The Ford Barn

dubnutty · 06-28-2015, 05:32 PM

Can someone explain about babbitts on a 1929 engine for me? I took off the rod caps to move the pistons up in the bore and there seems to be material around the rod studs. As I removed the caps small paper thin material was coming loose. If I reassemble these caps, this tolerance will change without this "shim". Won't it? It kind of just fell out on some of the caps. I posted a picture along with this post. I don't know what to do when I reassemble these rods. I'm just trying to unstick this motor and start it up but it may now need an overhaul.

Tom Wesenberg · 06-28-2015, 08:42 PM

You need to keep each of the shims in the same location they came from. Also make sure the rod caps stay in the same position they were, and the open end of the dipper scoop must face the cam shaft. Also by the picture the oil looks very dirty, but I'm sure a thorough cleaning was in the works anyway.

Mike V. Florida · 06-28-2015, 11:26 PM

Those shims are a necessity for the future compensation of bearing wear.

PC/SR · 06-29-2015, 10:56 AM

The shims are used to set the clearance between the rods and the crankshaft. As noted they should go back in the same sequence as when removed otherwise as you note the "tolerance" will change. Since you have it down anyway, check the clearances when you reassemble. Clearance should be close to .0015. Some use Plastigage for measuring, others use the "tinfoil" method. There are numerous posts in the Search section on how to make the installation and adjustment.

dubnutty · 06-29-2015, 03:11 PM

Thanks all! Wealth of info here!

WestCoast · 06-30-2015, 11:44 PM

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I think it would be a good idea to plasta gage the rods while you have them off and re shim if necessary

06-28-2015, 08:42 PM	#2
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Babbitts You need to keep each of the shims in the same location they came from. Also make sure the rod caps stay in the same position they were, and the open end of the dipper scoop must face the cam shaft. Also by the picture the oil looks very dirty, but I'm sure a thorough cleaning was in the works anyway.

06-28-2015, 11:26 PM	#3
Mike V. Florida Senior Member Join Date: May 2010 Location: South Florida Posts: 14,054	Re: Babbitts Those shims are a necessity for the future compensation of bearing wear. __________________ What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II

06-29-2015, 10:56 AM	#4
PC/SR Senior Member Join Date: May 2010 Location: Santa Rosa, CA Posts: 1,279	Re: Babbitts The shims are used to set the clearance between the rods and the crankshaft. As noted they should go back in the same sequence as when removed otherwise as you note the "tolerance" will change. Since you have it down anyway, check the clearances when you reassemble. Clearance should be close to .0015. Some use Plastigage for measuring, others use the "tinfoil" method. There are numerous posts in the Search section on how to make the installation and adjustment.

06-29-2015, 03:11 PM	#5
dubnutty Member Join Date: Mar 2015 Location: Las Vegas, NV Posts: 56	Re: Babbitts Thanks all! Wealth of info here! __________________ I'd go to the far ends of the earth for a GOOD beer.

06-30-2015, 11:44 PM	#6
WestCoast Senior Member Join Date: Sep 2014 Location: oroville calif Posts: 893	Re: Babbitts Sponsored Links (Register now to hide all advertisements) I think it would be a good idea to plasta gage the rods while you have them off and re shim if necessary