BeechTalk - BT

Username Protected · **Posted:** 26 Feb 2025, 10:03

there is a solution to the problem of 100 LL going away and the fact that 100LL is not available in much of the world.

that is an engine that runs on any available quality auto gasoline.
thus it can be flown any where in the world and will use regular un leaded, non ethanol gas

https://flyadept.co.za/engines/

it is a 120 deg v6 being flown in South Africia and will have a flying demonstration at Eaa Airventure this summer.

It will fit in existing aircraft and will have versions from 250- hp to turbocharged engines that will provide up to 450 HP

they are setting up to do manufacture in the US

it is available now as an experimental and they plan to get it certified. the problem is these efforts need tremendous amounts of $$$ to get to that stage.

Username Protected · **Posted:** 26 Feb 2025, 11:55

Username Protected wrote:

that is an engine that runs on any available quality auto gasoline.

Given that car gas has ethanol in it generally, I thought that caused issues with aircraft fuel systems that made it unsuitable as an aviation fuel.

If you require ethanol free fuel, then you haven't solved the fuel availability problem since that is rare to find generally.

In theory, a geared V6 should be a fine aircraft engine, but so far, in practice, it has not turned out that way.

Mike C.

Username Protected · **Posted:** 26 Feb 2025, 14:49

Yeah ethanol free is hard to find and not a good solution. And I cant imagine E10 is good for aircraft.

I think diesel engines are the best to take over the prop piston market. or TP's that run on diesel.

Mike

Username Protected · **Posted:** 26 Feb 2025, 17:15

Username Protected wrote:

really interesting video visit of TurboTech

They seem to be developing a 250hp and 400hp class turbine

https://www.youtube.com/watch?v=FS21dsj_iG4

It would be great if they can hit 250HP....I thought they were still targeting the 140-150hp range.

Username Protected · **Posted:** 26 Feb 2025, 17:44

Username Protected wrote:

Yeah ethanol free is hard to find and not a good solution.

I have scoped out where to get it as I buy a fair bit of it. I drive 12 miles to the airport and on that trip, I pass 7 filling stations offering ethanol-free mogas. One of them 91AKI (where I get my corvette fuel) and the others 87AKI (Beechcraft, Cub, and Farmall fuel)

Username Protected · **Posted:** 26 Feb 2025, 19:33

over seas high octane non ethanol is generally available everywhere and in some states where it is not sold at the pump it is available as Boat Gas and for some offroad uses.

Username Protected · **Posted:** 26 Feb 2025, 20:19

Username Protected wrote:

Yeah ethanol free is hard to find and not a good solution. And I cant imagine E10 is good for aircraft.

I think diesel engines are the best to take over the prop piston market. or TP's that run on diesel.

Mike

The problem with TP's that run on diesel is that you run into low temperature/high viscosity/freeze point limits. We did certify a few models to use Arctic Diesel, which still had warmer limits than JET A, and has limited availability. The engine has to be certified to use it also, and things like sulfur content may make a difference.

Username Protected · **Posted:** 01 Mar 2025, 20:38

Username Protected wrote:

really interesting video visit of TurboTech

They seem to be developing a 250hp and 400hp class turbine

https://www.youtube.com/watch?v=FS21dsj_iG4

It would be great if they can hit 250HP....I thought they were still targeting the 140-150hp range.

Username Protected · **Posted:** 31 Mar 2025, 02:00

As long as we are also discussing diesels, how about a two stroke turbocompound diesel like the Napier Nomad?

In for a penny, in for a pound as the British used to say.

Username Protected · **Posted:** 02 May 2025, 02:01

Username Protected wrote:

I certainly want to see innovation, and the rolls Royce M250-B17F/2 is a 200 lb turbine Turbo prop that burns 25 gph for flight planning purposes (about 22 in cruise) (in the p210n silver eagle) ... has 450-500Hp takeoff power (at sea level) and 380hp continuous... it is sensitive to temperature and altitude.... but still falls squarely in the performance envelope of the 15-21k’ flight levels for GA... and for those who want higher and faster, there are variants that go to 650hp.. so they could be flat rated to higher critical altitudes..

