[chris]

Hey everyone,

I finally built a webpage around some pics I took last year detailing the repair of broken cylinder head studs.

Chris

 

[johnypebs]

Chris, interesting piece.
We've touched on this before but here's a bit more detail: A mechanic I know was doing a warranty claim on a 900 monster which had broken two barrel / head studs, both subsequently shearing flush with the crankcase mouth after attempts to remove them. The importer insisted they persist with repair so they tried spark erosion on one which took ages and cost a fortune. Only when told the cost did they cave in and come across with a pair of crankcases. You look as though you were enjoying the challenge but was it an economic repair?

 

[chris]

It took me about 5 or 6 hours of labor in total. The steel plate was $25 or so. The helicoil parts were another $25 or less. And I borrowed the mag base drill for free. Yeah, it was economical. What's the alternative? BUY cases? Then have to split them, buy all new bearings, and reshim all 4 shafts. No way. That's another 5 or 6 hours of labor and $200~300 in parts on top of what I did (not including purchasing cases).

I'm looking into purchasing a mag base drill. If some dealer runs into this problem, they can send me the engine.

 

[Mark1305]

Chris, I'll email you off list with a possible source for leads on a mag base drill.

I'm familiar with them. But oddly enough after three shipyard periods totaling over 12 months of yard time, I've still never seen one in a shipyard.

 

[dj]

Good article Chris! I actually helicoiled one of the studs in the vertical cyclinder when I installed the high-comp pistons. Just like doing exhaust header studs on old VWs. Definately a life-saver.

-dj

 

[dynodave]

Any idea if the factory installed studs are hi strength loctited in, to cause such grief?
???

 

[chris]

I think they are not. And they're not antiseized, either. I think it is dissimilar metal corrosion fusing the threads.