Lentz Rods - Bearing Fitment Issue ?

[ed]

Got my calico/clevite rod bearings yesterday and theres a bit of a problem!

I was advised to use clevite CB1663H bearings, and it appears from the marking on the rods that this bearing part number has been used in them before (you can see the oil stain silhouette in the rod from the bearing inscription) however it appears when you install my bearings, that the upper and lower bearings shells are offset to each other when assembled with the tangs properly engaged. see the pics below to see what im talking about. I have contacted Lentz and Clevite and am awaiting their replies. (My rods are a Lentz rod, 6.0" SBC with 1.888" big end, .904" width)

The problem seems to lie in the location of the tang in the bearing, namely the tang is too far towards the centre of the bearing, which then pushes the bearing around 1-1.5mm off from the centreline of the rod. thus when the two half are then assembled, they dont meet around the centreline of the rod, and instead are offset to each other. do we perhaps have the wrong bearing for this rod? it looks like the rods are clearly marked as cb1663h, is there another variant of this bearing with different tang positions? i anyone aware of any changes or idiosncyracies with clevite bearings that would be relevant?

if something's all FUBAR and getting the correct bearing is a major PITA, is there actually a problem with running the bearings slightly offset as in the pics? obviously youd need to ensure they didnt protrude from the side of the rod thrust face, but aside from that? any difference between that and just running a narrower bearing? what about increasing the size of the notch in the rod and sliding the bearings over? that seems dodgy to me as the bearing isnt then positively located in a side to side fashion, but i thought it worthwhile putting it to the crowd as its the only other idea ive got if we cant figure out why these bearing part numbers arent working?





any advice anyone's able to offer would be greatly appreciated.

cheers
ed

[jeffro ra28]

Yep, bit of a problem

Probably not that helpful at all but on some old school cheap hybrid holden/chev strokers, machining the bearing shells narrower was required and worked without drama's in most cases. I think the issue was with the radius on the crank journal fouling on bearing (havent done any for a while). Looks like you might have a problem there aswell.

Im not sure you'd want to go machining your nice coated bearings down tho. Id be looking for another P/N, surely they arent custom bearings for those rods.

Its pretty dead obvious and sorry for asking but you have checked for any other bearing witness marks from there previous life? Is that P/N silhouette on the rod and cap?

Possibly there is upper and lower shells (usually main bearings tho) with that part number and you have ended up with one side only? On the odd occasion bearing packers do stuff up but its very rare and generally only one shell out of place.

[ed]

from calico:

Ed,

This is not that uncommon. For some customers, we narrow the bearing on the
tang side the amount required to match up these bearings. Most times it for
folks using Lentz rods. Let me know how you want us to proceed.

David Adams
Calico Coatings

[ed]

from an IRL engine builder:

Ed,
I understand what you are saying and we cut the rod bearings in the lathe to make them work
Thanks,
Scott

[jeffro ra28]

Well thats just ghey. Now you got to make a jig to machine the shells. You'd think lentz could put the tang in the right spot to start with.

[ed]

calico have offered to do it to a new set of bearings for me

+ points to them

cheers
ed

[Celica RA45]

thats why its a pain in the bum to deal with people from overseas ,at least if there is a problem you can hassle them here ,well most times and then they will fix it ,over there forget it

[ed]

yeah, but im still well over AUD$2000 better off
and i gotta say, calico were straight onto it, and are customising the bearings for me no dramas, and minimal delay

that pretty good service i reckon

[jeffro ra28]

Pretty good service considering your not a major wholesaler etc. 10 points to calico

Do they know what is required or do you need to send sample rod?