Rolls even has a FADEC module for the m250 series...

It is used in the silver eagle conversion and a bonanza a36 conversion, soloy 206 conversion.. and a few other fixed wing planes...

Now the problem is it is very expensive... a new one lists around $700k?

I don’t know how to get that price down or why it is that expensive... is it a function of cost of production? Monopoly? Scale of sheer number (or lack thereof)?

If someone committed to converting 1000 airplanes would the cost be radically different? I don’t know..., but there already is an engine in existence since the 1950’s that is suited to the job..

Rolls had a new model RR500 version, specifically designed for GA that they were going to make that they shelved in 2012.. flat rated to 325hp at 15K’

https://youtu.be/j2nD7Nqh7B4

I don’t know why, perhaps the price tag and the fact that there are virtually zero
Pressurized ga aircraft currently made (except the piper M class and they are dedicated to the pt6)...

Boggles my mind that cirrus and diamond are not pressurized... even 3psi would be a game changer for those aircraft...and open up the world of turbine potential to them...

I mean who really wants an engine that is designed for 15-20’ and have to wear O2 all the time... not me...

We had a testbed P210 with that engine that was called the 250. Besides costs, the other disadvantage was that it really needed more pressure differential. It was zippy down low, but no faster than a P210R up in the 20's.

Username Protected · **Posted:** 02 May 2025, 08:31

Username Protected wrote:

We had a testbed P210 with that engine that was called the 250. Besides costs, the other disadvantage was that it really needed more pressure differential. It was zippy down low, but no faster than a P210R up in the 20's.

i'd still take it. more reliable, less vibration, lower failure rates, faster climb, no temperature problems, simpler operation, fewer moving parts, etc.

all good things

Username Protected · **Posted:** 02 May 2025, 09:48

I have a 1970s RR250 B17C in my 206. custom conversion.

It works great. temps out a little low, super easy to operate. accepts up to 50% AV Gas if you're ever in a pinch.

Components are awfully expensive tho...

Soloy uses freshies and the cost is insane. it's too bad it wasn't at an affordable price point, wed see a lot more conversions.

Username Protected · **Posted:** 01 Jun 2025, 23:44

Username Protected wrote:

This is a very interesting thread and I'm way late to the discussion. I just wanted to add one thing.

If a plane with an IO-550 is producing 250hp @ 15k and a RR250 is producing the same HP at 15k, the RR250 plane will still cruise faster than the piston plane by a decent amount. The reason being is that the drag caused by the much bulkier nose of the IO-550 plane will be quite large in comparison to the RR250 plane.

All of my numbers are hypothetical of course. Just making a point.

It is no really the much bulkier nose that has the biggest effect; it is the cooling drag.

Username Protected · **Posted:** 02 Jun 2025, 15:36

Username Protected wrote:

We had a testbed P210 with that engine that was called the 250. Besides costs, the other disadvantage was that it really needed more pressure differential. It was zippy down low, but no faster than a P210R up in the 20's.

i'd still take it. more reliable, less vibration, lower failure rates, faster climb, no temperature problems, simpler operation, fewer moving parts, etc.

all good things

Username Protected · **Posted:** 02 Jun 2025, 17:28

Username Protected wrote:

I agree with what you said, but when there is a failure, it can cost an arm and a leg.

But they happen FAR less often.

The piston pilot contemplating turbines gets scared because they multiple piston failure rates times turbine repair costs. It just doesn't work that way.

Significant unscheduled turbine engine maintenance is pretty rare. It happens, but these engines go for very long periods of time without needing hardly anything.

The routine and unscheduled maintenance of a piston engine adds up to a lot of money over time, even more so when you think about in terms of cost per mile.

Mike C.

Low cost turbine....