152 Rod Bearing Size Determination Help

M

Motoracer34

New member
I'm trying to find out which rod bearings I need. The crank had to have some rust galling ground out and the owner didn't bother to ask any questions as to how much was removed and when I tried to install the bearings he had (clevite cb-633) they barely squeezed the plastigages.
I don't know where to find any of the specs to determine the oversize bearing needed. The crank was ground to 2.359" if that is anything someone might be able to use.

Thanks for the help, chris
 
The stock rod journal is 2.375 in round numbers so you are .015 under. Most crank grinders will stamp the under size on the crank some where. Usually r-.015 m-.010 have a good close look at the crank for any markings.

For reference the mains are 2.750 standard. Going on memory on that diameter so have a measure and see.
 
Thanks for the specs. My only question now is will a 10 under bearing work with that grind? It May sound silly but at this point I'm not going to assume anything. I took the project on after 2 other people did work so I am trying to be super careful at every turn.
Thanks again!
 
motoracer34 said:
thanks for the specs. My only question now is will a 10 under bearing work with that grind? It May sound silly but at this point I'm not going to assume anything. I took the project on after 2 other people did work so I am trying to be super careful at every turn.
Thanks again!
Click to expand...

Before I could answer that you would need to accuratly measure all 4 rod journals at multiple places to 4 decimal places (2.3xxx).
 
Here is the data for the shaft diameter and the bearing housing bore. These are requirements so if either are out they need to be resized.
 

Attachments

  • IH bearing data.pdf
    28.5 KB · Views: 594
Robert,
thank you very much for that pdf. That is exactly what I need to show both the owner and the machine shop so I can get this done right the 'second' time.:thumbsup: you guys are great and appreciated.
So many times now days you just get some troll who doesn't have any clue what they are talking about but until we can validate things we waste hours and hours of time researching to find answers.

Chris
 
You must log in or register to reply here.
Back
Top