Thank you for referral

John spends his summers up at his camp in Wisconsin, and comes back in October. If he's not available, I can be with some advance notice, here in Fort Lauderdale.

Yea looks like John isn't back til very end of the year. He doesn't have any other recomendations.

Glenn- I'd be interested in working
with you if you could fit me in!


Tommy

Yea looks like John isn't back til very end of the year. He doesn't have any other recomendations.

Glenn- I'd be interested in working
with you if you could fit me in!


Tommy

Any issues on the turbo installation? I am referencing problems on the twin Cessna with exhausts being broken and cutting through wing spars or engine fires.

I seem to recall the issues with turbo-ed twin Cessnas is that the turbos are mounted to the airframe and not the engine.

Best,
Rich

Aztecs used three basic turbo systems over the years with some slight variations.

The STCed RAYJAY turbo normalizer system uses dual turbos and two manually adjustable waste gates actuated by a split vernier control. They are operator limited to 30” but can pull sea level power into the teens.

It uses an induction airbox that has a balanced flapper that automatically closes off the lower pressure side

The drawbacks are parts availability, cost of OH and higher CHTs mainly due to lack of inter coolers.

The benefits are non or low boosted takeoffs so a turbo, waste gate or induction pipe failure is not effectively an engine failure. The higher compression pistons are retained and the TBO is still 2000 hrs. Higher CHTs when boosted usually results in more cylinder head cracking.

They utilize an accessory scavenge pump and a separate turbo oil system filter. The exhaust pipes are robust but the wastegate actuating system is poorly designed.

The factory system that was available on the C and D is an electric actuated “on/off” system that is also turbo normalizing. They utilize a single larger turbo and work well but are very hard to source parts for. They have a different cowling design and have an additional pair of cowl flaps. Recommend TBO is reduced to 2000 hrs.

The factory optional E/F Airesearch system is boosted to achieve rated 250 HP with lower compression pistons. It utilizes a density controller, larger cowl flaps, 1200 series mags, and piston cooling oil spray jets.

They are typically reliable and have better parts availability. The induction air is taken from the front cowl inlets that are slightly enlarged instead of a separate lower inlet scoop.

The Turbo systems don’t seem to have blow out issues as everything is forward of the firewall and mounted to the engines so they move in unison. The normally aspirated aircraft have issues with the forward exhaust cross over burning the fiberglass nose bowls. None of the turbo models have that problem.

Aztecs used three basic turbo systems over the years with some slight variations.

The STCed RAYJAY turbo normalizer system uses dual turbos and two manually adjustable waste gates actuated by a split vernier control. They are operator limited to 30” but can pull sea level power into the teens.

It uses an induction airbox that has a balanced flapper that automatically closes off the lower pressure side

The drawbacks are parts availability, cost of OH and higher CHTs mainly due to lack of inter coolers.

The benefits are non or low boosted takeoffs so a turbo, waste gate or induction pipe failure is not effectively an engine failure. The higher compression pistons are retained and the TBO is still 2000 hrs. Higher CHTs when boosted usually results in more cylinder head cracking.

They utilize an accessory scavenge pump and a separate turbo oil system filter. The exhaust pipes are robust but the wastegate actuating system is poorly designed.

The factory system that was available on the C and D is an electric actuated “on/off” system that is also turbo normalizing. They utilize a single larger turbo and work well but are very hard to source parts for. They have a different cowling design and have an additional pair of cowl flaps.

The factory optional E/F Airesearch system is boosted to achieve rated 250 HP with lower compression pistons. It utilizes a density controller, larger cowl flaps, 1200 series mags, and piston cooling oil spray jets. TBO is reduced to 1800.

They are typically reliable and have better parts availability. The induction air is taken from the front cowl inlets that are slightly enlarged instead of a separate lower inlet scoop.

The Turbo systems don’t seem to have blow out issues as everything is forward of the firewall and mounted to the engines so they move in unison. The normally aspirated aircraft have issues with the forward exhaust cross over burning the fiberglass nose bowls. None of the turbo models have that problem.

"TBO is reduced to 1800. "

For a factory turbo'd F model? Wow, that's news to me.

My understanding is/was a 2000 tbo. TIO540-C1A.

Mark

You are correct. The earlier TIO-540J4A5 in the C has a recommended 1800 hr TBO. I believe the CIA originally had an 1800 TBO and was later amended to 2000.

The factory optional E/F Airesearch system is boosted to achieve rated 250 HP with lower compression pistons. It utilizes a density controller, larger cowl flaps, 1200 series mags, and piston cooling oil spray jets.

They are typically reliable and have better parts availability. The induction air is taken from the front cowl inlets that are slightly enlarged instead of a separate lower inlet scoop.

Basically the waste gate is operated by an oil pressure actuator that is controlled in response to throttle setting, temperatures and pressures to maintain a constant power setting automatically during a climb or descent. It also limits the manifold pressure and is ground adjustable. The RAYJAY system this must be done manually every thousand feet or so and in the early C model factory system it is simply switched on during high altitude operations and off prior to or during descent. In that case the waste gate is controlled with an electric solenoid.

If anyone is interested I will be listing an over the top Turbo F soon for one of my customers. It is not the one with coffin door, RStol and nacelle tanks but it has fresh paint, avionics, engines, boot etc and it does have my carbon fiber quick cowls. (See first page or two of this thread for info on the cowls).

I flew a 1974 E model factory turbo(Air Research). On takeoff roll after an annual in FLL, I noticed an odor and power difference.. aborted, returned to maintenance. They had not securely reconnected the crossover, and it torched the nose bowl.
As you said, I never had a problem with heat there before.

Mark is that yours?!? I’d sell my Aztec for a turbine or a nicer Aztec that’s it.