1939 Ford flathead 59AB help
 

Can anyone give me info on the main bearing oil tube. This is the small tube that is 5/16 or 3/8 OD and has a bend in it . My buddy called and his is missing on his motor and ready to put the pan on and motor in. He tried to call a few places and no one had one including me. I figure if I get some more information on it I can machine him one. I dont have one to look at or measure. So if anyone has this info I would appreciate it. Thank you and happy Motoring

Re: 1939 Ford flathead 59AB help
 

Also if anyone has a extra I can buy or borrow so I can machine a few at the shop. Thank you

Re: 1939 Ford flathead 59AB help
 

Don’t need it.

Re: 1939 Ford flathead 59AB help
 

I have several engines and none of them had the pipe installed. If I remember correctly it is a pipe thread 1/4 " (?). Could use a pipe nipple if needed.

Re: 1939 Ford flathead 59AB help
 

Marko39 yes it is a pipe tap and was going to machine a exact copy of the original ford one.

Re: 1939 Ford flathead 59AB help
 

Thank you for the reply and could you please explain why Ford used the tube and why its not needed. This is going on a Blower flathead motor . I believe the tube was to lubricant the rope seal....thank you

Re: 1939 Ford flathead 59AB help
 

This is not a definitive statement, but my belief is that it is for a drain from the rear bearing, but Ford found out it wasn't necessary so deleted it from the build.

Hopefully someone will confirm or refute.

Mart.

Re: 1939 Ford flathead 59AB help
 

I believe Mart has it correct. The early flatheads (pre 59) that used the slinger for oil control on the rear main had the tube in the main cap for oil return. The tube was no longer used from the 59 blocks on when Ford changed to the rope seal on the rear main. I have a 99 block with the tube hole in the main cap and a 59L block where the rear main does not have the tube hole.

Re: 1939 Ford flathead 59AB help
 

Believe you’ll find that it’s not a pipe thread,can’t tell you the thread butbeen there,,,

Re: 1939 Ford flathead 59AB help
 

I dont have a tube or cap to measure but if someone can throw a caliper or micrometer on the tube or threads that would be awesome. I have a 59A in my roadster but it has the pan on and full of oil.. thank you

Re: 1939 Ford flathead 59AB help
 

As others have said, you don't need the 6328 drain pipe on a post war engine with a rope seal. The purpose of the hole in the rear main cap was to drain oil from the labyrinth type, "slinger", oil seal. My 1937 parts book says the 40-6328 had a check ball at the end and was special equipment, which I took to mean it was not used on every engine.

I checked the rear main cap from my 1937 21 stud engine and the thread is much finer than a 1/4" npt, which has 18 tpi. I think it may be 28 tpi and a 15/32" drill bit fits in the hole, 0.469 in. diameter. I will post a picture of the hole when it finally makes it through to my e-mail.

Re: 1939 Ford flathead 59AB help
 

As others have said, you don't need it. Trust me!
The very early engines 32-34, had no crank case ventilation, and slinger rear main. Crank case windage pressurises the interior of the engine, which looks for a place to escape. Major escape route is through the labyrinth, so a return pipe was fitted, the open end of which is immersed in the oil in the pan. Therefore, that possible/probable/definite oil leak is eliminated [to a degree]
Beginning 1935, and all subsequent production, the crankcase has positive ventilation, therefore there is no pressurisation of crankcase, which precludes the blowing out of oil through the labyrinth, therefore, although the rear main cap was tapped for the fitting of the return pipe, the pipe was not fitted during production.
Certain 'dump truck' applications, whereby a heavy load could lift the front wheels off of the deck, could indeed, tilt the rear of the engine sufficiently to allow oil to leak out through the labyrinth, so in that application, the return pipe was fitted.

Re: 1939 Ford flathead 59AB help
 

Thank you everyone for the reply advice and measurements. I will talk to my buddy and let him know put the pan on . Do we have to plug the hole for the tube or leave it as is?

Re: 1939 Ford flathead 59AB help
 

Just leave it as is. You’re good to go.

Re: 1939 Ford flathead 59AB help
 

if you run an 80# pump with rear sump pan you have to remove it anyway