was just out for th afternoon at a the local dyno shop, guy we knew brought in a 540 merlin with dart heads on alcy. Bought it used from another racer
4th pull made 893 hp at 6500 rpm, nice big power , 5th pull they changed the plugs and nothig else and blew an exaust valve right out of the back of the shop, happy days, pulled the head off and it caused amazingly little damage needs a piston marked up the head etc and bore some but still for how it came apart not too bad. such is the risk of buying a used race engine