Jae,

It's a sad story. Parker-Hannifin (Airborne) had an STC'd kit (Airborne kit number 312) for installing a belt-driven dry vacuum pump in Cessna 170B, 172, 172A, 172B, 172C, 172D, 172E, and 172F models with Continental C145-2, C-145-2H, O-300-A, O-300-B, and O-300-C engines. About four years ago, when Airborne stopped making vacuum pumps because of liability concerns, they quit selling the kit. I've searched high and low for a "new old stock" kit, and can't find one anywhere. Used kits do pop up at salvage yards from time to time.

The STCs that covered this kit are SA15CE, SA3-664, and SA3-663.

There are electric motor powered vacuum pumps on the market, but the current draw for the electric motor in these systems is 12 - 15 amps, and with a DC generator system and the engine at idle, the motor can deplete your battery in no time.

Finally, you could install electrically driven gyros (about an amp each) instead of vacuum gyros. Electric gyros start at about US$1500 each.

I did the Jasco alternator upgrade on my '56 172 two years ago.  I love it, I can power everything in the plane and have pleanty of power left.  I have Nu-Lites behind ALL the instruments in the panel, I regularly pull 20 amps while in flight.

    Dave

Hi Stan,  I had an old castiron airborne vac  that could not be repaired in my 62 172.  I could not find a replacement for the vac and put on the Venturi.  I still have not found a salvage yard vac.  Do you know of anyone who makes a vac that I could stc to a belt drive?   I just need the vac.    Thanks,  Ron

Hi Stan,  You are a life saver.  I talked to Spruce and Cheif and Arizona they all  said I was out of luck.  Thats the one I thought I needed.  Thanks,  Ron

There is another way out of your delema. You can upgrade your engine form a 0-300 a,b,c to an 0-300 D. You have to split the cases and change the starter drive pin to a bearing and then put on a 90 degree starter drive with the vac pump drive. It is a bit of work but easy to get through the FAA on a 337 and you get rid of the pull cable start.
Just another way to skin an old cat. I have to admit, I kept my venturi system because they never fail and for the cost of a pump they arn't too ugly after all.(it is fun to have the young pilots ask if it's a horn)

I have the 0-300-D change in my 63 172 and love it.  I would say that it is definitely worth the cost if you do it during overhaul but if you're not there, you may want to just stick with the venturi's until OH time.

Bruce Cook
USMC (ret)
Support Search and Rescue.....Get Lost!!!!!!

I've seen the design of a C172 with two venturis.  One venturi supplied the DG and the other the AI.

As far as icing up, you shouldn't fly into know icing conditions, but if you are referring to icing due to the temperature change as the air accelerates through the venturi, I'm not sure.  Warmer air is being drawn into the venturi via the vacuum system, which might be enough to offset the temperature decrease.

As far as IFR, they got be reliable in flight, The downside is you have to wait for them to spin up on your takeoff roll.  Additionally, you will not know it if it is working until you are airborne and close to the ground. If the clouds are low and you are not ready it could make for an interesting afternoon. Having said that any system could fail upon takeoff, its just that with an electric or engine driven vaccum you will at least know it is working before you take off.

My two cents...

Stan, just a blast from the past, back in 2005 when you posted information on the C172 vacuum pump modification,an Airborne 212CW-6  type pump.
Spruce still have the 212CW pumps, made by Rabco. What I would like to know. is the drive shaft in the standard 212 pump a spiggot shaft and if so how hard is it to fit my pulley off my pump onto one of Spruce's pumps?
Thank Mark

Lacey,

I had success with Mark Gaulke at Rabco Pumps. he can be contacted on
800 527-2726 or cell 414 807-6778  ( US Numbers). Hope this is of some help.
Your other source will be Aerostock in france who have a couple of new pumps still in stock. Look them up on the web at 

www.aerostock.fr

Best of Luck

Mark

LOOKING FOR A KIT TO CONVERT A 1958 C-172 FROM VENTURY TO ENGINE DRIVEN VACUMN PUMP. STC # SA3-664 USING A 212 CW-6.CALL STEVE @ 816-809-5655