Oil filters on flatheads

NealinCA said:
Does anyone have a great trick to mounting a stock type oil filter on aftermarket finned aluminum heads?
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Offenhauser used to make a part just for this. It was made of aluminum and bolted to the head bolts, the other side had three tapped holes that picked up the mounting points of a standard 8BA filter. I had one I picked up at the Chickashaw swap meet about 20 years ago. Unfortunately, I sold it several years ago. You might want to go to the "Exeter Speed Shop" web site where they have the entire Offenhauser catalog in pdf format. I think there is a picture of one there which may help in find one or perhaps making an analog.
 
Another trick is long nuts (coupling nuts) used as spacers and a std filter that fits to the headbolts.
They come in stainless if you want it nice and shiny.
 
supereal said:
If you believe that the bypass filter isn't effective, just forget to tighten the cap when you change the element and observe the oil shower! Don't ask me how I know that! I buy the elements at a local NAPA store where they still stock them for the Ford tractor owners Old Henry Ford didn't believe in filters. That is why the intake of the Model A carb points toward the rear of the vehicle. He thought that the plentiful dust and dirt on the old roads wouldn't enter the carb as long as the car was moving forward!
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That Henry Ford "quote" sounds bogus! Do you have a reliable source for it?
 
On Ford's (the company) view of bypass filters, the original manual for my 1940 states to change the oil every 2,000 miles if the engine does not have a filter. On filter equipped engines a 5,000 mile change interval is recommended, and the filter element changed every 10,000 miles.
 
I wrote the original post. I think I am convinced. This winter I will be re-installing the Ford bi-pass filter on my one flathead that does not have one. Many thanks for all of the comments and ideas. There is lots of wisdom and knowledge at the Ford Barn - great group!

Bill in Conn.
 
One thing to keep in mind is that a by-pass filter can filter to a much smaller micron size compared to a full-flow filter. A lot of modern diesels use by-pass filters for that reason.
 
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JSeery said:
One thing to keep in mind is that a by-pass filter can filter to a much smaller micron size compared to a full-flow filter. A lot of modern diesels use by-pass filters for that reason.
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Also keep in mind that the by-pass filters used on diesels are capable of a smaller micron size than the commonly used Ford replacement by-pass filters.
 
What is the filtration size on the flathead filters?

Is the Wix 51006/NAPA 1006 a good number? It is rated at 32 micron.
 
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Bypass filters, by their nature, are able to slow down the flow of oil as the filters load up, without affecting oil flow to the bearings. Modern filters must pass oil without a major drop in pressure/volume, so the finer particles are passed, and as they load up, their safety valves open to pass without filtration at all. The bypass filters not only screen out finer particles, but they require only 10 miles of driving for about 95% of all the oil to pass through the filter at least once. A feature that all oil filters share is the added total volume of oil in the system, which is helpful in keeping the engine cool, as well as preventing the oil itself from breaking down from excess heat. All cars today need a filter of some kind, due to the modern detergent oil suspending particles rather than allowing them to drop out overnight, becoming sludge in valve galleys and oil pans.
 
JSeery said:
What is the filtration size on the flathead filters?

Is the Wix 51006/NAPA 1006 a good number? It is rated at 32 micron.
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Those are the normally installed replacement filters. Don't know what the micron rating is but have heard from 10 to 25 micron.
I am running an Amsoil by-pass filter rated in the 2-3 micron range, same rating as the ones used on the diesels.
In a measured test at idle speed the filter passed 5 Qts. of oil in 11 minutes.
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51 MERC-CT said:
Those are the normally installed replacement filters. Don't know what the micron rating is but have heard from 10 to 25 micron.
I am running an Amsoil by-pass filter rated in the 2-3 micron range, same rating as the ones used on the diesels.
In a measured test at idle speed the filter passed 5 Qts. of oil in 11 minutes.

so, at cruising speed, about 4+ times the volume? That sounds roughly equivalent to 20+ qts filtered to attain the 95% in 10 miles of cruising. This is sounding so good, I wonder what advantage there could be to use 100% filtered on modern cars?
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ford38v8 said:
51 MERC-CT said:
Those are the normally installed replacement filters. Don't know what the micron rating is but have heard from 10 to 25 micron.
I am running an Amsoil by-pass filter rated in the 2-3 micron range, same rating as the ones used on the diesels.
In a measured test at idle speed the filter passed 5 Qts. of oil in 11 minutes.

so, at cruising speed, about 4+ times the volume? That sounds roughly equivalent to 20+ qts filtered to attain the 95% in 10 miles of cruising. This is sounding so good, I wonder what advantage there could be to use 100% filtered on modern cars?
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The test was done with the engine idling with oil pressure at appox. 20#.
The .060 dia. restriction hole determines how much volume is delivered at what oil pressure.
At a higher oil pressure there may be an increased percentage of volume, but not by a factor of 4 as you speculate.
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The debate to use an oil filter, or not, on a flathead engine will probably never end. Regardless of what Henry Ford did in the early days of his Flathead powered vehicles, in my way of thinking, how many modern gas or diesel engine vehicles are being produced today without an oil filter? It just makes good sense to me, if I'm working on one of my Flathead engines, and have the ability to add an oil filtering system, I'm going to do it.
 
For what its worth, my '47 never had a filter. It was rebuilt I don't know how many years age, now has 35,000 on rebuild, doesn't leak or burn oil, 70 lbs at cold idle/20 at hot idle, use 10w-30 and change every 1,000 miles.
 
I'm with "JM" on this. I have just finished my 258' rebuild and I am going to look into one of those Amsoil filters for it. They look to me to be the ideal filter for these engines with the finer filter and the volume "51 MERC-CT" has posted, especially the way these cars are used. I will keep the present stock setup on my '51 Ford.
 
Legend has it modern oils do not break down with heat nearly as fast as old oil does.
The important part is to keep your oil clean, you could reduce the changes to 20-50,000 miles and only replace the filter, if you could filter it finely enough! (Change the filter on a modern car every 1,000 KMs and see how long the oil lasts.) A bypass filter would be a great asset to modern engines.

I'll let you guy figure out how to do that.
 
dumb person said:
Legend has it modern oils do not break down with heat nearly as fast as old oil does.
The important part is to keep your oil clean, you could reduce the changes to 20-50,000 miles and only replace the filter, if you could filter it finely enough! (Change the filter on a modern car every 1,000 KMs and see how long the oil lasts.) A bypass filter would be a great asset to modern engines.

I'll let you guy figure out how to do that.
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One way to do it is with a Frantz or similar type add-on filter. My dad sold them in the fifties and sixties and always added one to each new Oldsmobile he bought. Each one came with two tags. The first was like a regular old style "oil change tag" you used to stick on the door jamb. The second was the same format, but made of blotting paper and was divided up into several segments. You were to touch your dipstick into the corresponding spot every 200 miles after installing the Frantz filter. The oil would be absorbed by the blotting paper, and would show how "dirty" it was. It was amazing to watch the spots get lighter and lighter with each 200 miles that passed. It made me a believer.
 
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