lml@lancaironline.net Mailing List Archive

<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 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? _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com.