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Mark's 37 · 12-06-2015, 06:17 PM

Bored&Stroked

Thanks for making the effort to explain fitting these floating bearings. I have found information is a little scarce and varied as to what is the best way to set them up. I decided to make this part of my build a continuous thread here while I stumble through it in order to get some good advice as well as possibly provide a source of info for others. When I come to a problem like setting up floater bearings and struggle to get it right I just have to butt heads with it, make the mistakes, and push on until it works. I could find a shop that could do all this for a price but being a 78 year old engine I would rather do it myself and know it was done right. Your Youtube video was one of the first things I found and have watched it many times while doing this.

I started by attempting to mic the outside OD’s of the bearing halves at the ends and compare them to the rod bore diameter. Then put the two bearing halves together and measuring the diameter across 90 degrees from where they join together. Then using a plastic soft head hammer to narrow the ends or tapping the tops of the bearings leaving an acceptable bore to bearing clearance Again using the outside micrometer I could not get the two measurements the same. Always egg shaped in the bore one way or the other. I have also tried measuring the ID of the bearing with the dial bore gauge but not really helpful. I found this video on Youtube helpful in rod bore measuring.

https://www.youtube.com/watch?v=SuO6qvtQR_8

The micrometers and dial bore gauge I have are from Summit and clearly not the industry standard for sure. After many hours futzing with it I realized it was getting me nowhere. Measurements are too subjective and I am not a machinist with a seasoned “feel” for doing them. Having several sets of rod bearings doesn’t fit my wallet though but I have a second set of Genuine Ford Parts bearings coming next week. That will help.

As of last night, I have managed to get one bearing near fitted. Using the hammer to adjust the widths and polishing with 800 grit paper and lacquer thinner on the bearing surfaces and the rod bore I am pretty close. I set the bearing half in a vice lined with pieces of particle board tight enough to hold the bearing sides stationary but hopefully not enough to crush them. Cut some 12” strips of 800 3M wet/dry sandpaper the width of the bearing and wrapping the strips around the bearing sanding with a push/pull motion. I also went over the rod bore surfaces with 400 grit to clean them up then polished with the 800 grit. With it installed and torqued on the rod journal the rod moves freely over the bearing. It is still a little tight when I grasp the bearing and move it on the crank though so more polishing to do.

A couple questions.

Is placing the bearing half with ends down on sandpaper (800grit) on a flat surface (flywheel) to polish and remove some material to gain clearance a good idea?

How do you arrive at the bearing clearance measurement? I was considering putting plastigage on both sides of the bearing in several places and torquing them down but figured it would be more confusing than reliable.

12-06-2015, 06:17 PM	#33
Mark's 37 Senior Member Join Date: Jul 2015 Location: Aptos, Ca Posts: 355	Re: Reconditioned 37 rods Bored&Stroked Thanks for making the effort to explain fitting these floating bearings. I have found information is a little scarce and varied as to what is the best way to set them up. I decided to make this part of my build a continuous thread here while I stumble through it in order to get some good advice as well as possibly provide a source of info for others. When I come to a problem like setting up floater bearings and struggle to get it right I just have to butt heads with it, make the mistakes, and push on until it works. I could find a shop that could do all this for a price but being a 78 year old engine I would rather do it myself and know it was done right. Your Youtube video was one of the first things I found and have watched it many times while doing this. I started by attempting to mic the outside OD’s of the bearing halves at the ends and compare them to the rod bore diameter. Then put the two bearing halves together and measuring the diameter across 90 degrees from where they join together. Then using a plastic soft head hammer to narrow the ends or tapping the tops of the bearings leaving an acceptable bore to bearing clearance Again using the outside micrometer I could not get the two measurements the same. Always egg shaped in the bore one way or the other. I have also tried measuring the ID of the bearing with the dial bore gauge but not really helpful. I found this video on Youtube helpful in rod bore measuring. https://www.youtube.com/watch?v=SuO6qvtQR_8 The micrometers and dial bore gauge I have are from Summit and clearly not the industry standard for sure. After many hours futzing with it I realized it was getting me nowhere. Measurements are too subjective and I am not a machinist with a seasoned “feel” for doing them. Having several sets of rod bearings doesn’t fit my wallet though but I have a second set of Genuine Ford Parts bearings coming next week. That will help. As of last night, I have managed to get one bearing near fitted. Using the hammer to adjust the widths and polishing with 800 grit paper and lacquer thinner on the bearing surfaces and the rod bore I am pretty close. I set the bearing half in a vice lined with pieces of particle board tight enough to hold the bearing sides stationary but hopefully not enough to crush them. Cut some 12” strips of 800 3M wet/dry sandpaper the width of the bearing and wrapping the strips around the bearing sanding with a push/pull motion. I also went over the rod bore surfaces with 400 grit to clean them up then polished with the 800 grit. With it installed and torqued on the rod journal the rod moves freely over the bearing. It is still a little tight when I grasp the bearing and move it on the crank though so more polishing to do. A couple questions. Is placing the bearing half with ends down on sandpaper (800grit) on a flat surface (flywheel) to polish and remove some material to gain clearance a good idea? How do you arrive at the bearing clearance measurement? I was considering putting plastigage on both sides of the bearing in several places and torquing them down but figured it would be more confusing than reliable. Last edited by Mark's 37; 12-06-2015 at 06:40 PM.