Calling 914 users.......

[Guest Maj Millard]

I'd be interested in hearing from people on their experiences with the 914 Turbo, and getting a thread going on them. I may have to maintain another one soon on a Gyro, and after familiarizing myself once again with the sytems from the manuals, it appears they have taken a really good engine, and made it about as complicated as they could have.

 

I am familiar with turbos on aircraft engines, as I have worked with them many times over the years on such things as Chieftains, Ag Huskys, Cessnas 300 and 400 series. Most of those are relativly simple installations, with mainly mechanical type wastegate controllers.

 

The 914 system however appears to be about as electronically complicated as they could make it, and is probabily equally on par with any system fitted to a Porsche, BMW, or Mercedes which would just, in my books, make it about as potentially troublesome and unreliable, not to mention costly to service and fix, as any systems on any of the above ?..................................

 

 

[Guest 172M]

Add to that the extra 15 hp rated only for 5 mins!! Unless you are operating hot and high, why bother! We do hot here, high,7500 ft isn't high! And don't forget it is based on the old 80 HP 912 not the larger ci 912S, and the 912S is now out to 1800 Hrs TBO

 

FWIW

 

 

[HEON]

Oh please, oh please, oh please get the computer diagnostic system up and running. It has proven too hard in SEQld, and Flood's must think so to. Relates to a previous comment of mine when you seemed surprised when I commented on poor 914 support.

 

In my understanding it is only way to fully check on turbo sensors...get it ...let me know...will visit!

 

 

[Guest basscheffers]

Add to that the extra 15 hp rated only for 5 mins!! Unless you are operating hot and high, why bother!

You'll always have a lot more power than a 912; after those 5 minutes you can continuously run it at 100HP and the turbo makes sure that extra power is available even at altitude. You can get 115HP out of it up to 8,000ft and 100HP continuous up to 16,000ft.

Or cruise more economically at lower power settings.

 

If your airframe can take it and you want to go faster and/or higher, you certainly will.

 

 

[Guest 172M]

How often do you fly @8k(good cabin heat!!) and over 10k, 02 would have to be a consideration added to the airframe would probably punch you over MTOW or loose a pax or gear)as previously stated unless you need to deal with very hot and very high i.e. over 45c and operate# 9 or10k why go the complex route? The turbo is still 1200TBO agnst 1800TBO 912s...........Do you need the potetentially marginal gains with ceiling limit in place?Below abt 7k msl the gains of the turbo is gated to the atmosphere as the system does not require "pumping "to breath .Self compensating carbs, as fitted, are good to 8-9k with no issues, for continuous ops at high altitudes jetting is available!

 

FWIW

 

 

[Guest Maj Millard]

Frankly folks I have my doubts the 914 would even make 1200 trouble free hours...not on the engine side of things....but due to the turbo itself. There is only 4 thou clearance between rotor to housing, and no repair capability on the turbo itself at all...it's a throw away item, and then you put out for a new one....at what cost ?? any one had a price quote lately.

 

The whole electrical side of things reminds me unfortunatly of the VW type 3 & 4 engine episodes (early fool-injection) and most of them ended up at the wreckers within a year or two..................

 

 

[facthunter]

Turbo charged aero engines.

 

Primarily designed for high altitudes. In this engine perhaps it is a way to just get more power. The best way is to make the engine bigger in displacement. This is not possible with the Rotax without a complete redesign. Simplicity is the essence of reliability in aero engines. I had a twin Commanche that was turbo charged and the engines, although nominally Lycoming 0-320's, were entirely different to the normal ones that you see around. They had beefier cylinders, stronger crankcases and oil jets spraying on the pistons (underneath) even though the engines had NO horsepower increase. it just maintained it to about 12,000 feet ...Nev.

 

 

[bones]

Frankly folks I have my doubts the 914 would even make 1200 trouble free hours...not on the engine side of things....but due to the turbo itself. There is only 4 thou clearance between rotor to housing, and no repair capability on the turbo itself at all...it's a throw away item, and then you put out for a new one....at what cost ?? any one had a price quote lately.The whole electrical side of things reminds me unfortunatly of the VW type 3 & 4 engine episodes (early fool-injection) and most of them ended up at the wreckers within a year or two..................

Well first off i know of at least 3 of 914 with over 1500 hrs and not a spanner on any thing, this is in gyros too, the motor definately works harder in them than a FW.

 

I agree with you about the electric side of it, this is why the Xenon uses the other method and gets more hp, for no complications. This is also why if there is one little bit of trouble with the motor i got in the shed, i am going to rip all that crap off and stick a waste gate on it and be done with it.

 

Maj, How long before the machine will be able to go down to you as Tom rang me a couple of nights ago and asked if it can stay here til things get sorted out down there? What ever that ment.

 

Feel free to contact for details on different bits of how the machine works ect if you need, i will organise and slip down and see all you fellas one day, just give me the co ords of the field on pm if you wouldnt mind.

 

 

[Yenn]

Black Rod. Your comment "Pity somebody like Honda didn't get into light aviation engines" was answered several years ago Both Honda and Porsche were getting int aero engines. Porsche bailed out and Honda seem to have just gone very quiet.

 

What we really need is a good compression ignition engine, which has been a long time coming.

 

 

[Spin]

What we really need is a good compression ignition engine, which has been a long time coming.

Here, here - been quite a few disappointments on that score. I remember reading and getting excited about the Zoche radial diesel back in the early '90s, but it doesn't seem to have come any closer to being a practical reality.

 

 

[Guest Maj Millard]

Bones, Those three 914s you mention are doing pretty good considering the latest info that I read the other day indicates a 1200 hr TBO, or 12 years, whichever comes first !!...........

 

Years ago Iwas working for a mob that had a Turbo equipped, Piper Arrow on line, for rental.

 

One day a bloke took off in it, but shortly after reappeared back in the pattern, and landed.

 

He said not long after takeoff she had missed a few beats, and then seemed down on power, although it still ran ok. On checking the turbo inlet, it was obvious that the inlet turbo impeller (the alloy one) had completely destroyed itself, and only the bare shaft was left. The engine had completely injested all the bits, and spat them out!. The oil filter had minimal metal in it. There was almost no metal in the cylinders, and scratches on the curves in the exhaust pipes showed where the exiting bits of impeller had been ejected.

 

 

[bones]

Maj,

 

Dont get me wrong i have heard of some horror stories about 914's too, but i guess it is the luck of the draw with them but the 912's IMHO are absolutely bullet proof, and this is why we have gone the way of the no elec turbo, it just takes all the crap out of the situation

 

 

[Guest Maj Millard]

Love the 912 myself. Seems like a lot potential problems for just another 15 Hp on the 914. The wastegate is what controls the boost, and guards against overboost. But with a good Manifold pres/ boost guage it is possible to manually set boost pressure................the jury is still out for me !!