Mailing List flyrotary@lancaironline.net Message #57358
From: Patrick <patrick@hoffmann1.net>
Subject: Re: [FlyRotary] Re: Top 7 reasons for using an auto conversion
Date: Mon, 23 Jan 2012 12:15:36 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
If it's more reliable and cheaper, double bonus. If it's just cheaper, I start getting scared.

Imagine the conversation with your spouse if the airplane suddenly becomes a glider: "But Honey, I saved a bunch of money by switching to cheap parts...."
Can't see that ending well.

John Slade's descriptive narration of the failures of several turbos that he used _because_ they were cheap is an excellent example. In the end, the correct part was more reliable and ultimately cheaper than the cost of buying three "cheap" turbos and the resulting engine overhaul.
BTW: Thank You, John, for your website.  I learned a lot and appreciate your candor.  It will save lives, money, and time for others if they learn from you.

Patrick H


Dale_R wrote:
On 1/22/2012 5:02 PM, Thomas Mann wrote:
When the majority of the reasons are "Cost" related, I get a little nervous.

My reasons for going with the rotary:

Less complexity (the typical pistons, valves, pushrod, etc. argument) which equates to Greater Reliability

Sorry to play "Devil's Advocate", but I have to agree with Al W on part of this.

The jump from "simplicity of fewer components" to "increased reliability" is partially an illusion.  The reliability that needs to be compared is system-to-system, not system-to-component.  As Ernest C. pointed out, the most likely way to get an inexpensive AND reliable "auto conversion" is to copy another successful (i.e. flying) installation.  Do ~anything~ differently will likely result in more expense (fixing what didn't work out) and reduced reliability during the development phase.

> Less Oil Burn : if you told me I was going to have to put a quart of oil in every 8-10 hours of operations for a car I would say you are crazy.

> TBO - 50,000 miles is about 1000 hrs of operations. I have 90,000 on my Safari and it's going to go well beyond the 2000 hrs that I would get out of a Lycoming.

> Back to cost - I'm not trying to save money by going with a rotary. I plan on top-notch parts, (i.e. ceramic seals, etc.) and having the engine balanced.

> As far as Auto- Conversions, I'm not on board if it has pistons.
> Again, my motivation is the simplicity of a rotary, not cheap.

I may be foolish - especially considering my current financial situation (certainly, most of my Canard associates think so) - but I'm in agreement with those who are willing to spend the extra sweat-equity to help advance the knowledge base for the rotary - so that, a few years down the road, some new builder will be able to put together a package of components for a rotary installation (in a canard) with full confidence that it will outperform a Lycosaurus installation in every way.


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