Remote oil filter fitting re size
- Thread starter Rudolph
- Start date
JSeery
Member Emeritus
Not sure what the top and side threaded holes refers to. To me, they are both on top, the original oil pressure gauge outlet (2 outlets, one vertical and one horizonal) and the one you drill nearer to the center on the engine.
If you are referring to the two different holes drilled into the original oil pressure gauge outlet, they both go into the same passageway and only one would connect to an external full flow or 95% flow filter. The second of the pair is for an oil pressure gauge fitting and there would be no reason to enlarge it.
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Ronnieroadster
Well-known member
To answer your question.
If your block is a 59A or 8BA the pipe thread size increases to 3/8 from the present Ford size which is 1/4 pipe. However if you have the earlier block pre 1946 going up to the 3/8 pipe size would be hard to do since the raised casting area for the oil sender and oil filter return line is very small in diameter with only enough material for the original size 1/4 pipe thread. Using only the smaller 1/4 pipe thread size is to small for the oil filter conversion.
Ronnieroadster
Ronnieroadster
Well-known member
The important part of this conversion is to not reduce the flow by using fittings that are much smaller diameter that the diameter of the main oil passage in the block. The Ford flathead block oil system cross passage is .421 in diameter in every block I have measured. When doing the conversion using 3/8 pipe thread size fittings they can be opened up to the .421 diameter. That's what I always do to any fittings I use when doing this conversion. The way I see it is the safest way to modify the oil system. Good luck.
Rudolph
Senior Member
I will do what you say, I had a look at my block and I think the horizontal hole below the oil sender will drill out and take a 3/8 thread ok, I will try to get steel fittings
Rudolph
Senior Member
this is interesting, some of the carrier motors had a plug witch extended into the gallery to plug it. http://www.mapleleafup.net/forums/showthread.php?t=20460
Aarongriffey
Well-known member
Ok, I’ll bite, what is a carrier?
Rudolph
Senior Member
This thing, you would be speaking German if it wasn’t for them, actually the US soldiers thought they were ****, there are 1000s of them here still they had Mercury engines.
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Automotive Stud
Well-known member
Just a piece of advice for anyone thinking of doing the full filter modification, be very careful when drilling the block. My friend has a rebuilt motor that was modified that way. Everything looked good prior to installation, but when the block was drilled for the full filter modification the drill got into the back wall of the block, making it paper thin. Under oil pressure it gave when the car was running on break in, pouring oil out of the bellhousing.
rotorwrench
Well-known member
The universal carriers had an oil cooler set up and filter so they were set up for the pressure flow out and back. This is a link for the way they were set up.
http://www.mapleleafup.net/forums/showthread.php?t=20460
There are threads about this on this forum if you get a good search string. Folks have to be cautious to make certain that the oil flows properly so as not to starve the engine of oil. More than one owner burned up there bearings due to the lack of knowledge on these systems.
Technically it's not really a full flow system the way the rear main gets oiled but it gives enough bypass to do an excellent job of filtering as long as the filter set up is good quality.
http://www.mapleleafup.net/forums/showthread.php?t=20460
There are threads about this on this forum if you get a good search string. Folks have to be cautious to make certain that the oil flows properly so as not to starve the engine of oil. More than one owner burned up there bearings due to the lack of knowledge on these systems.
Technically it's not really a full flow system the way the rear main gets oiled but it gives enough bypass to do an excellent job of filtering as long as the filter set up is good quality.
rotorwrench
Well-known member
That may not be a bad idea. I've done resizing of NPT fittings before and I've also installed heli-coils in some aircraft applications. When going larger a person sometimes doesn't realize how much larger they are until you have one in hand. I drill to the minimum thread valley sizing at the start of the taper. I then use a tapered reamer to open it up for even use of an NPT tap. A lot of care has to be taken not to enlarge it too much. If you ever do one in cast iron, you will find out how fun that can be. Aluminum is a lot easier but regardless of material, they can be tricky. I use mostly AN fittings. They are available in anodized aluminum, cad plated steel, and stainless steel. The price will rise in that same order. Many times brass can be sourced and there is nothing wrong with using brass if it will do what you want it to.
There is a lot of stress on a tapered type fitting at installation and removal so don't drill them any farther than you have to. A person can also source straight thread type fittings and use a spot facer to finish the boss for a small cross section O-ring lock-o-seal and nut to seal it up. These are custom applications in the aircraft industry but they are out there.
Flatheads didn't really need a lot of oil pressure to function. The old universal carriers didn't go real fast either. They were more like a fast tractor than a jeep. They could likely set there and idle for quite a while unless the air temp was too hot. 1/4" NPT fittings are usually used with 3/8" size tubing in aviation so it would only act as an orifice to slow the flow a bit.
There is a lot of stress on a tapered type fitting at installation and removal so don't drill them any farther than you have to. A person can also source straight thread type fittings and use a spot facer to finish the boss for a small cross section O-ring lock-o-seal and nut to seal it up. These are custom applications in the aircraft industry but they are out there.
Flatheads didn't really need a lot of oil pressure to function. The old universal carriers didn't go real fast either. They were more like a fast tractor than a jeep. They could likely set there and idle for quite a while unless the air temp was too hot. 1/4" NPT fittings are usually used with 3/8" size tubing in aviation so it would only act as an orifice to slow the flow a bit.
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glennpm
Well-known member
This made me curious on the real differences between using 1/4" or 3/8"NPT fittings.
ID for 1/4" = .36
ID for 3/8" = .42 (same as flathead oil system
root diameter of 1/4" is about .48 at end of taper, so not real safe to drill out to .42. .40 would be okay.
The other thing to consider is that if using 1/4"NPT fittings, the velocity and pressure drop for the 2 effective fitting's length would have a very small effect upon the flathead oil system and large diameter oil lines to the external filter.
Glenn
ID for 1/4" = .36
ID for 3/8" = .42 (same as flathead oil system
root diameter of 1/4" is about .48 at end of taper, so not real safe to drill out to .42. .40 would be okay.
The other thing to consider is that if using 1/4"NPT fittings, the velocity and pressure drop for the 2 effective fitting's length would have a very small effect upon the flathead oil system and large diameter oil lines to the external filter.
Glenn
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Rudolph
Senior Member
I am actually not going to drill the block out for 3/8 I will drill the 1/4 fittings a little bit, the outlet in the oil pump is very small and this engine was made with a remote filter and oil cooler, it’s going to have way less pipelines than factory.
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glennpm
Well-known member
Yes, a good plan.
And for those that want to prove/disprove this here you go ;-)
https://www.engineersedge.com/fluid_flow/pressure_drop/pressure_drop.htm
Hint: 2 losses for entrance to each fitting, a sharp decrease; 2 for large increases leaving the fittings and 2 short lengths of diameter decrease in the middle of the fittings
And for those that want to prove/disprove this here you go ;-)
https://www.engineersedge.com/fluid_flow/pressure_drop/pressure_drop.htm
Hint: 2 losses for entrance to each fitting, a sharp decrease; 2 for large increases leaving the fittings and 2 short lengths of diameter decrease in the middle of the fittings
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Zeke3
Well-known member
Thanks Glenn, I thought I was back in Fluids class.