Mailing List flyrotary@lancaironline.net Message #50441
From: John Slade <jslade@canardaviation.com>
Subject: Re: [FlyRotary] Re: Turbo Considerations....careful, its long
Date: Wed, 17 Mar 2010 23:18:22 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
I don't know which Dave this is, but the argument presented seems heavily biased and emotive. Let me try to add some perspective....

>turbo's develop LOTS of heat...
Yes, they get hot, and yes, you need an inter-cooler, plumbing and a pop-off valve. The total installed weight with these items is still about 40# less than a 20B, and the weight is further forward (for a pusher).

>make this chunk of iron glow red hot, to the point its right on the limit of sagging/melting into failure
Yes, they can glow red. They're built to withstand the heat. A large percentage of automobiles, a majority of trucks and thousands of aircraft use turbos every day. The technology is proven over many years and millions of miles. Every turbo vehicle I've ever owned just "went faster". The turbo never needed any maintenance and nothing ever melted. As I've also proved, that doesn't mean they can't fail, especially if used outside their design environment. The trick is to do it right first time with the right equipment for the job, and the plumbing and shielding that's needed to make it reliable.

>It needs LOTS of oil, LOTS of insulation, LOTS of intercooling
Yes, it needs an oil supply (plus a coolant supply), a standard auto turbo shield and an intercooler. Provide these and all is well.

>If something can "see" the glowing red hot turbo housing or manifold, expect it to be damaged by radiant heat...
Thats why they all have a stainless steel and fiber-frax shield standard.

>but MUCH LESS complexity, several less genuine failure points, and a much more forgiving installation.
There's SOME truth in this, but four extra coils and injectors plus the wiring for them add they're own failure points and complexity.

In truth there are pros and cons to both approaches. There are also good things to be said about Subaru engines, with or without turbos. All can be made to work reliably and safely.

Just trying to aim the discussion in a more reasonable direction.....
Regards,
John

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