Need some rod bearing selection help

[Crammysauce!]

I got the CAT forged crank and K-1 rods for an engine build. The machine shop is telling me that the fillet on the outer edges of the rod journals are come too far in for them to use the bearings that they have. Is there a set of chamfered rod bearings that accounts for the fillets? I hate riding my bicycle. Please help me.

 

[turboavery]

The Clevite H series bearings have large chamfers for greater crankshaft fillet clearance, CB1398H. I have not used these with your crank though.

 

[87buickracer]

also federal mogul 3755apa if you can find them.

 

[Crammysauce!]

Thanks for the info.

Is the 3755AP set not the same as the 3755APA set?

 

[blown okie]

if the machine shop is real handy and clever they can chamfer the bearings more themselves, have had to do it on different occasions with absolutley no problems down the road.

 

[jpwalt1987]

I have an Eagle crank and ran into the same problem. Although I would have liked to use a lathe to do the job, My dremel and a whole lot of patience got it done nicely. These are FM race series bearings(7120ch) good luck, jeremy

 

[Crammysauce!]

Yeah, the guy that's doing the build offered to do the chamfering job on the bearings - I just wanted to keep the labor costs down and get something in there that works right out of the box. I ended up ordering a set of the CB1398H Clevite 77 bearings from Summit. Hopefully the chamfer is right for the job. Seems crazy that you can buy a crank that could simply not have any bearings readily available for it.

Is there anyone out there that has had an out of the box set of rod bearings installed on a CAT crank, and had NO fitment issues??

 

[Blown&Injected]

CB-1398 H
and107 M on the Mains

 

[jpwalt1987]

From what dan at DLS told me and i saw for myself you still have to chamfer the rod bearings. jeremy

 

[KWIKR 1]

From DLS off invoice : FM Rod Bearings $49.95

Labor Narrow Rod Bearings - $55.00

 

[Crammysauce!]

CB-1398 H
and107 M on the Mains

So, you have used the CB1398H bearings (without any of these problems) - or did you have to get them worked too? Looks like I'll find out soon anyway, I just want to be prepared for what to expect. Thanks for all the replies, guys. I appreciate the help.

 

[Blown&Injected]

No problem at all

Of course I have only driven the car 2 car lengths!!!!!!

I backed it out of the garage and then pulled it back in.

The machine shop told me that the bearings will work on my crank. When I move the rods back and forth on the crank pin it looks like the rods keep the bearing far off the radius. It also looks like there would be only a tiny section of bearing left if it were cut.

I will post back some pics that look just like the problem being mentioned in the thread.

 

[Blown&Injected]

These were NOT the H bearings I have in now - NOT the one's were are talking about:

http://www.turbobuick.com/forums/showthread.php?t=211189&referrerid=1527
http://www.turbobuick.com/forums/showthread.php?t=209905&referrerid=1527

 

[Crammysauce!]

I just ended up calling Dan at DLS. He's sending me a set of bearings that have the proper chamfer. Thanks for all the input, guys!

 

[Blown&Injected]

Please post some pics of them when you get the chance.

Are they bearings that have been cut or just the right ones straight out of the box?

What did he say about the cb-1398-h?

 

[gnxtc2]

Thanks for the info.

Is the 3755AP set not the same as the 3755APA set?

APA's are 10% wider than the AP's

Billy T.
gnxtc2@aol.com

 

[norbs]

I think the cb-1398H you dont have to cut them for the crank. I did a test fit and they looked fine, on a billet crank.

 

[Crammysauce!]

According to Dan @ DLS, the CB1398H bearing will not work right out of the box. They have to be modified by chamfering the edges (even though they already have a chamfer) to clear the fillet on the CAT cranks. I will take measurements with the MIC and post results.

 

[Blown&Injected]

According to Dan @ DLS, the CB1398H bearing will not work right out of the box. They have to be modified by chamfering the edges (even though they already have a chamfer) to clear the fillet on the CAT cranks. I will take measurements with the MIC and post results.

Oh great. I had the machine shop check out my crank and gave then the bearings that are in the link above and told them that I need bearings that will work that the wide bearings need to be cut - they said the CB1398H will work. They just polished the crank. That should not cut the radius down but it sure looks like it should work.

 

[noahzark]

...so anyone find any rod bearings that work out of the box or is the 1398's with extra work the only ones???