Bulent Aliev wrote:

Hi All,
I was glad to see at Shady Bend that Dave Atkins is using the stock air
pump from the RX-7 to power his vacuum instruments. He told me that
works very well and the pump is producing about 16" vacuum and he has to
bring it down to useful 5-6". I also think if the pulley is made larger
to slow down the RPM of the pump will be beneficial.
On the down side when the air pumps fail, they lock up.  I noticed an
air pump on 20B with electric clutch, which can help in case of pump
lock-up?
Bulent

Jeff Spitzer wrote:

I plan to use the stock air pump for vacuum.  My approach to the failure
mode is to simply isolate the belts with suitable vented covers and
separators.  Then if the thing seizes it busts or burns the belt with no
further damage.  If a belt driven access. fails and takes out the water
pump belt then a small emergency becomes a big one.

Jeff Spitzer

 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org