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Rocker box broke..

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Hi all 

The rocker box on my 1936 Model 18 has sheared. There was a hair line crack in it that was welded up but on my last run I was burbling down the A217 and the whole front of the assembly (being open valves it's not really a box) sheared off and was left hanging by the valve lifter cable. I attach a picture of the result.  The state of the surfaces shows that the crack must have been there for ages. I'm getting it repaired to get her back on the road but in the meantime am looking around to see if I can find a replacement. The open valve arrangement I believe stopped in 1938. Is there any interchangeability with later rocker assemblies? I've also attached a picture of what it should look like.

 If I were to get a later head and rockers would it fit on existing barrels? Is the spigot and bolt arrangement the same pre and post 38? All a bit depressing as she's running better than ever otherwise. Ho hum. 

Has anyone has a open valve rocker assembly being used as a paperweight?

Thanks 

John

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There's a lot of force levering that apart and it looks as though the weld was quite superficial with no real depth to it. If you vee it out well and get a good welder to do it that should help.

I would probably consider boring it out where the rocker shaft / bushes go through and fit steel sleeves for the bushes to work on as that would reduce the force on the weld.

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Hi Ian, now that the casing has actually broken it can be vee'ed out properly and hopefully a good weld will hold. Interesting idea about the steel sleeves which I will pass on... thanks

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.. but I was only thinking about 1/16" or so.

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Hello this looks to me that the welling has not penetrated this crack very well and if any one needs alloy welding done I know of a good welder that makes a top job of alloy welding in near by Goole its JJ Malone welding and engineering services yours. Anna. J 

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Thanks Anna, yes, it's clear that the repair weld only papered over the cracks. I'm waiting for a verdict from a local welder in Surrey who specialises in welding alloy auto parts but if he can't help I'll contact JJ Malone. 

Thanks again

John

 


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