dbsharp

Some of my main bolts chatter while torquing them. I cleaned the bolts and the threads in the block and lube it all up with plenty of 30 weight oil and it still chatters! I was thinking that I might want to try using a tap to clean up the threads in the block. Anyone experienced this before?

dbsharp

Running a tap solved the chattering issue. I used a M11x1.5 tap. Major diameter on the bolt is about 10.8mm. The bolts felt a little on the loose side but nothing appears to have yielded. Next time i have to do this I want to find the correct tap with the right tolerances.

Now to measure the mains and get this thing running!

welfarepc

good job to update with your solution.

i would also suggest using Moly lube next time.

Bailhatch

I don't think a tap is really the right tool for that. Taps are for cutting threads, not cleaning them. Next time get a thread chaser or at least use a worn out tap.

Scott_Tucker

Or use a thread forming tap since the threads were already there. This type of tap doesn't cut metal, it just deforms it so it does not create stress risers. You should be OK on your main caps though.