HOWEVER, I am determined to get it, at least looking half finished ready for the Stafford show in October 🤞
Cheers, Michael

😂🚨😂

There’s logic in that approach Michael. Once sorted, it stays sorted in your hands. Also, you’re preserving another r/s.
Kev

Aye Michael, it has been suggested that the head gasket let go, you can see that there is a darkened area to the left of the two valves that are salmon tan in colour. This could be the cause of the weak mixture, high temperatures, etc., leading to the granulation of the piston and its failure. Maybe worth checking those mating surfaces for truth etc?

Best, Bill

I think I'd be looking at that complete bike assuming you could hear the engine running*. You could probably flog off the rest of it. As has been said, further horrors are likely to emerge with this one.

Re bead blasting: a long time ago I had a Triumph Stag which was a lovely car. It was let down by the state of the cam covers so I whipped them off and put them in to be bead blasted and powder coated. They did look lovely. A few days later the oil pressure gauge was dancing up and down. What I hadn't realised twas that under one of the covers was some steel mesh to act as a sort of breather filter. This had captured the beads which then found their way all over the engine. There were deep grooves in the oil pump and the engine was effectively a write off.

*Oh, just seen it's been sold for £650. There's another for £800 or offers: https://www.ebay.co.uk/itm/306352937578

Images of the cylinder head from the eBay engine.

That's the weird thing, the cylinder liner, valves, cam all appear to be in "reasonable" condition. Given the actual engine must be at least 40yrs old.
The first thing I thought when I first clocked eyes on it, was oil starvation, but then on closer inspection of everything else, it almost doesn't tally up. 🤷
Then reading the bit from the bloke on farcebook who says he did the same thing to his going from London to Manchester. Maybe it was simply oil starvation. Guess we'll never truly know. Unfortunately it will just take longer and clearly cost me more money to sort.
I had always intended to strip it, to refresh it generally.
Just got to be a case of onwards and upwards. It was always risky buying it blind, but in fairness to the breaker I bought from. He did clearly state that he knew nothing about the history of the engine as he'd bought it as part of a "job lot" from another breaker who was going in to bankruptcy.

I suspect that a weak mixture, poor oil supply/quality/lack of changing and full throttle caused the granulation of the piston and when finally it was starting to break apart it chapped the valves, but by this time it was so metalurgically compromised the resistance to the steel valves was like putty!

I just wonder how much granular aluminium you will find in the sump and maybe smeared on other working and bearing surfaces?

All the best with it.

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