Broken threads

[BelgiqueBasterd]

I broke the threads in one of the bolt holes that is used to hold the valve cover in place. It's the hole where the 45mm bolt goes in that also goes through the rocker arm axle.

The simples way to fix it would be enlarging it to M8 and retap the thread (I've checked there is plenty of material aroun the hole. But that would also require to drill an 8mm hole in the rockerarm axle. Has anyone done this, or is it as usual a stupid idea of mine?

What are my other options for repairing the damaged threads? I know of the heli coil system, but i als have a couple of other less important boltholes that are damaged wich don't have a lot of material round them so I don't think I could us the heli coils
Any suggestions?

 

[Husa_Busa]

Hi

I highly recommend Heli Coil. It's probably the solution that requires minimum material around the whole. Heli Coil is used as standard in many aluminum applications where you often mount and remount parts. Some parts on the Husey should have had this solution as standard in my opinion, but it cost some money.

Christer

 

[AUSBERG]

Be careful with those rocker cover bolts- there are a couple of slightly different lengths.

I had a friend with a 501 put the wrong length bolt in the outer rocker shaft hole and strip it out because it was the wrong bolt.......

any chance you can get away with engaging unused threads or tapping it deeper with a slightly longer bolt??

 

[BelgiqueBasterd]

Looks like helicoil is the way to go then, just out of intrest how much bigger than the actual needed size does the hole have to be, to be able to fit the helicoil?