Vacuum testing to diagnose fast idle

[mike657894]

poor compression should be fixed. burnt or bent valve. maybe get lucky and its a bad head gasket. For worn guides you would need to take out the valves mine bent on the way out so got a new set of old style nos for $30. the valves cant grow. seats can be lapped down. but someone willing to do that amount of lapping will probably correct stem length.

 

[Chuck Sea/Tac]

When you say loose valve guides, do you mean worn stem clearance, or not securely attached?

 

[1931 flamingo]

I would think worn stem clearance.
Paul in CT

 

[alexiskai]

Right, like the guides have worn away over time and now there's lateral movement as the valves go up and down, causing them to not perform as desired.

Edit: Wanted to share this response I got from a local "classic car restoration" shop when I emailed them to ask whether they would take on a Model A valve job:

if it’s that old and you do a valve job it normally blows bottom out

So... not gonna use those guys.

 

[Y-Blockhead]

A stock Model A has ~65psi compression and bringing #2 up to specs is certainly not going to "blow the bottom out". I agree, find someone else...