When we ran the engine for the first time we noticed a distinct lack
 of boost. It did  not occur to us to take the turbo apart and check
 it. The turbine was missing blade area. This happens when a small
 foreign object goes through the turbine while it is rotating at
 100,000 RPM. Nothing new here as the  CW R3350 TC would do the same
 thing when an exhaust valve broke up.

 When you just look at the exducer everything looks OK. We checked the
 compression on the TTC engine and it appears to have full compression
 on all chambers so it did not happen after we had the engine. I am
 building a Maximite rotary engine compression checker to get a
 better handle on that.

 Apparently, some time during the development process, an iron apex
 seal failed and took out the turbine. It is easy to forget and not
 check the turbine when that happens.

 Subsequently Iannetti ceramic apex seals were installed and they are
 cannon prof. Mistral intentionally detonated the engine and the
 Iannetti's  failed to break. The same thing cannot be said about the
 stock seals.

 A new ball bearing Inconel turbo cartridge cost $2400 so small
 donations would be welcome.

 Paul Lamar 830 East Santa Maria Street Suite 303 Santa Paula
 California 63060

 Paul Lamar

 Paul, at the top of my 8000 RPM 3rd pull I indicate over 1000C egt
 but this just momentary compared to an aircraft's sustained climb out
 temps.  At those temps it doesn't take much FOD to destroy a turbine
 wheel.

 Do you have the dimensions of the wheels... looks roughly like a 82mm
 compressor and a 74mm turbine OD.

 You probably need just the cartridge.  See attached.

 Barry Bordes

 It is a GT42 ball bearing Here is a screen capture. It is the
 complete turbo.

 When they open I will check the price for just the cart.

 what is 1000 c in f?

 Paul Lamar

1000C = 1832F  Kinda hot in there. I guess that's why oil passes
through a turbo unit rather quickly.

Regads,
Steve Thompson

We are running menthol so it should be 300 F lower than what Barry
is seeing.

 Never the less I just added a EGT sensor fitting to the Inconel
exhaust manifold.

Burned out my drill press motor
when the 1/2 inch steel drill welded it self to the inconel exhaust
manifold :-(   No Joke!   You must use a solid carbide drill. Cost about
$50 US for a half inch size.

Paul Lamar


The Rotary Engine free News Letter. Powered by Linux. If you want off
the list PLEASE let me know and I will remove  you.  ACRE NL web
site. http://www.rotaryeng.net You Tube http://tinyurl.com/beqqxas
Copyright 1998-2016 All world wide rights reserved.