Bob try this might work for you
Kevin B
SNF's Most Significant: Aero Advantage Dual Vacuum Pump
We often write about interesting items we've come across at shows. We also will bring you many more really cool things, found at the show; but right now, we don't want to wait with this proclamation:
The most-significant new item seen at Sun 'n Fun was the Aero Advantage Dual Vacuum Pump.
The pump, which should be STC'd and PMA'd by this Fall, contains two separate rotor systems. It has a single inlet, and a single outlet, and is thus "transparent" to the aircraft. It requires no switching, and is thus "transparent" to the pilot, as well.
The vacuum pump, which is assembled in Texas, is slightly bigger than the standard unit: it's about 2" longer, and weighs a pound and a quarter more; but it provides redundancy to run your vacuum instruments.
The pump has additional features that make it a good idea: its output is rpm-related; it won't lose vacuum, as you rev up the engine. The rotors are pinned to the single-piece driveshaft (no couplings) with shear pins, that are designed to break, without doing damage to the driveshaft (and thus to the other side's functionality). [The driveshaft, of course, has a neck-down at the driven end, so a total failure won't damage the rest of your engine --ed.]
It uses a fail-safe internal valving, so that, in the event of one side's failure, your instruments will continue to work as though nothing happened. The only thing you'll notice will be a little red light.
When you fire up your aircraft, two little red diodes light up, to tell you that both vacuum pumps (in the one housing) are doing their jobs. The lights go out momentarily, as you pass through about 1200 rpm -- they're on at <3.5" Hg. (You don't want little red lights to be constantly "on," in your cockpit.) Should something go wrong with one part of the pump, its corresponding little red light would then go on, telling you that you're now down to one system (as you were, before you installed this pump). For reference, at 2700rpm, the Aero Advantage pump moves about 12 cfm.
Deliveries for Experimentals will start just before Oshkosh. The company is taking orders, at $695, for the pump -- that price is expected to cover orders taken now. The pump will be the same; it will come with, or without, the pedigree, depending on how soon you need it...
FMI:
www.AeroAdvantage.com