The Ford Barn

Smitty · 09-26-2019, 04:56 AM

In pouring main bearings I am getting some "pock mark" surface texture. This usually cleans up during line boring. Occasionally I will get a deeper crater...
I am using #2 Babbitt and pouring @950 deg. into a block heated with a propane grass burner torch bringing the block to about 400 deg. Using a Wilson pouring fixture and Mold-Pac as a damming material.

Any thoughts, is this normal or should I be looking at something to be corrected?

Thanks, Steve

BRENT in 10-uh-C · 09-26-2019, 06:43 AM

Sounds like trapped air. I am assuming you are speaking of the casting in the block? While not ideal, if after peening it cleans up, then I would not worry.

Joe K · 09-26-2019, 08:45 AM

I have rebabbited a few older machines in my steam and gas engine interests. Usually to the method given by Fine Woodworking Magazine (January-Feb 1983 article by Bob Johnson)

Bob was a restorer for the Smithsonian, did a large portion of the machines of the "1976 Centennial of a Centennial" exhibition in the History & Technology Building of that era and later went into business for himself continuing the tradition of rebuilding antique machinery. He is now passed IIRC.

His recommendation was 80% bedding with Babbitt scrapers and bluing. If you get to that point you pretty much have it covered.

Line boring/hone/bedding should be considerably better than that. Like a single or two imperfections are probably fine. You can call them "oil pockets."

Joe K

Smitty · 09-26-2019, 09:35 AM

Thanks, I poured the block main again this morning and all looks fine. Will definitely clean-up in the line bore. Pouring Babbitt for me at least is kind of a Zen thing... Must be well rested and in the good frame of mind. Sort of like my Model A notices cooler weather before I do. Wants a little richer mixture when starting.
Steve

rotorwrench · 09-26-2019, 10:26 AM

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All I know is that the babbitt has to be the right temperature and poured quickly from both sides. KR Wilson claimed that the pour could be done with a cold block but they also stressed using the Ford type babbitt even in their 1926 catalog (model T era) and that it be the correct temperature. It has to be able to get the gases out of the mold as it's poured.

09-26-2019, 04:56 AM	#1
Smitty Senior Member Join Date: May 2010 Location: Boston North Shore Posts: 752	Main Bearing Poured Surface In pouring main bearings I am getting some "pock mark" surface texture. This usually cleans up during line boring. Occasionally I will get a deeper crater... I am using #2 Babbitt and pouring @950 deg. into a block heated with a propane grass burner torch bringing the block to about 400 deg. Using a Wilson pouring fixture and Mold-Pac as a damming material. Any thoughts, is this normal or should I be looking at something to be corrected? Thanks, Steve

09-26-2019, 08:45 AM	#3
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,188	Re: Main Bearing Poured Surface I have rebabbited a few older machines in my steam and gas engine interests. Usually to the method given by Fine Woodworking Magazine (January-Feb 1983 article by Bob Johnson) Bob was a restorer for the Smithsonian, did a large portion of the machines of the "1976 Centennial of a Centennial" exhibition in the History & Technology Building of that era and later went into business for himself continuing the tradition of rebuilding antique machinery. He is now passed IIRC. His recommendation was 80% bedding with Babbitt scrapers and bluing. If you get to that point you pretty much have it covered. Line boring/hone/bedding should be considerably better than that. Like a single or two imperfections are probably fine. You can call them "oil pockets." Joe K __________________ Shudda kept the horse.

09-26-2019, 09:35 AM	#4
Smitty Senior Member Join Date: May 2010 Location: Boston North Shore Posts: 752	Re: Main Bearing Poured Surface Thanks, I poured the block main again this morning and all looks fine. Will definitely clean-up in the line bore. Pouring Babbitt for me at least is kind of a Zen thing... Must be well rested and in the good frame of mind. Sort of like my Model A notices cooler weather before I do. Wants a little richer mixture when starting. Steve

09-26-2019, 10:26 AM	#5
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,426	Re: Main Bearing Poured Surface Sponsored Links (Register now to hide all advertisements) All I know is that the babbitt has to be the right temperature and poured quickly from both sides. KR Wilson claimed that the pour could be done with a cold block but they also stressed using the Ford type babbitt even in their 1926 catalog (model T era) and that it be the correct temperature. It has to be able to get the gases out of the mold as it's poured.

09-26-2019, 06:43 AM	#2
BRENT in 10-uh-C Senior Member Join Date: May 2010 Location: Eastern Tennessee Posts: 11,507	Re: Main Bearing Poured Surface Sounds like trapped air. I am assuming you are speaking of the casting in the block? While not ideal, if after peening it cleans up, then I would not worry. __________________ . BRENT in 10-uh-C . www.model-a-ford.com ...(...Finally Updated!! ) .