Message-ID: <38FDBEB4.7CCB242D@regandesigns.com>
Date: Wed, 19 Apr 2000 09:12:05 -0500
From: Brent Regan <brent@regandesigns.com>
To: colwell@innercite.com, Lancair List <lancair.list@olsusa.com>
Subject: Re: Cont. vs Lyc. etc.
References: <38F5CD11.F791623@regandesigns.com> <38FD3CE5.638431F1@innercite.com>
Mime-Version: 1.0

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Steve & Claudette Colwell wrote:

> Brent, you used a Lyc. instead of Cont. at considerable additional time and
> expense.  If you would share your reasoning it would be of interest to me
> (L2K on order with a factory approved TI0-360, O-540 or I0-550 engine option
> I understand) as well as the group.

Hi Steve:

My reasons for selecting The Lycoming TIO-540 over the TSIO -550 were/are:

Lycoming has a LOT more experience in the 350 Hp range than Continental. One of
the staples of the piston twins is the TIO540-J2B.

The Lycoming also has a larger diameter crank.

I didn't trust a factory engine from either so the ability to buy a used core
was a factor. Lots of Lyc 540 cores out there, many cheaper than 360s.

The Continental 550 is really a bored 520 running at higher RPM. The college
boys that decided this was a good idea had no insight into the design tradeoffs
that the original designers made. The original designers all being dead of old
age, of course.

The Continental "Tuned induction" is a joke (excuse me, I meant to say
"sub-optimal"). Splitting flow with a fork does not produce a balanced
distribution. This is one of the reasons the Gami injectors seem to work well on
the Continentals, to compensate for poor air distribution.

VIrtually all the "engine abusing" aerobatic pilots use Lycomings.

Mechanics prefer you buy a  Continental (more money for them).

OK, so now that I have pissed off every Continental owner out there, I might as
well finish. IMHO most pilots who fly behind auto conversions have a death wish.
Auto engines are not designed to produce rated horsepower continuously (if they
can at all). Auto engines spend 95% of their life at <25% rated output. To
properly re-engineer an auto engine for aircraft takes a LOT of time, money and
testing. The few efforts that have been successful, like Jim Rahm's Enginair and
the Eagle (we hope), are testament to this.

Another myth is that electronic controls are the answer to reliability and
economy. I fail to see how adding complexity to a system increases it's
reliability. As far as economy goes, most automotive electronics is tasked with
reducing emissions in fringe operating conditions (cold start, hot start, full
throttle...).  Aircraft engines only have three operating points, taxi, climb
and cruise. Most of the talents of an automotive engine management system would
go unused on an airplane engine but the complexity and potential failures
remain.

There IS one good reason to implement electronic controls in  an aircraft
engine, to take the pilot out of the loop. My idea of the perfect engine
management and control system would have one lever, a display and a light. The
lever would control thrust, the display would display percentage thrust produced
and the light would have three states; off for "all OK", on for "Land Soon", and
flashing for "Land Now". In the event of an engine failure a large "Flag" would
appear in the forward visual display indicating that the engine had stopped
turning and the prop had feathered.

If GA is to be a valuable part of the nation's economy 50 years from now then it
needs an efficient engine that runs on Jet-A. The best candidate to date is a
liquid cooled diesel. Now if we can only find someone with $20M to build us one.

Regards
Brent Regan


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