Sir Elgamore (my daughter Amy's Classic Mini decided to misbehave) He was running poorly and we have the London to Brighton Mini run on Sunday. After trying all the usual things and having only recently been serviced I was perplexed. When I compression tested him cylinder 3 was right down. So a blown head gasket I thought, no it seems one of his exhaust valves has decided to shat itself. There is a lump missing as you can see from the pics. good news is the rest of the engine is undamaged. Luckily I have a rebuilt cylinder head for Oly Emily's (my youngest daughter's) Mini so I will borrow that. Will I get it done for Brighton?, I will give it a ruddy good go!
Don't know what caused it to fail but looking at the other valves the mixture was bang on.