Originally Posted by 1970Chevy
what does the magnetic stand do for the dial indicator or measurement? would I be able to measure what I need to with just a dial indicator ?
If it is a manifold leak (and im almost positive it must be) then how would changine the gears decrease the vacuum as significantly as it does. I understand how a vacuum leak would cause the symptoms the engine has, but why does the gear change double the trouble?
The magnetic stand just lets you put the dial indicator anywhere, except on an aluminum engine.
What gears are we talking about changing. If the timing gears or off the cam can be retarded or advanced from where it should be, this would affect engine vacuum. Changing rear end gears would have no effect on idle vacuum but will change cruise vacuum because the amount of throttle open is changed for the mechanical advantage of the gears.