Anybody know the actual dimension of SBT undersize bearings?

[BMANN06]

I need to take my rod journals down (probably to 2nd undersize) and mains to 1st undersize. I'm trying to find out what the actual dimenisons the sbt kit comes with you get 2nd over/1st over/Standard/1st under/2nd under with the kit. Ditto on the rod bearing kit.

I need at least .25mm/0.001" for the mains and .50mm/0.02" for rod journals.

Can someone help me out?

 

[Dr Honda]

That's a great question.....


Unfortunately... I don't know what the new crank spec needs to be.

But, with that said... I've done enough other "Solid bearing" engines over the years to know... Call the manufacture. They will give you the new Journal spec. And... most importantly... if there should be a chamfer, and how big it needs to be. (where the journal meets the crank web)

With the bearings... you need them in spec, and in tolerance... other wise you could crash the bearing, spin the bearing... or have almost no oil pressure.


But, once you call STB... please post up what they say, so we will know for next time.

 

[BMANN06]

Hey Doc thanks for reply, after speaking with tech @ SBT

1st Undersize = 0.0005"
2nd Undersize = 0.001"

Unfortunately my journals are scored up well beyond those specs so I've decided to add this crank to my parts bin for now and just get a new one. I spoke with CVTech in Quebec they indicated they can weld (ie add metal) to the journal and then machine it back down to standard.