C172d Venturi

[oracle1]

Hi All,

thanks for letting me join your forum. I am from Australia and I own a C172D which I am very attached to and it is in mint condition. I am looking for an STC to remove my Venturis and replace them with a vacumn pump. My aircraft does not have a drive pad for the pump and I have seen mentions on the net of SA3-664 which allowed the fitment of a belt driven pump. Can anyone tell me if this STC is still available and if I can purchase parts. I am the equivalent of an A&P in America so labour cost is not an issue and I love to work on the aircraft.


regards

George

[Bruce Fenstermacher]

Unfortunately for you I'm pretty sure that STC is not supported any longer as the manufacturer of the pump stopped making it.

You have a 172D with a 0-300-A? Or do you have a 0-300-C?

[oracle1]

I have an 0-300c but i do not want to modify it to accept a drive pad because it still has 800 hours to run and when it dies I plan to install an io-360 continental.

[ghostflyer]

Good luck greeting a approval to put a Continental in your aircraft . Getting a STC is a better way to go . CASA is still in the 18th Century . I am a LAME here and do this as a living . If you want any help let us know . How about a electrical driven vac pump on a STC?

[oracle1]

I have found an STC to install the IO-360 I am also an AME and now sitting my exams for LAME. I've seen the electric vac pump option and I was wondering how much power it will draw and the cost. The aircraft has a JASCO alternator so it may handle the current draw. When i install the io-360 the vacumn will come from the engine driven vac pump but in the meantime I want to remove the venturis because I am cleaning up the aircraft from a drag perspective. The aircraft has an autopilot so it seems a shame to disable the DG and artificial horizon. I also want to do a night rating in the aircraft so the DG and AH need to work. Where in AUS are you? Agreed CASA sucks.

[ghostflyer]

Who is offering a Continetal STC for a 172 C ? The best way to go is a Lycoming Io-360 or a O-360 engine and a lot simplier. Believe it or not the venturies do not produce that much drag. They very robust and never fail.

[Bruce Fenstermacher]

Believe it or not the venturies do not produce that much drag.

I was thinking the same thing about the drag. But of course I've seen a lot of people spend a lot of time and money to get rid of even the smallest drag. And a lot of small improvements in drag can add up to the point of at least 5 mph is gained.

I think that if you want a speedy 170, the venturis just look slow.

[ghostflyer]

They only look slow on RED aeroplanes .And if you want to look fast have a Blue aeroplane

[blueldr]

If you like a SMOOTH running airplane, don't let anyone tout you on to a four banger Lycoming engine as a replacement. They not uglyify the cowling, they shake like a dog sh---ing on the ice when compared to the TCM IO-360 and the don' have as much power either.

[Bruce Fenstermacher]

They only look slow on RED aeroplanes .And if you want to look fast have a Blue aeroplane

Nice to know it doesn't matter if you have an airplane or an aeroplane, RED is still slow.

[GAHorn]

They only look slow on RED aeroplanes .And if you want to look fast have a Blue aeroplane

That is true. They only LOOK slow on red airplanes. Red airplanes easily overcome the insignificant drag of venturiis.

Green airplanes don't go fast enough to create drag...therefore venturiis are not a problem on them either!

Seriously.... You've gotta be kidding! You're worried about the DRAG of venturiis? What about the drag of the added paraphernalia of belt-driven vacuum pumps? Not to mention the failure rate of vacuum pumps!

You really should spend your thinking time on a different subject. Venturiis are dirt simple/reliable/trouble-free. WHY do you want to spend good money creating maintenance headaches for yourself?

[oracle1]

If you like a SMOOTH running airplane, don't let anyone tout you on to a four banger Lycoming engine as a replacement.

I'm on to it I want the six cylinder and I have spoken to Tom Anderson on the phone. His conversion is the one I want. Would appreciate any info from anyone who has done it. Bluedrvr I know that you have done it from reading previous posts. I don't care if its a pain to do it I enjoy engine transplants. You can keep your original mufflers and the cowl is unmarked.


Ghost flyer how much would it cost to buy an electric vac pump and STC? Does it include the removal of the venturi in the STC?

STC here

http://www.thelandinggearworks.com/powe ... onversion/

[oracle1]

Considering I'm going to fit flap gap and aileron gap seals, Hoerner wingtips, strut fairings, Knots to u wheel spats, door stewards so I can take the metal fittings out from under the wings and a K&N oiled cotton filter yes I do want to remove the venturis. I already have a Dynon EFIS fitted so reliabilty is not an issue. Eventually a glass panel will go in and the vacumn system will be serving as a backup. I use the machine as a work vehicle and I fly 360 nautical miles per week. Every knot and every litre counts. As for reliability I have already had ants make a nest in the venturis and lower my suction and I need to strip them, all systems cost money and time. Until I get the IO-360 any vacumn solution will be temporary as the IO-360 will have a drive pad. The venturis also dont run up properly till airborne which could be a problem at night.

[bagarre]

I use the machine as a work vehicle and I fly 360 nautical miles per week. Every knot and every litre counts. .

All the speed mods mentioned might have given you maybe 5 or 10 mph gain?
The IO-360 won't save you any liters, that's for sure.

You should consider a Mooney

I thought about moving further away from the office and aero commuting a few times a week to a local airport.
If I was to do it, I'd pick up an RV-3 or RV-4 with an autopilot as a second plane. Can't get much more efficient in speed and fuel than that.

[blueldr]

oracle1,
I did use Tom Andersons STC when I converted to the IO-360. However, My exhaust system was very old and really pretty well worn out. In view of that, I elected to have a new exhaust system built by a local exhaust manufacturer rather than buying a new standard exhaust and then havung to modify it to fit the IO-360 engine and installation configuration. I also reversed the top intake system to provide better clearance for the intake pipes from the front of the top cowling.
Being a confirmed bootlegger, I did not even attempt to get any kind of approval for my exhaust systen or the 180 degree rotation of the intake system. It worked beautifully and had a great sound. I just figured that no one would ever know what configuration the STC called for, the conversion being relatively rare.