Remote oil filter fitting re size

[Rudolph]

hello, I am doing the mod of installing a plug inbtween the oil galleries but I want to drill out both the side and top threaded holes for bigger fittings, what’s a good size to go to? Might be hard to go much bigger on the raised boss one.

[JSeery]

Originally Posted by Rudolph

hello, I am doing the mod of installing a plug inbtween the oil galleries but I want to drill out both the side and top threaded holes for bigger fittings, what’s a good size to go to? Might be hard to go much bigger on the raised boss one.

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.

[Ronnieroadster]

Originally Posted by Rudolph

hello, I am doing the mod of installing a plug inbtween the oil galleries but I want to drill out both the side and top threaded holes for bigger fittings, what’s a good size to go to? Might be hard to go much bigger on the raised boss one.

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

[Rudolph]

I have a 1942 block, yes I don’t want to enlarge the oil pressure sender hole just the one on the same boss witch is horizontal and the one on the bell housing above the boss

[Rudolph]

I think I have to get steel fittings made and drill them to the biggest size witch I can

[Rudolph]

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A small reduction in size will be ok because it’s not going to be the length of the whole oil line and the outlet in the pump is not huge

[Ronnieroadster]

Originally Posted by Rudolph

A small reduction in size will be ok because it’s not going to be the length of the whole oil line and the outlet in the pump is not huge

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]

Originally Posted by Ronnieroadster

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.

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]

this is interesting, some of the carrier motors had a plug witch extended into the gallery to plug it. http://www.mapleleafup.net/forums/sh...ad.php?t=20460

[Brian]

Rudi, I do it the same as Ronnie, follow his advice. Just be aware that when screwing the fitting into the outermost hole, there is not a lot of meat, do not overtighten the fitting or you'll crack the casting.

[Aarongriffey]

Ok, I’ll bite, what is a carrier?

[Rudolph]

Originally Posted by Aarongriffey

Ok, I’ll bite, what is a carrier?

This thing, you would be speaking German if it wasn’t for them, actually the US soldiers thought they were shit, there are 1000s of them here still they had Mercury engines.

[Automotive Stud]

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]

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/sh...ad.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.

[Rudolph]

My engine is a universal carrier engine with the extra oil hole, they didn’t seem worried about sending the oil through 1/4” fittings and lots of oil line and a cooler and a filter from factory, I am thinking I should just use the 1/4” fittings and drill them out?

[rotorwrench]

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.

[glennpm]

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

[Rudolph]

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.

[glennpm]

Yes, a good plan.


And for those that want to prove/disprove this here you go ;-)


https://www.engineersedge.com/fluid_...ssure_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 :-)

[Zeke3]

Originally Posted by glennpm

Yes, a good plan.


And for those that want to prove/disprove this here you go ;-)


https://www.engineersedge.com/fluid_...ssure_drop.htm

Thanks Glenn, I thought I was back in Fluids class.