The EVOT-550 with the -21 engine is an interesting option. This is something that some build shops have been recommending for years as an alternative to the piston. The -21 engine is what they pull off of King Airs to put on the -135 so used ones are readily available. Below is a spreadsheet I got years ago from one such shop. Since the Lycoming is so expensive and has to be new while the -21 can be had used and cheap, the build cost difference goes away. Add in cheaper fuel and longer TBO and it makes a pretty strong alternative to the piston. But I think only one or two planes were actually built with the -21, which is what makes it interesting. By making the -21 a factory supported option it seems like EAC is producing a very strong alternative to their own piston version in pursuit of a market that, when offered by build shops, has been shown to be quite small.

Has anyone looked at putting a Garrett -10 on the front of the Evolution?

Web research this morning says the -140 is the latest and most powerful of the "small" PT6, with a single stage power turbine vs. the two-stage power turbine in "medium" engines like your -42. They improved the compressor with more CFD-designed airfoils and a blisk for one of the axial compressor stages. The torque limit (gearbox) is 867 hp. but thermodynamically it's a 1075 hp. motor. Its only applications to date have been the current Caravan, upgrades to older Caravans and ag planes. Blackhawk offers both -42 and -140 Caravan upgrades but not for much longer, I would think, as the -140 upgrade is more powerful and cheaper, requiring little or no mods to cowling and engine mount. The -140 also is designed for lower operating costs, 5% better SFC than "comparable" engines (whatever that means) and much higher cycle limits so even the ag and skydiver markets doing short flights won't cycle out before timing out.

Besides the lower lifecycle costs, the pitch for ag operators is better hot/high performance. The -140 will of course lose power with altitude but as a percentage of the 1075 hp. thermodynamic rating, not the 867 hp. gearbox limit. I should think it would have more power available than a -42 at any altitude. And of course it is a more modern engine.

Actually a used -21 is quite expensive vs a used -28. Don't ask why because I don't know for sure. Something about the parts from the -21 is shared with something else... I don't remember. A -28 is essentially a -21 but has a stronger gear box allowing higher takeoff power. At altitude they'd perform very similar. I think a used -28 can be bought for at or under $100k. Unless pricing has changed since I looked last.

Not that I'm aware of. You'd need someone to design an entirely new cowl, engine mount, etc.

If I were to look into doing something other than a PT6, it would be the new GE with the improved power and lower fuel specifics (supposedly). Anyone know much about those motors yet?

How many hours would a typical -28 have on it at that price? Also, is the overhaul cost similar to other PT6 variants when that time comes?

How many hours would a typical -28 have on it at that price? Also, is the overhaul cost similar to other PT6 variants when that time comes?

Gerry.- Interesting information.

I am reading that the 140 AG is for the new Airtractor AT502XP
http://www.marketwired.com/press-releas ... 080337.htm

I believe the same firewall that is used on the 135A can be used in the 140AG Engine and their standard FW can accomodate to this engine. It probably is a way of P&W supporting Evolution Aircraft Company to sell their new engines. We shall see if it gives the same power as a -42A designed for high altitude since Air Tractors fly low and need a lot of HP. It is good Lancair is finally offering many engine solutions for their Kits.
If they would sell the Kit without avionics and a builder can install a cheap -28 / -21 it be a great hit bang for the buck on performance with the Garmin 3X. A
Its a mistake they did not get into terms the "!·$%* from Aerotek. There are a bunch of -42 engines from Black Hawk Conversions and old KA200´s that could be bought at a great price- Put into a program similar to MORE and have a fantastic super efficient supported Product.

What I would change on the EVO:

-Rardar Pod and Proven Stormscope / Strikfinder.* (Don´t work con Composite AC).
- Auto Switch Tanks. * Like a TBM
- More Robust and Lighter Landing Gear. * The original prototype had Aluminum Main LG but it proved to be not as robust so they designed a steel one that is obviously more heavy- So I Titanium Main Landing gear would be awesome. (Pipistrel on the Panthera uses Titanium). Would be absolutely much lighter=faster
- Steerable & more robust Nose Strut. Lancair on the Standard Kits, -42 applicatons and non Up-graded Kits used the same derivative as the one used on the IV´s with redesigned attach points. When you add fuel + load on an Evo it is a much heavier aircraft. This has been the weak point of all Evo´s causing Nose gear collapse´s from badly designed system & delicate nose strut that cannot be towed by the typical FBO. Any damage can cause nose shimmy and nose gear collapse!!

The -42 is rated at 850hp but the thermodynamic hp rating is 1130 if I remember correctly, so the -42 should be better at altitude. If anything they'd be similar. I'd be interested to see how much fuel the AG140 burns at altitude.

This site says similar, roughly 10% higher for the -28 than the -21, doesn't say why.
http://blog.overhaulbids.com/pratt-whit ... haul-cost/

Looks like a great engine but bigger, competing with the large frame PT6 in the Pilatus et al. GE's competitor for small frame PT6 applications seems to be the H80, the updated Walther, not very interesting.

What does the -28 burn per hour?

About 35gph at FL250

I agree with most of this. I wouldn't want the Radar pod. I'd rather fly around weather than through it. Pod would decrease speed by about 10-15 kts. Going around doesn't add that much time with the speed of these planes.

I agree 100% on needing a more robust landing gear. Nose gear in particular. I don't like not having a link to my pedals. Lots of planes have the free camber setup, but it's not something I really like.

A radar pod for the Evo is in development. Pics from the factory.