Originally Posted by MarkM

On another note.. while we continue our discussion of hazards associated with working on cars, I was surprised when looking through my MBZ manuals, in preparation for a valve job, to find that the exhaust valves have their core filled with sodium....no, not sodium chloride (table salt)....but pure sodium metal...apparently it acts as a heat sink to protect the valves (neat idea). DO NOT TRY TO ACCESS THIS STUFF BY SAWING OR GRINDING INTO A VALVE....THIS STUFF IS PROBABLY THE MOST DANGEROUS SUBSTANCE IN THE CAR...AND I MEAN REALLY, REALLY DANGEROUS. IT REACTS WITH WATER TO EXPLODE VIOLENTLY SENDING OUT FLAMES, SHRAPNEL, MOLTEN METAL...LEAVE THE EXHAUST VALVES INTACT!!!

MARK