The Ford Barn

Jeffers · 10-30-2015, 06:52 PM

Can' t decide if going to insert mains in Model A is a good thing or not what is the general consensus?

DJ S · 10-30-2015, 07:48 PM

Babbitt bearings are far more forgiving than inserts. However, inserts are far more beneficial as you can easily replace a bearing. It's all up to personal preference.

Kevin in NJ · 10-30-2015, 07:59 PM

No concensus needed. Personal choice after education.

My comments are as follows.

Either method works fine and lasts a long time, but it depends on having a well qualified experienced installer.
Lots of pitfalls. Some guys are just good at doing machine work.

If properly installed either will give you tens of thousands of miles of life with assumptions. When you have the job the the crank and all the moving parts are very very carefully machined and balanced to tight tolerances.

The primary difference in the bearins is the fail mode.
Babbitt will generally fail gently with warning. You can go many miles limping in some cases.

Inserts will fail quickly and likely damage the crank and require more work to save the block.

BUT if everything is properly machined that should not be a problem.

For various reasons, I have the though that going with the set of new rods with inserts and babbitt mains might be a good idea. This is based in what I know about how babbitt rods are being done in some cases.

In any event, if you want to make sure it is done right it is not fast or cheap.

Ron W · 10-30-2015, 08:21 PM

I have all inserts. When I did the machine work I made sure I provided channels for the oil To get where it needs to be. Without pressure that is critical! If you go with inserts have it done by someone well versed in the process. Ron Kelly comes to mind but there are others. Good luck! Ron W

Jim Brierley · 10-31-2015, 10:48 AM

Sponsored Links (Register now to hide all advertisements)

I agree with Kevin in NJ, both are good so it is personal preference. Babbitt works exceptionally well in mains (as compared to rods) and eliminates all the work of fitting a thrust bearing.

10-30-2015, 06:52 PM	#1
Jeffers Junior Member Join Date: Oct 2015 Location: Alexander NY Posts: 1	model A main bearing Can' t decide if going to insert mains in Model A is a good thing or not what is the general consensus?

10-30-2015, 07:48 PM	#2
DJ S Senior Member Join Date: Aug 2014 Location: Southwick, MA Posts: 590	Re: model A main bearing Babbitt bearings are far more forgiving than inserts. However, inserts are far more beneficial as you can easily replace a bearing. It's all up to personal preference.

10-30-2015, 07:59 PM	#3
Kevin in NJ Senior Member Join Date: May 2010 Location: South East NJ Posts: 3,398	Re: model A main bearing No concensus needed. Personal choice after education. My comments are as follows. Either method works fine and lasts a long time, but it depends on having a well qualified experienced installer. Lots of pitfalls. Some guys are just good at doing machine work. If properly installed either will give you tens of thousands of miles of life with assumptions. When you have the job the the crank and all the moving parts are very very carefully machined and balanced to tight tolerances. The primary difference in the bearins is the fail mode. Babbitt will generally fail gently with warning. You can go many miles limping in some cases. Inserts will fail quickly and likely damage the crank and require more work to save the block. BUT if everything is properly machined that should not be a problem. For various reasons, I have the though that going with the set of new rods with inserts and babbitt mains might be a good idea. This is based in what I know about how babbitt rods are being done in some cases. In any event, if you want to make sure it is done right it is not fast or cheap.

10-30-2015, 08:21 PM	#4
Ron W Senior Member Join Date: Jan 2011 Location: Central Me. Posts: 260	Re: model A main bearing I have all inserts. When I did the machine work I made sure I provided channels for the oil To get where it needs to be. Without pressure that is critical! If you go with inserts have it done by someone well versed in the process. Ron Kelly comes to mind but there are others. Good luck! Ron W

10-31-2015, 10:48 AM	#5
Jim Brierley Senior Member Join Date: Jun 2010 Location: Temecula, CA Posts: 4,087	Re: model A main bearing Sponsored Links (Register now to hide all advertisements) I agree with Kevin in NJ, both are good so it is personal preference. Babbitt works exceptionally well in mains (as compared to rods) and eliminates all the work of fitting a thrust bearing.