Problem withnew babbited rods

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2014: Problem withnew babbited rods
Top of pagePrevious messageNext messageBottom of page Link to this message  By mike mclean on Sunday, January 12, 2014 - 01:35 pm:

when at Hershey I bought some rabbited rod started to rebuild the motor bored 20 over new alum pistons pulled the rods out to find the Babbitt between the rod and the cap has not been cut what do I have do to cut this apart can I just cut with a hack saw then file it down or use a belt sander to get them down to the right size


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Sunday, January 12, 2014 - 02:11 pm:

What you are saying is; you can't take the cap off the rod? If that is the case, do they even have shims? If not, then I would not use them. Why start off with a fresh motor and have no way to take up wear besides filing the cap even more.

Or are the caps and rods pored but not finished?

When the caps "DO" need to be filed or sanded down for wear while in service you would want to use the top of something like a cast iron table saw and do a few strokes one way turn and do the same number again, trial fit.

If you do use them you will need to cut the oil well in the cap and rod.


Top of pagePrevious messageNext messageBottom of page Link to this message  By mike mclean on Sunday, January 12, 2014 - 02:42 pm:

I think the shims are there ,there is a different colour between the babbitts just don't want to break something do I just need to take the bolts out and knock it apart and use new shims


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Sunday, January 12, 2014 - 04:15 pm:

Have you tried taking the cap off or are you in the looking stage? If there are shims in place why would you need new shims? The shims are laminated in .002 to .003 layers and are peeled off to set your clearances.

I would be real suspicious of rods of unknown origin as to what kind of babbett was used and fixture they were pored on and how esp if you do have to cut them apart to use.

Seems to me the process is pore the babbett, then install the shims and finish to size.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Menzies on Sunday, January 12, 2014 - 05:31 pm:

I would file the rod caps with a chain saw file where they come together. Finished caps and rods are slightly tapered there any ways for the oil to splash in. I have an article from 1916 American Machinist Magazine about pouring Babbitt bearings and a .002 brass shim is inserted between the cap and rod before poring. I am a proponent of the oil scoops.


Top of pagePrevious messageNext messageBottom of page Link to this message  By mike mclean on Sunday, January 12, 2014 - 05:34 pm:

that was what I was trying to do take the cap off so I went back got the bolts out closer look show a little over pour had to cut the edge a bit a little tapping and it came apart the shims are there all looks good just didn't want to break some thing thanks mike


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Sunday, January 12, 2014 - 06:08 pm:

Fantastic! Thanks for reporting back.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Sunday, January 12, 2014 - 06:44 pm:

Do you know whether the babbit has been bored to the size of your crankshaft? If the babbit is standard size and the crank has been turned, the rod bearings will not fit properly. Even if you can remove shims to get them tight, they will then be eliptical and not make good contact all around the crankshaft. They will need to be scraped to get them to fit, and then you might still need to remove more shims or file the caps. It is easy to measure the bore with the proper tool. Do that first before you waste your time going any farther. The bearing and the crankshaft should be the same size only .0015 clearance. If they are, then you can proceed with separating the caps and etc. The outside edges of the bearing should be cut to fit the curve in the crankshaft otherwise the bearing will be tight at the outside edges, but loose in the middle.
Norm


Posting is currently disabled in this topic. Contact your discussion moderator for more information.
Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration