I second Brent's well considered concerns.

Take a look at the inside of a  2008, 2009, 2010  Cirrus  Turbo for examples of:

1) Effective fiber glass cowl protection with simple reflective tape material on the inside (cowl stays cool to touch after shutdown near turbo).

2) General internal protection from infra-red from exhaust plumbing from heat shields that still allow proper cooling of exhaust plumbing and the turbo housing.

Brent is right.  Conformal heat shields on turbo hot sections are an invitation to coke the oil on the turbo bearings after shut down. Regards,  George  -----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Brent Regan
Sent: Monday, March 01, 2010 11:37 AM
To: lml@lancaironline.net
Subject: [LML] Re: IV-P Turbo Blanket

I don't like the idea of insulating a turbocharger turbine housing as it necessarily restricts heat flow from the housing both during operation and after shut down. The Continentals have an alarmingly high maximum TIT of 1650 degrees F, necessitating the use of Inconel for the exhaust plumbing. Heat is supplied to the turbo via the exhaust gas. Heat is rejected via the exhaust gas, engine oil, conduction to the bearings and compressor and radiative cooling. Radiative cooling climbs exponentially with temperature. Blocking the flow of radiated heat causes the heat to go elsewhere, requiring that the bearings, compressor and discharge oil are all incrementally hotter.

After shut down, connective air currents quickly cool the turbine housing. Keeping it warm in a blanket means the heat has more time to work on breaking down the oil in the bearings.

Finally, what about the headers? If the logic is that the source of the radiative heat has to be blocked to prevent having to insulate the cowling then the headers and crossover must also be insulated as they are exposed to the same hot gasses and their area is substantially greater than the turbine housings.

The best answer is to not insulate the turbos and to add a reflective shield to the lower cowling such as Zetex A600 plus (see attached picture). This addresses the heat from all sources without focusing it to sensitive areas.

Automotive, commercial, marine and truck turbos operate at lower TITs, and diesels are much much lower. What works in one industry may not work in aircraft applications.

Regards
Brent Regan