Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 01-07-2018, 06:50 PM   #1
Chuck Sea/Tac
Senior Member
 
Chuck Sea/Tac's Avatar
 
Join Date: May 2010
Location: Between Seattle & Tacoma
Posts: 1,526
Default Rear main oil return tube

I broke one off , flipping the engine around while installing pistons. It was tacked in place. I was able to get the broken threaded piece out easily. I went to see if I had some 5/16” ones on old caps. Found two with a ball check valve. Anyone know the “theory “ behind this??
Attached Images
File Type: jpg 38498F05-4190-4BB9-8B58-9FA99E061DFC.jpg (50.7 KB, 77 views)
File Type: jpg 889F4E2A-A597-4C02-8960-03A4DF0B05DE.jpg (91.4 KB, 82 views)
Chuck Sea/Tac is offline   Reply With Quote
Old 01-07-2018, 06:53 PM   #2
George Miller
Senior Member
 
George Miller's Avatar
 
Join Date: May 2010
Location: NC
Posts: 2,889
Default Re: Rear main oil return tube

They were for grain trucks. They use to pick the front of the trucks up in the air, to dump the grain. The ball kept the oil from running out of the engine.
George Miller is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 01-07-2018, 07:31 PM   #3
Kohnke Rebabbitting
Senior Member
 
Join Date: May 2010
Location: 60615,330th Ave.,Clare, Iowa, 50524
Posts: 1,268
Default Re: Rear main oil return tube

Do not use 5/16 ones. If that is the size, bore to accept the newer 3/8's.

Look for other posts on the barn on how to do the complete job.

I have to leave right now.

Herm.
Kohnke Rebabbitting is offline   Reply With Quote
Old 01-07-2018, 11:06 PM   #4
Chuck Sea/Tac
Senior Member
 
Chuck Sea/Tac's Avatar
 
Join Date: May 2010
Location: Between Seattle & Tacoma
Posts: 1,526
Default Re: Rear main oil return tube

Page 306 in the service bulletins. Thanks
Chuck Sea/Tac is offline   Reply With Quote
Old 01-09-2018, 10:43 AM   #5
Dave in MN
Senior Member
 
Dave in MN's Avatar
 
Join Date: May 2010
Location: Jordan, MN
Posts: 1,052
Default Re: Rear main oil return tube

Quote:
Originally Posted by Kohnke Rebabbitting View Post
Do not use 5/16 ones. If that is the size, bore to accept the newer 3/8's.

Look for other posts on the barn on how to do the complete job.

I have to leave right now.

Herm.
I agree with Herm: 5/16" is limited to the amount of oil flow it can handle. They have caused rear main leaks for me. I change all rear caps over to 3/8".
Good Day!

www.durableperformance.net
Dave in MN is offline   Reply With Quote
Old 01-09-2018, 12:11 PM   #6
George Miller
Senior Member
 
George Miller's Avatar
 
Join Date: May 2010
Location: NC
Posts: 2,889
Default Re: Rear main oil return tube

Quote:
Originally Posted by Dave in MN View Post
I agree with Herm: 5/16" is limited to the amount of oil flow it can handle. They have caused rear main leaks for me. I change all rear caps over to 3/8".
Good Day!

www.durableperformance.net

I also change them to 3/8 Ford changed them to 3/8 because 5/16 is to small.
George Miller is offline   Reply With Quote
Old 01-09-2018, 03:48 PM   #7
Synchro909
Senior Member
 
Join Date: Jun 2014
Location: Melbourne, Australia
Posts: 3,255
Default Re: Rear main oil return tube

3/8" gives 20% more flow than 5/16", FWIW.
__________________
The only substitute for good manners is fast reflexes.
Synchro909 is offline   Reply With Quote
Old 01-09-2018, 04:02 PM   #8
hardtimes
Senior Member
 
hardtimes's Avatar
 
Join Date: May 2010
Location: South California
Posts: 5,739
Default Re: Rear main oil return tube

Quote:
Originally Posted by George Miller View Post
I also change them to 3/8 Ford changed them to 3/8 because 5/16 is to small.
Hey George,
I realize that the tube thread (3/8) is peculiar. Other than not having right die, is there anything that you can think of , why a guy cannot make one ?
I just got a B block without the drain tube....and as things go last few years, can not locate much when needed/wanted in stuff pile !
hardtimes is offline   Reply With Quote
Old 01-09-2018, 07:56 PM   #9
Tom Wesenberg
Senior Member
 
Tom Wesenberg's Avatar
 
Join Date: May 2010
Location: Mpls, MN
Posts: 26,739
Default Re: Rear main oil return tube

Quote:
Originally Posted by Synchro909 View Post
3/8" gives 20% more flow than 5/16", FWIW.
Actually about 50% more flow, since you square the radius and multiply by pi to find the area.
Tom Wesenberg is offline   Reply With Quote
Old 01-09-2018, 08:15 PM   #10
1955cj5
Senior Member
 
1955cj5's Avatar
 
Join Date: Apr 2015
Location: Boise, Idaho
Posts: 1,361
Default Re: Rear main oil return tube

Quote:
Originally Posted by George Miller View Post
They were for grain trucks. They use to pick the front of the trucks up in the air, to dump the grain. The ball kept the oil from running out of the engine.
That is interesting.....I'd like to see a picture!


