79 1200 cyl head woes

Paul LeClair said:
Andy has been quite restrained in his comments concerning the results of his having sent the head to Lance for overhaul, the new  valves seized in the new guides almost immediately due to improper valve/guide clearance, then the head has had significant valve recession issues ever since, as you said the then new valve seats may not even have been the correct hardened seats..., which makes it tougher now as they probably need to be replaced but the crack in the iron skull makes that an issue.
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Yes - dealing with Lance and the aftermath of his work on my cyl head has been a challenge.  But I do love riding this 1200 so I am going to persevere to get it fixed right. 

The cracks appear to be in the skull only - not in the seats or in the head alloy material.  I am going to ship the head to someone who can deal with it, just need to get a few more items sorted with other bits before sending the parts off.

Thanks for all the insight and advice - this is new ground for me and I appreciate the group sharing their collective wisdom.

Cheers,
Andy
 
Hi Andy,
Just for the record, the original head from my RGA developed 4 cracks like that in the skulls - one from each exhaust seat to the edge and one between inlet and exhaust. It's a one owner bike so I know that the head was totally as it left the factory, aside from around 60,000km of fairly easy life at that point.  So it may well have been Lance buggering up the job, but it also may not.
I'll be interested to know how you get on with it since I still have that head and it's still got the cracks.  I discovered it in about 1996 and it wasn't too hard or overly expensive to source another, although just as happens now, that one turned out to be problematic too.  Rectified by Red in the end, I believe it was the very first Laverda head he and Ollie did.  Makes it a collectors item.  :D
Cheers
SteveB
 
Here is a photo of my 1200 head showing the crack. Has been ceramic coated as well.

P2180940_zpse6796076.jpg
 
These head sagas come up more and more.I fear they will defeat people who will not bother with shipping heads halfway round the world...is it not worthwhile for dealers to stock some reconned heads for sale, perhaps on a part ex basis? As mentioned , buying another second hand head may not work...I did that and though it looked good it had been badly unevenly faced and was scrap.Seems more of an issue than any other component. Hey, maybe the owners clubs could help....
 
Not had any experience with laser welding.

However, long ago I worked for a joint that got exotic dissimilar alloys electron beam welded for high vacuum and high temperature work.

The penetration and fusion was great on parts that were a light press fit, so I wonder how it would go with these sorts of cracks.

Sounds like this forum could get a bulk discount !
 
Piet has had several parts laser welded for me.
Great way to save a part that can't tolerate heat distortion.
I have not had a head repaired but if Piet says it's do-able then I trust his judgement.
 
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