I just toyed with an electrically driven vacuum pump for the instruments.
Trial one and two:
A like new vacuum pump operated at by a big drill press (1.5 HP):
2100 RPM resulted in enough vacuum to run the attitude gyro at minimum
suction on the gage (4.5 "Hg. at sea level - so not enough at altitude.)
2500 RPM - the next belt setting - resulted briefly in enough vacuum - I
think - and then the unlabeled breaker in my surge protector popped.
Trial three:
12 Volt electric motor from the surplus place, 1 3/4 " O.D. by 2 1/2 " long
permanent magnet like the biggest I have ever seen in a model boat. Hooked
it up to a 12 Volt battery, burnt my finger with the wire going to it -
didn't get up to RPM anyways - smelled like amps.

Conclusion:
Rats, I'm thinking electric gyros now.

regards

Marko Bewersdorff
Rotary Long EZ in the works.