So we are getting closer to fitting the block and pistons... First job, polish the block.
But first of all, remember that broken fin?
Well, here it is again. It has been built up with weld (small TIG torch) by a very clever man called Steve at Bernard Ashpole's:
And later, having years of cr@p cleaned out of it. This debris has been removed bay various bent wire tools, poking out all the areas between the fins, the pushrod tunnels, and between the cylinders. It's a complex casting, I would love to have seen the core for it:
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And here it is today, polished as it was when it left the factory. You can see the honing marks Ashpole's left:
Next stop, and before I forget to put them back, the tappet blocks. Here is one of the three good ones - one of them came out in several pieces.
Here are two of the tappets. The groove is for a small wire circlip which serves to retain the tappet in the tappet block. This appears to be an assembly aid, since it stops the tappets falling out of the block when you lower the cylinders into place.
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This is the new one from Drags:
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With their tab washers & nuts:
Hi Charlie, I am in Minneapolis, USA. I am restoring a square four myself. It is a bitsa bike with a 1948 frame and 1937 engine. The bike seems fairly complete but my first problem was that the kick starter was not able to turn the engine over. Guess what we found out? The mainshaft in this bike is built of two pieces (the long rod and a sleeve like ending which fits the clutch side). The mainshaft rod was freely rotating inside the sleeve. That is the reason the kick was not engaging the engine. Do you know if I can find a SQ4 mainshfat somewhere? Or do you have any recommendations for me? Thanks a lot, Kumar
ReplyDeleteHi Kumar,
ReplyDeleteThanks for your comment. Have you read my post 'Spend a Night in the Box'? There is a picture showing the kickstart pinion & ratchet mechanism - have a look at that, make sure there isn't something missing! There is also an exploded diagram of the gearbox - it's not too good a picture but it might help you.