RAY: Now you might think that if he couldn't get premium gas, that would retard the timing and lower the vacuum, and we thought that at first.
TOM: What Ralph discovered was that there was no vacuum.
RAY: There was insufficient vacuum because the valves were too tight.
RAY: And the valves were too tight because this car was designed to burn leaded gas, and the tetra-ethyl lead used to act as a cushion between the valves and the seats. And because leaded gas is no longer available and he's been using regular unleaded in the thing -- he's got a bad case of valve seat recession which makes the valves pound into the seats and reduces the amount ...
TOM: ... We're heading for that I think. Alan Greenspan is sure of it.
RAY: Reduces the amount of play in the valve train and causes, eventually, the valves to get too tight. Hence low compression.
TOM: 'Cos they don't really close.
RAY: Just on the hairy edge. The car still ran, actually ran pretty decently. Being unfamiliar with cars as I am, I didn't know how much power it was supposed to have.
TOM: Yea. None.
RAY: Who's our winner?
TOM: Alisa Para from Santa Fe, New Mexico.
[ Car Talk Puzzler ]