And then it went Bang

[Speedex750]

Hard lines Charles, it's a sickening feeling isn't it? I did mine almost exactly the same a couple of years back pulling the front bit of flange and No1 cylinder off the block and ripping bits of crankcase up with the rearwards block studs, a few of which were snapped. I shut the garage door and didn't look at again for a month. There was a thread running then speculating what causes this; unfortunately you and I aren't the only ones to have experienced this.

With hindsight mine only had about 120 miles on a rebore, it seemed to be going so well up to that point, and I think maybe the solid skirt pistons gripped the bores that maybe were a few thou too tight not reflecting the pistons in them. Also the stickyness of Loctite 515 or 518 came out of the subsequent discussion and the expired engine, again with hindsight, probably didn't have a very good block to crankcase gasket and may have been a bit soggy after juggling the thickness setting the deck height - allowing initial movement.

I now know why you started the thread about extra holding down studs! In addition to what was said on that thread, on the normal 8 studs I use 1/4" thick washers to maximise the grip length, spring washers and Loctite'd nuts with Allen headed bolts front and back in case insitu tightening is needed (hasn't so far).

Commiserations,  Dave