotton in the element. This deteriorates with age and can come of in the oil causing a bad problem.
Paul
I specifically recall the Franz filters get much smaller particles than a full-flow filter and they used to use a roll of TP. They have purpose-made filter elements now though. There have been many aftermarket filter devices over the years. As my car will be a driver I am not ashamed to use a full-flow filter.
Hi Randy. BE CAREFULL !!
Your 1931 engine has a port on the main oil gallery [that supplies oil to the entire engine]. This port goes to the bypass oil filter, the oil passes through the filter element then the oil just drains back into the crankcase and oil pan.
The original filters had either a built in restriction-office or a very dense filter material. What this did was to restrict the volume of oil being bled from the engine oil system to be simply returned to the oil pan.
There have been several engines damaged by modern filters installed that do not have any flow restrictions, and the engine starved for oil. A modern full flow oil filter is necessarily a low-restriction filter, since all engine oil has to pass through the filter, then into the engine to lubricate the bearings and other internal parts.
Your statement about using a full-flow oil filter raised a red flag for me. The 1931 engine does not have ports in the oil galleries to use a full flow oil filter. !!
The first 8cyl engine that has ports for full-flow oil filtration is a 1933 engine. On this engine block, there is a large port coming out of the side of the engine block, just 2 or 3 inches above the oil pan. This port carries ALL the oil from the oil pump, the normal passageway is not drilled all the way through to the main oil gallery. The oil is passed through a heat exchanger [either heats the oil, or cools the oil] then the oil passes through a full flow oil filter, then it returns to the main oil gallery to lubricate the engine. NOTE: No oil is returned to the oil pan! ALL the oil is filtered then returned to the lubrication main-gallery. There is no loss of volume or oil pressure to the engine bearings.
So: if you choose to use a modern full-flow oil filter as your by-pass oil filter, you MUST put in a restriction in the plumbing or you will lose a lot of oil pressure and volume that your engine bearings need to survive.
In the engines I’ve owned or worked on that have a bypass filter, i have filled the end of one of the brass oil supply fittings with solder, then drilled a 1/16″ hole through the plug of solder. This size hole allows enough volume of oil to be filtered to keep the oil clean, yet not too much volume that would drop oil pressure and supply to the engine bearings.
A bypass oil filtration system works very well, but it’s name tells the story: the oil ‘bypasses’ the lubrication system in order to go through the filter.
Greg Long
As usual, Greg is 100 percent correct.
Ed,
Based on what Greg just wrote, I was curious about the modern reproduction units that use modern spin on oil filter inside. Do these modern reproductions have some sort of flow restriction since they use a modern full-flow oil filter?
Robert
You place the flow restriction in the fitting on the oil filter, on the inlet side of course. John Cislak makes the filters. Look in thr last PAS publication, they were for sale in it. Ed
Thanks, Greg, you answered my next question in advance. I did not know if the restriction was on the (disposable) filter or in the fittings, but I have not found one in the fittings.
A vendor offers a very nice bypass filter replacement for a Ford 8n tractor, and it does have an orifice. I do not trust NOS filters so I am exploring what to do here. I have seen the hidden conversions, but no information about if they have an origice.
An update to my investigation of the bypass oil filtration issue:
I examined the copper piping which served as the oil inlet and outlet on my ’31. There were no orifices, only normal brass tube fittings. I then checked the filter element: an AC P-21 painted blue with red logo, etc. and stamped INLET and OUTLET at the appropriate end. I poured thin solvent into each end and it would flow freely into the filter at the inlet port, but I could get practically none to pass into the outlet port. Then I poured about two cups into the inlet; after a few seconds passed the oil-solvent mix began to dribble out the outlet port. I turned the filter over and oil would pour out the inlet port. It became clear that the filter itself has a restriction on the outlet side.
Next I plan to cut the filter open to see what’s inside.
The factory filter set up was restricted in the inlet fitting. It was machined and produced as one would expect, hard to find item today, so soldering in a pill and drilling it out is reasonable.
Gentlemen,
Has anyone tried a WIX brand 51100 model cartridge to see if this will fit the original bypass filter system for a ’29? It seems to have the correct interior diameter and is close, but just a bit shorter than the AC brand P115 that came with my engine.
Bob