I haven't a clue. I'm sure I've never bought one in my life but I seem to have a drawer full of them.

This is the second engine (I haven't yet tested the first for leaks) and the cam gear looks very nice. The hole I drilled in the firewall so that I could get at the tab washer on the cam damper wouldn't have been necessary with this engine - someone had in its place put a shake-proof washer. Three cheers for Captain Sensible.

Then, with the head off, a quick glance at the bores revealed some very slight surface rusting (probably caused by my less than careful pressure washing) and no carbon ridge to speak of at the top. I don't think this engine has been far since its rebuild by BMC. The sump came off next....

... and there were no horror stories in there either. That revealed the crank, mains and big-ends, all of which seemed to be in good order.

At this point, Awkward put his head round the door to ask why I was bothering to try to bodge a repair on the first engine when I had a couple of spares and knowing that I would have to take the first engine out at some point to do the repair job properly. Well, I don't really know anything about the other two engines; they could be equally damaged and, after showing the second crankcase the wire brush, the repair scheme may not be such a waste of time...

It's impossible to tell what's going on here. They could be blow holes in the casting or worse - who knows? Anyway, I'm persevering with the repair and, if it works, it's got to last only 2000 miles.

So while I was waiting for the epoxy to go off, I put a couple of extra braces in the turtle deck and, with The Ambassador's Daughter hanging on to the other end of an 8ft sheet of aluminium, cut out the first panel and got going on the difficult bit.

And then it was time to test the new repair. After filing everything smooth and square, I put back on the engine as little as it took to test the water system. And with the radiator and block filling up, out came the water from the repair. I thought it might have been the head gasket and just added a couple of extra pounds on the head nuts but it didn't make any difference. Well, that was disappointing. Having wasted a week on the block - there was always a chance that it could have worked - it was time to call it a day and whip the engine out.

I'm pleased to say that all I needed to do was undo the bolts on the bell housing and the four bolts on the front mounting, disconnect a couple of earth straps; pull the engine forward so that I could undo the bolts holding the clutch diaphragm and then lift the block out. And, if I make a slight alteration to the radiator mount, I'll be able to put the next block in with the clutch attached to the flywheel.

I don't like to throw in the towel but the first block was beginning to hold me up.