B18b1 cam bolt broke inside deep side what size of heli coil do I use

 

8mm x 1.25 pitch... however, the reason that the bolt broke is because it was too long, so leaving a piece inside the cam will set you up for the same problem again. You MUST extract the bolt before repairing the camshaft end. B18B cams are plentiful and cheap... why don't you replace it ?

 

Thank you so much, I’m going totry my best getting it out if not I’ll just look for another.

 

Can I use a b18a1 head?