.
__________________
Early '29 CCPU that had a 4-speed, but not any more.......in the family since '62
1955cj5 is offline   Reply With Quote
Old 01-09-2018, 08:28 PM   #11
Tom Wesenberg
Senior Member
 
Tom Wesenberg's Avatar
 
Join Date: May 2010
Location: Mpls, MN
Posts: 26,739
Default Re: Rear main oil return tube

Quote:
Originally Posted by 1955cj5 View Post
That is interesting.....I'd like to see a picture!


.
They still dump grain that way for the trucks without a lift.
Shorpy has lots of old pictures, or Google might turn up a picture.
Google "tipping truck to dump grain"
Tom Wesenberg is offline   Reply With Quote
Old 01-09-2018, 09:18 PM   #12
George Miller
Senior Member
 
George Miller's Avatar
 
Join Date: May 2010
Location: NC
Posts: 2,889
Default Re: Rear main oil return tube

Quote:
Originally Posted by hardtimes View Post
Hey George,
I realize that the tube thread (3/8) is peculiar. Other than not having right die, is there anything that you can think of , why a guy cannot make one ?
I just got a B block without the drain tube....and as things go last few years, can not locate much when needed/wanted in stuff pile !
You might use a pipe thread. It will work fine.
George Miller is offline   Reply With Quote
Old 01-09-2018, 10:11 PM   #13
hardtimes
Senior Member
 
hardtimes's Avatar
 
Join Date: May 2010
Location: South California
Posts: 5,739
Default Re: Rear main oil return tube

Quote:
Originally Posted by George Miller View Post
You might use a pipe thread. It will work fine.
Ok, thanks !
Hadn't thought of that .
I guess copper pipe would work, instead of steel as used by Ford.
hardtimes is offline   Reply With Quote
Old 01-09-2018, 11:31 PM   #14
Synchro909
Senior Member
 
Join Date: Jun 2014
Location: Melbourne, Australia
Posts: 3,255
Default Re: Rear main oil return tube

...
__________________
The only substitute for good manners is fast reflexes.
Synchro909 is offline   Reply With Quote
Old 01-10-2018, 12:39 PM   #15
Purdy Swoft
Senior Member
 
Purdy Swoft's Avatar
 
Join Date: May 2010
Location: Alabama
Posts: 6,436
Default Re: Rear main oil return tube

Here is what I do ...There is more to it than 3/8 . Its the number of threads per inch if you need to fit a replacement drain tube to a 3/8 hole . I use a 3/8 by 32 threads per inch tap . This works with the drain tube threads that most model A parts venders handle. This is probably an uncommon tap . I got mine from Kodiak cutting tools www.amazon.com or www.kodiakcuttingtools.com . Brattons lists the drain tubes on page 44 and yes I have performed this proceduer many times .
Purdy Swoft is offline   Reply With Quote
Old 01-10-2018, 02:19 PM   #16
Dave in MN
Senior Member
 
Dave in MN's Avatar
 
Join Date: May 2010
Location: Jordan, MN
Posts: 1,052
Default Re: Rear main oil return tube

Purdy is probably correct about the 3/8 by 32 but I have found George Miller's suggestion works for me.

I use a 1/8" pipe thread tap and it always works. I spot weld the 3/8"steel pipe to the cap with stainless wire and find it holds well. I also drill out the oil passage in the cap to 3/8" when doing this conversion. Be careful, go slow, when the tip of the drill bit nears the back of the cap as the bit can bind in the grooves.

The tapped hole is not 90 degrees to the parting line of the cap. I built a jig from a cut-off of 10" structural "C" channel to position the cap to achieve the correct angle. If you place a 3/16" spacer under the front edge of cap with the rear of the cap on the bed of your drill press, the angle of the pipe will be correct. I use a 5/16" drill to prepare the cap for the 1/8" pipe thread tap and while the cap is in the jig, I use the drill press to start the tap to achieve alignment.
Photos below:
This jig is used for multiple functions...so ignore the other holes and knotches.

