Technical Valve stem broken

[Sunroofjo]

Good morning all, I wonder if anyone can offer up some advice..?
We have a situation with a multipla engine… and we’re not sure where to go to sort it out. Essentially the problem is this; whilst attempting to remove a valve stem, it broke.
We have managed to buy new ones, (& a valve stem puller for future) but what do we do about getting the broken one out?
Would this be something a garage could do, or is it more of an engineering place we need to go to? Or is there a method to getting it out? Any help or advice would be gratefully received! Thanks. (Lots of photos to try and illustrate the problem!)

 

[bugsymike]

Unless someone else comes up with a better solution this would be my method.
Ideally the cylinder head would need to be evenly warmed up, then using a stepped punch that will fit the new guide without catching on the cylinder head when pushing through, I would then use a large copper mallet and with controlled firm blows expect it to drive the broken guide out.
When fitting the new one still with warm cylinder head drive the new guide in to exactly the same height as original was.
If you have access to a garage hydraulic press that would make life easier, as much more controlled.
Failing this then a engine reconditioner/machine shop can do the job, preferably warming cylinder head up first!
I had a machine shop fit some valve seat inserts for me on an aluminium cylinder head some years ago and they did it cold, the result was they fell out less than a 100 miles later.
N.B. Don't overheat cylinder head and it would be wise to check for distortion, if in doubt head should be skimmed to prevent head gasket failure.

 

[Sunroofjo]

Unless someone else comes up with a better solution this would be my method.
Ideally the cylinder head would need to be evenly warmed up, then using a stepped punch that will fit the new guide without catching on the cylinder head when pushing through, I would then use a large copper mallet and with controlled firm blows expect it to drive the broken guide out.
When fitting the new one still with warm cylinder head drive the new guide in to exactly the same height as original was.
If you have access to a garage hydraulic press that would make life easier, as much more controlled.
Failing this then a engine reconditioner/machine shop can do the job, preferably warming cylinder head up first!
I had a machine shop fit some valve seat inserts for me on an aluminium cylinder head some years ago and they did it cold, the result was they fell out less than a 100 miles later.
N.B. Don't overheat cylinder head and it would be wise to check for distortion, if in doubt head should be skimmed to prevent head gasket failure.

Oh heck… that sounds all very tricky, and besides which I am one copper mallet short of the tools required here… If I had such a thing I might be tempted to hit myself over the head with it repeatedly on account of the multipla troubles we have got ourselves into over the years… I like the idea of an ‘engine reconditioning’ place. Although it already sounds expensive… still, we are so deeply in now, digging our way out was never going to be pain free. By way of good news, we do know that the cylinder head is not distorted as we arranged for it to be skimmed and it was declared fine. Thanks for the beautifully written instructions bugsymike, its reassuring that someone has trodden this messy path before us...

 

[Davren]

engineering shop Devon - Google Search

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[Sunroofjo]

engineering shop Devon - Google Search

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Thanks Davren,
We have just had a chat with philspeed engineering and he was really helpful and although he says he could have helped if it was a certain type of engine he says its going to need heating up (as per what bugsymike was saying) and so we are off to see someone he has recommended. Somedays though, I really wish multipla's had never entered my life. Today is just one of those days…!

 

[Sunroofjo]

A little update: we took it to an engineering place in Totnes and the man there seemed to think this was a job for which he had all the necessary know-how and skills to undertake. He mentioned that our son’s problems started by approaching the job from the wrong side (so you don’t pull these things out you push them out) I think that was the jist of it. Anyway, we need to return with it and various components so that it can be done… it will set us back £60 but I think thats a fair exchange to get us out of this latest multipla pickle…