From: "Ron Laughlin" <ronlaughlin@hotmail.com>
To: Klusmanp@aol.com, lancair.list@olsusa.com
Bcc: 
Subject: Re: Legacy Engine choices
Date: Mon, 04 Jun 2001 00:51:26 -0500
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Reply-To: lancair.list@olsusa.com

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Paul, As you have stated, there doesn't seem to be much difference in price 
between the IO-360 and IO-540 on the used market. As I see it, the major 
consideration then becomes performance. Carsten tells me that there is room 
enough for a turbo under the cowl of his IO-540 Legacy. So... between the 
IO-360 and the IO-540, I would use the IO-540. Maximum cruise horsepower on 
a turbo normalized stock IO-360 is only going to be about 150hp (75%) at any 
altitude. The normally aspirated IO-540 will produce more than 150hp all the 
way up to about 14K msl. I can't see any reason to seriously consider the 
IO-360, except that it is lighter than the IO-540 and has 2 fewer cylinders 
to maintain.


A turbo adds complexity (another point of possible failure), additional 
weight and it radiates a lot of heat under the cowl. Please don't 
mis-understand. I like turbocharged airplane that I currently fly. I like to 
fly in the mid-teens on long cross counties. The air up there is usually 
smooth, the traffic is thin, the fuel economy is good and much of the 
weather is below you. I also like not having to worry about density altitude 
in the summer and/or in the high country. However, I've been lucky (I'm 
told) and haven't had to replace or repair my turbo....so far. They can be 
expensive little items when they need attention.

After talking to a certain test pilot (who shall remain nameless <G>), I 
have decided to go with the Cont IO-550. I can get 50 extra horsepower and a 
brand new engine for the price of a rebuilt Lyc IO-540. It will give me 
232hp at 75%, 200hp at 65% and 170hp at 55% without the additional 
complications and possible problems of a turbo. I should be able to get 
170hp (55%) up to about 15K msl. A normally aspirated IO-540 will only be 
giving me about 143hp at 15K msl. A turbo normalized IO-540 would put out 
about 195hp at 15K (and on up) so it's going to do better than a non-turbo 
IO-550 at about any altitude above about 12K. I personally don't like going 
higher than 18K without cabin pressurization, so the performance offered by 
the IO-550 meets my needs.

I also like the idea that it may be possible to run the IO-550 lean of peak. 
The same test pilot mentioned above tells me he has seen 230kt TAS at 5gph 
on in the factory Legacy. 5gph is a little hard for me to believe but he 
stands by his claim. Non the less, range frequently becomes more of a factor 
than absolute TAS on long cross-country flights.

The Lycoming VS Continental debate has been beat to death on most aviation 
related web lists already. I realy have no interest in stirring the "brand 
loyalty" pot again. I'm just trying to figure out which of the above engines 
gives me the best performance numbers for the least amount of money and 
headaches. There is a great deal of disagreement about this subject, even 
among the staff members at Lancair! I have been impressed with the vast 
amount of knowledge and experience that I have seen on this list in past 
discussions of such matters. Any additional suggestions or pros and cons 
would be appreciated.

Ron Laughlin
Legacy 0.001%
SNIP
>What are your thoughts on a turbo IO360 Lycoming vs non-turbo IO540 
>Lycoming?
>I've noticed, as you have, that the used IO540s are not more expensive than
>the used IO360s. I'm wondering if the extra weight and complexity of turbo
>makes the IO540 the better choice.
>
>What do you think?

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