Main Cap

Found Broken Main Cap In My Kb Today, Bearing Looks Fine, Cap Broke Thru Center Of Bolt Hole, If I Put Another Main Cap On Will I Have To Line Hone Or Is This Something That Is Ok To Do. I Know I Need To Have Crank Checked Because Something Had To Cause This To Happen. Motor Had 40-50 Passes And Ran Perfect. Maybe Main Cap Sometimes Break? Thanks

 

yes on the line hone
check the main studs for stretch also

 

check for signs of detenation this will also cause the failure and hone it fore sure and just replace the studs they must have been beaten up

 

For sure line hone it whatever caps you end up using. I often wondered if tire shake and just regualr use caused cracked caps...not sure though.

Sorry to take this opportunity to throw an ad in here...but if you need a set of aluminum main caps I have a complete KB set for $200 - KB #7269. I no longer have a block that they'll fit.

 

Cracked Cap

If you have a KB with 2 differnt length side bolts and you put the long bolt where the short one goes you will crack the cap every time

 

We had the same thing happen on our BAE....Line hone for sure but there was nothing wrong anywhere else. Just a stressed cap.