KH Crankcases

[robjameson]

The observant among you will notice an absence of my 1954 KH this season.

The reason for this begins with me finding that the engine had wet sumped over the winter, something I found a little odd since I have a one way valve in the feed.

One day I decided to remove the valve to clean it (which is a good job because it had a large blob of RTV holding it open, that problem was easily solved). Sadly, in my haste to remove the one way valve from the crankcase, I caught the jaw of the spanner on the return banjo and pushed the bolt out of the side of the cases.

Next I said words to the effect of ‘oh dear, I wish I hadn’t done that, you very silly man’, and promptly abandoned the bike in the back of the garage in disgrace.

Having spoken to a prominent member, it was suggested I might be able to repair it with epoxy, which he had seen before - I attempted this but it did not work, partly due to poor access.

So this weekend, I went about removing the complete engine and photographing the problem, sending the images to a well known welder, who confirmed I would need to strip back down to crankcases! Bugger!

[robjameson]

Engine stripped!

[dave.owen]

Looks nice and clean inside

[robjameson]

I should hope so, only done 800 miles since I rebuilt it!

[David Smith]

Rob
Very sorry to hear this, the whole area is a disaster as far as access is concerned, Hopefully the job will be stronger than original when welded up and at least the engine should go back together with no problem

Regards


Dave Smith

[jj.palmer]

Rob sorry to hear of your problem, let it be a warning to us all.

Just a suggestion, would it be better to bolt the two half casings together, even maybe with the crank shaft in situ, prior to welding, this would hold the casing much more rigidly to avoid any thermal distortion when welding.

John P.

[nevhunter]

In that location welding is not likely to cause much distortion especially if the case is well preheated. Build up a new piece of metal rather than use any of the little bits. It's not a difficult weld for a good aluminium welder with TIG. Done properly that case will be as good as new Nev

[dave.owen]

Rob, there is a set of crankcases on ebay might be cheaper than getting yours welded

[paul.jameson]

I still cannot believe that there was no previous damage to those cases. I know you are now a lot stronger than I am, but at my best I would have struggled to do that amount of damage with over - enthusiastic use of a spanner.

[robjameson]

Rob sorry to hear of your problem, let it be a warning to us all.

Just a suggestion, would it be better to bolt the two half casings together, even maybe with the crank shaft in situ, prior to welding, this would hold the casing much more rigidly to avoid any thermal distortion when welding.

John P.

That was my thought, however on speaking to the person doing the work, he wanted it fully stripped so I will go with his advice.