90% Oil Filtering Fitting

Not all of even the later blocks have the flat spot cast into them, it does not make any difference in the modification.
 
Hey all, have any of you done this on a 21 stud engine? I have a 36 and was reading the past threads and after looking at my block on the stand it does not have the convenient flat spot in the casting like the later engines. Finding the oil passage is easy but I am concerned that due to the curvature of the casting in that area I will not have enough material depth to get a good set of threads cut for the second fitting.

I have installed a Mark Kerby full flow system on a 35 21 stud engine. Altough Mark is no longer selling these, somebody has picked up his design and is selling it today. Not sure who that is. You could also do the BillM design as he mentions here on this thread. You don't need to have that flat spot on your block and you will have enough wall thickness in the bell area for threads. Here is an instuction file that tells you how to locate the spot to drill and tap if you do or do not have the flat spot. If I wanted to put an oil filter system on an early 21 stud engine today, I would use the 95% FF system.
Here is an article on this taken from Bill B's Tecno Site:
http://www.flatheadv8.org/filter.htm
 
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OK, I know that filtered oil is better, but is this necessary? Say if one is diligent and changes the oil regularly (say every 1,000 to 1,500 miles).
 
There is a Canadian setup that used an external "H" type of fitting that is probably what you are thinking of. It also has a pressure relief valve in it. I have no idea how it would work if the diagrams of it are correct because it also allows a direct bypass through the block passages, but never really worried about it either!


The "H" fitting shown on Meric 42 post of the Canadian military full-flow is the the filter by-pass needed for cold start oil circulation. The fitting that blocks the horizontal passage has an integral 1.25" thinwall brass tube that extends down past the horizontal connecting passage. The top of that fitting connects the 3/8" ID line to the filter. This same fitting was used on the post-war Ford Canada option that used 3/8" ID hard lines from '46 to '48 and 3/8" ID hose on the '49 '51 version.
This fitting would always have to be removed to plug the block openings to run without filter, or change back to the bypass type. No surprise grub screw that might be missed later. ..B.
 
The "H" fitting shown on Meric 42 post of the Canadian military full-flow is the the filter by-pass needed for cold start oil circulation. The fitting that blocks the horizontal passage has an integral 1.25" thinwall brass tube that extends down past the horizontal connecting passage. The top of that fitting connects the 3/8" ID line to the filter. This same fitting was used on the post-war Ford Canada option that used 3/8" ID hard lines from '46 to '48 and 3/8" ID hose on the '49 '51 version.
This fitting would always have to be removed to plug the block openings to run without filter, or change back to the bypass type. No surprise grub screw that might be missed later. ..B.

Thanks for the input! I think I can see the faint lines for the tube you are describing on the line drawing now. I knew it would not work if it was open, but just didn't look close enough to see the faint lines.
 
many of the full flow wartime engines were for Bren carriers which had an oil cooler rather than a full flow filter...a little flathead pulling around an AFV had to run at full throttle most of the time. Many Canadian built trucks and gun tractors had the filters and PCV setups.
As far as I can tell, USA wartime engine picked up the little boss as part of assuring interchangeability of resources, since some USA flatheads were fed into Canadian production during the war.
By the way...if you read through Ford's own 1937-48 engine rebuild book, you will note that the pictures are of a wartime engine that has full flow...you can see the three fittings in one of the pictures.
 
OK, I know that filtered oil is better, but is this necessary? Say if one is diligent and changes the oil regularly (say every 1,000 to 1,500 miles).

In my opinion, no it's not necessary. But each to their own I spose.
Im gonna be using one on my truck when it gets a fresher engine. But only as I have the Canadian military bits (except the H bypass bit, but some/lots of spin on filters have one built in, so I won't pay it any mind) The stuff I have I pulled of engines I've rebuilt and they didn't want them bits. This is the style with a thinwall fitting that covers the hole, not the grub screw style. I also have the Donaldson crankcase ventilator (PCV) that I may fit if it don't bugger about with the Southwind heater.
If I didn't have the bits to hand, I'd use the stock Ford oil filter, bypass style. It worked for years and that's ok by me.
Do folk really change oil every 1000 miles? If you do 2000 miles a year, that maybe ok, but if you do proper mileage it seems excessive to me.
Martin.
 
In my opinion, no it's not necessary. But each to their own I spose.
Im gonna be using one on my truck when it gets a fresher engine. But only as I have the Canadian military bits (except the H bypass bit, but some/lots of spin on filters have one built in, so I won't pay it any mind) The stuff I have I pulled of engines I've rebuilt and they didn't want them bits. This is the style with a thinwall fitting that covers the hole, not the grub screw style. I also have the Donaldson crankcase ventilator (PCV) that I may fit if it don't bugger about with the Southwind heater.
If I didn't have the bits to hand, I'd use the stock Ford oil filter, bypass style. It worked for years and that's ok by me.
Do folk really change oil every 1000 miles? If you do 2000 miles a year, that maybe ok, but if you do proper mileage it seems excessive to me.
Martin.

I would assume 1,000-2,000 miles a season (average) and change it once it year.
 
OK, I know that filtered oil is better, but is this necessary? Say if one is diligent and changes the oil regularly (say every 1,000 to 1,500 miles).

Is an oil filtering system necessary on our modern cars? I don't recall seeing any cars built since the 50's that did not have an oil filtering system. Do we really need it if we routinely change the oil at maybe some logical interval? Would we even think about eliminating the oil filter and saving on the cost of buying maybe 3 to 4 oil filters each year?
 
Is an oil filtering system necessary on our modern cars? I don't recall seeing any cars built since the 50's that did not have an oil filtering system. Do we really need it if we routinely change the oil at maybe some logical interval? Would we even think about eliminating the oil filter and saving on the cost of buying maybe 3 to 4 oil filters each year?

Modern engines to a flathead are an apples to pears comparison. Look at how many Briggs & Straton engines survived without a filter. I have one still going strong after 35 years. Let's face it, flathead isn't too far removed from a B&S motor.
 
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Modern engines to a flathead are an apples to pears comparison. Look at how many Briggs & Straton engines survived without a filter. I have one still going strong after 35 years. Let's face it, flathead isn't too far removed from a B&S motor.

I disagree Tim...how often do you change the oil in yuor lawan mower...say...once a year?

How many hours of running said mower, does that translate.....

So say I mow my lawn once a week from spring through fall...I have 35-40 hours on the engine.

Heck, you could do that in a automobile in a week.

Other issue (as was brought up above, not by you Tim) is modern vehicles are fuel injected, the fuel entering the engine over the past 15 years or so, is precise, as is the timing, load adjustments, etc...nothing like even the "best" carb'ed engine could ever achieve...which lead to fuel fouled oil eventually.

Even if driving a carb'ed engine under ideal, no dirt, dust environment, the oil will contaminate and needs to be serviced.
 
I'd like to add some weight to the pro oil filter side. Just cus of the devil's ardvercut (sp?) The Ford Popular (Anglia) 103E, came stock over here with no air filter, just a lid over the carb, and no oil filter up to 1959. The engine life expectancy was about 30000 miles before major rebuild, including re bore and crank grind.
For the modern properly filtered engine, 100 000 miles is a walk in the park.
I know oils are better, running temperature is higher and proper pcv systems do a chunk of the longevity job, filtering does its fair share too.
Martin.
 
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