The Ford Barn

Stage1gs · 09-10-2023, 07:23 PM

Hello.. I had an oil leak on the front of my Model A engine oil pan that resulted from my crank pulley coming loose last year. It tore up the inside of the front pan where the seal goes, and I finally decided to change the pan. So I got a pan from a friend who rebuilds model an engines for a living, cleaned it up, straightened the flanges and put it on. The oil leak at the front stopped but now it’s leaking pretty bad in the back.

My old pan didn’t leak in the back, so it got me thinking. I am using the same brand of oil pan gasket, same engine block, same rear main cap, same weight oil, same snap in tray, and same oil pan bolts, so the difference seems like it’s related to the replacement oil pan.

I have a Model B engine in my garage with a Model A oil pan on it. I thought the rear cap on a B engine was bigger because the journal was bigger, and the oil pan gasket sets do have 2 different seals. So when someone puts a A oil pan on a B, do they just grind out some metal on the back of the pan to accommodate the bigger main cap?

That’s what it is starting to feel like to me.

Stage1gs · 09-10-2023, 07:30 PM

A bit more info.. starting with a clean oil pan, in 10 minutes at idle I have a stream of oil coming from the rear of the oil pan all the way to the center of the oil pan, and then it drips to the floor….

harryc · 09-10-2023, 07:52 PM

get a model b pan---in my 60+ years of fooling around with model A's I have never run across an A pan on a B

Stage1gs · 09-10-2023, 08:47 PM

Now you have

Bob C · 09-10-2023, 09:01 PM

If that's an A pan someone did a very good job of putting the dimples in the side of the pan. Could be a GAZ pan, I have one like that.

Ray in La Mesa · 09-10-2023, 09:03 PM

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I put an "A" pan on a "B" engine, the only difference is the larger rear main cap. I had to enlarge the semicircle to fit the cork gasket on the main cap. It's a little tricky but it came out fine, you have to figure how deep to to make the pan lip press into the cork. Also I used the stock rod nuts which hit the pan sides so just did little metal bumping to the area affected (this was 30 years ago before I knew about smaller rod nuts).

Stage1gs · 09-10-2023, 09:30 PM

So if you put that modified pan on a A engine, would you expect it to leak out the rear of the oil pan?

J Franklin · 09-10-2023, 09:48 PM

Quote:

Originally Posted by Stage1gs

So if you put that modified pan on a A engine, would you expect it to leak out the rear of the oil pan?

For sure!

Ray in La Mesa · 09-10-2023, 09:49 PM

Most definetly, there would be a 1/2" gap between the main cap & the pan! You would need another UNMODIFIED A pan.

harryc · 09-10-2023, 10:03 PM

I believe the oil tray for the rod dippers sits lower in a model B Pan if i am recalling correctly----not positive

Jim Brierley · 09-11-2023, 11:40 AM

The A pan can be used on a B engine by carefully enlarging the rear to fit the B rear main cap. Use ARP 12 point nuts on the rods in order to have clearance between the rods and the side of the pan, otherwise you will have to dimple the A pan so it looks like the sides of the B pan. These nuts do not take cotter pins, they are not needed anyway.

09-10-2023, 07:23 PM	#1
Stage1gs Member Join Date: Nov 2014 Location: Grant, FL Posts: 37	Model A Oil Pan on Model B engine Hello.. I had an oil leak on the front of my Model A engine oil pan that resulted from my crank pulley coming loose last year. It tore up the inside of the front pan where the seal goes, and I finally decided to change the pan. So I got a pan from a friend who rebuilds model an engines for a living, cleaned it up, straightened the flanges and put it on. The oil leak at the front stopped but now it’s leaking pretty bad in the back. My old pan didn’t leak in the back, so it got me thinking. I am using the same brand of oil pan gasket, same engine block, same rear main cap, same weight oil, same snap in tray, and same oil pan bolts, so the difference seems like it’s related to the replacement oil pan. I have a Model B engine in my garage with a Model A oil pan on it. I thought the rear cap on a B engine was bigger because the journal was bigger, and the oil pan gasket sets do have 2 different seals. So when someone puts a A oil pan on a B, do they just grind out some metal on the back of the pan to accommodate the bigger main cap? That’s what it is starting to feel like to me.

09-10-2023, 07:30 PM	#2
Stage1gs Member Join Date: Nov 2014 Location: Grant, FL Posts: 37	Re: Model A Oil Pan on Model B engine A bit more info.. starting with a clean oil pan, in 10 minutes at idle I have a stream of oil coming from the rear of the oil pan all the way to the center of the oil pan, and then it drips to the floor….

09-10-2023, 07:52 PM	#3
harryc Senior Member Join Date: Sep 2012 Location: CA Posts: 206	Re: Model A Oil Pan on Model B engine get a model b pan---in my 60+ years of fooling around with model A's I have never run across an A pan on a B

09-10-2023, 09:01 PM	#5
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 8,754	Re: Model A Oil Pan on Model B engine If that's an A pan someone did a very good job of putting the dimples in the side of the pan. Could be a GAZ pan, I have one like that.

09-10-2023, 09:03 PM	#6
Ray in La Mesa Senior Member Join Date: May 2010 Location: La Mesa Ca Posts: 1,166	Re: Model A Oil Pan on Model B engine Sponsored Links (Register now to hide all advertisements) I put an "A" pan on a "B" engine, the only difference is the larger rear main cap. I had to enlarge the semicircle to fit the cork gasket on the main cap. It's a little tricky but it came out fine, you have to figure how deep to to make the pan lip press into the cork. Also I used the stock rod nuts which hit the pan sides so just did little metal bumping to the area affected (this was 30 years ago before I knew about smaller rod nuts).

09-10-2023, 09:30 PM	#7
Stage1gs Member Join Date: Nov 2014 Location: Grant, FL Posts: 37	Re: Model A Oil Pan on Model B engine So if you put that modified pan on a A engine, would you expect it to leak out the rear of the oil pan?

09-10-2023, 09:49 PM	#9
Ray in La Mesa Senior Member Join Date: May 2010 Location: La Mesa Ca Posts: 1,166	Re: Model A Oil Pan on Model B engine Most definetly, there would be a 1/2" gap between the main cap & the pan! You would need another UNMODIFIED A pan.

09-10-2023, 10:03 PM	#10
harryc Senior Member Join Date: Sep 2012 Location: CA Posts: 206	Re: Model A Oil Pan on Model B engine I believe the oil tray for the rod dippers sits lower in a model B Pan if i am recalling correctly----not positive Last edited by harryc; 09-10-2023 at 10:26 PM.

09-11-2023, 11:40 AM	#11
Jim Brierley Senior Member Join Date: Jun 2010 Location: Temecula, CA Posts: 4,089	Re: Model A Oil Pan on Model B engine The A pan can be used on a B engine by carefully enlarging the rear to fit the B rear main cap. Use ARP 12 point nuts on the rods in order to have clearance between the rods and the side of the pan, otherwise you will have to dimple the A pan so it looks like the sides of the B pan. These nuts do not take cotter pins, they are not needed anyway.