ok heres the problem ht i got a gsr swap that im building for boost i got cp pistons manley turbo tuff rods arp head studs and all oem gaskets and new water pump oil pump the whole 9 now i took apart my motor compleatly and i found that my crank journals are scored! the bearings are toast!!! did not spin a bearing the motor was running b4 i took it apart so i did not want to machine my crank so i got a good crank off another b18c1 now my ? is how do i determain the main bearing color/size the new crank i got has not been machine its with oem specs so do i go with the code of the block and the numbers and letters off the crank to determin bearing or is there another way of figuring this out please i apreciate the help im trying to build my motor asap

 

ttt

 

ttt help please

 

I just do a plasti gauge to find out the clearances and just order the bearings accordingly?

 

i know i have to plasti gauge but i have a new crank and dont have old bearing to messure with only the old bearing from the old crack that are burnt with cranks in them i dont think its a good idea to put those bearing in my new crank to mess up my journals plus there acl standards FMl

 

take the numbers/letters off the crank and block and select the correct size bearings as a starting point for measurements.

if you have a helms manual you should be able to find this info easily.....if you are trying to assemble it without that manual then good luck to you.

 

yah i got the book but i thougth that once you change your crank your block codes and crank codes no good ?

 

no the codes will still work. they will give you a good starting point. you should still measure though.

 

make sure you follow the torque specs and patterns of tightening. That might of been the problem of the crank journals and bearings got scored. Im on a B18C build myself.