FH - fitting the cylinder head

 Fitting the cylinder head didn't prove to be the routine operation that I had envisaged. I started with a coat of Wellseal on the top of the block and on the top of the gasket. Prior to this I had cleaned out the threads in the block with a new tap and cleaned the threads on the head bolts with a new die. Two of the head bolts were damaged and needed replacement.

Lowering the heavy head into place was the usual faff but eventually I got a couple of the bolts dropped in on the near side. I wanted to put the corresponding bolts in on the far side next but for some reason I couldn't get them to mate with the threats in the barrel. After a lot of messing about I pulled the head off again to have a look:

It's sometimes a challenge when you buy pattern parts - in this case you can see that the bolt pattern in the gasket is wrong and the holes don't line up. I decided, rather than to use the composite gasket in the kit, that I would anneal the original gasket and reuse it. This is very straightforward - it's just a question of heating the copper to cherry red and leaving it to cool followed by a clean up with some Scotchbrite pad.

After that, and a second coat of Wellseal, the head bolts all went in easily. Neither Ariel nor the BSA service sheets indicate a recommended torque for these bolts but they do show a pattern you have to follow when tightening them up:

All that went swimmingly, as expected, and we now have the head fitted. Of course fitting the head opens up whole new set of work faces including the carburettor, the rocker box and the exhaust pipes. OK, the exhausts will have to wait until I have finished the primary case and I'm going to repair the stops on the centre stand as well since access will be better without the pipes in place.

More later.