The bottom row of photos shows the procedure to enlarge the oil passage.
Remove galley plug with a punch...Drill passage with a 3/8" bit....continue drilling but don't drill out the back side. The last photo shows where to stop.
Good Day!
Attached Images
File Type: jpg 20180110_174239_resized.jpg (31.5 KB, 87 views)
File Type: jpg 20180110_174330_resized.jpg (45.2 KB, 81 views)
File Type: jpg 20180110_174557_resized.jpg (34.7 KB, 87 views)
File Type: jpg 20180110_174443_resized.jpg (48.2 KB, 73 views)
File Type: jpg 20180110_174321_resized.jpg (46.5 KB, 74 views)
File Type: jpg 20180112_204415_1515811790348_resized-2.jpg (34.2 KB, 39 views)
File Type: jpg 20180112_203937_1515811794255_resized-2.jpg (45.6 KB, 39 views)
File Type: jpg 20180112_204138_1515811793109_resized-2.jpg (50.8 KB, 42 views)
File Type: jpg 20180112_204255_1515811791996_resized-2.jpg (41.0 KB, 41 views)

Last edited by Dave in MN; 01-12-2018 at 10:14 PM. Reason: Add photos
Dave in MN is offline   Reply With Quote
Old 01-10-2018, 03:07 PM   #17
Beater
Senior Member
 
Beater's Avatar
 
Join Date: Aug 2015
Location: Southern Alberta
Posts: 301
Default Re: Rear main oil return tube

very interesting. I have to pull the pan on my speedster as the oil plug is loose and just spins. while its out I think ill drop the rear main and do this upgrade
Beater is offline   Reply With Quote
Old 01-10-2018, 03:16 PM   #18
George Miller
Senior Member
 
George Miller's Avatar
 
Join Date: May 2010
Location: NC
Posts: 2,889
Default Re: Rear main oil return tube

Quote:
Originally Posted by Dave in MN View Post
Purdy is probably correct about the 3/8 by 32 but I have found George Miller's suggestion works for me.

I use a 1/8" pipe thread tap and it always works. I spot weld the 3/8"steel pipe to the cap with stainless wire and find it holds well. I also drill out the oil passage in the cap to 3/8" when doing this conversion. Be careful, go slow, when the tip of the drill bit nears the back of the cap as the bit can bind in the grooves.

The tapped hole is not 90 degrees to the parting line of the cap. I built a jig to position the cap to achieve the correct angle. If you place a 1/8" spacer under the front edge of cap with the rear of the cap on the bed of your drill press, the angle of the pipe will be correct. I have a photo of my jig I will add to the post later if I can find it...or I'll take another photo.
Good Day!

Dave is right on. I also drill the oil passage also very important. You never know what you are going to find in that hole. Plus it fixes the tube from blocking the oil flow through the cap, if it is screwed in to far.
George Miller is offline   Reply With Quote
Old 01-11-2018, 09:51 AM   #19
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Alberta, Canada
Posts: 1,322
Default Re: Rear main oil return tube

Quote:
I guess copper pipe would work, instead of steel as used by Ford.
I'd stay away from copper on this application. It might "work harden" from vibration and then crack and fall off. Why take a chance? Use steel and be done w/it.
__________________
Talk slow, think fast.
katy is offline   Reply With Quote
Old 01-11-2018, 01:18 PM   #20
Kohnke Rebabbitting
Senior Member
 
Join Date: May 2010
Location: 60615,330th Ave.,Clare, Iowa, 50524
Posts: 1,268
Default Re: Rear main oil return tube

Quote:
Originally Posted by Dave in MN View Post
Purdy is probably correct about the 3/8 by 32 but I have found George Miller's suggestion works for me.

I use a 1/8" pipe thread tap and it always works. I spot weld the 3/8"steel pipe to the cap with stainless wire and find it holds well. I also drill out the oil passage in the cap to 3/8" when doing this conversion. Be careful, go slow, when the tip of the drill bit nears the back of the cap as the bit can bind in the grooves.

The tapped hole is not 90 degrees to the parting line of the cap. I built a jig to position the cap to achieve the correct angle. If you place a 3/16" spacer under the front edge of cap with the rear of the cap on the bed of your drill press, the angle of the pipe will be correct. I use a 5/16" drill to prepare the cap for the 1/8" pipe thread tap and while the cap is in the jig, I use the drill press to start the tap to achieve alignment.
Photos below:
This jig is used for multiple functions...so ignore the other holes and knotches.
Good Day!
Good Jig, Dave.

Herm.
Kohnke Rebabbitting is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 07:20 AM.