350HP Mooney

[Raptor05121]

Screw 8 cylinders. Just get a turbine. There is a Luscombe 8F flying around with a miniature APU on the nose. No reason we can't do the same. Much smoother, too.

[jetdriven]

2 minutes ago, Raptor05121 said:

Screw 8 cylinders. Just get a turbine. There is a Luscombe 8F flying around with a miniature APU on the nose. No reason we can't do the same. Much smoother, too.

A 350 hp turboshft would burn something like 40 GPH. 1.5 hours range.  Not practical. 

[Raptor05121]

A quick google search has a Air Tractor owner claiming he has a PT-6-15 at 680 SHP and it burns 47 GPH. Soloy has the 450hp Rolls Royce turbine on a Cessna 206 burning 17gph @ 146kts and 25gph @ 185kts with stock 87 gallon tanks.

I'm sure we could get lower specific fuel consumption and higher speeds with our slippery airframes. Knock another 200lbs off the airframe as well.
 

[INA201]

I'm surprised no one has strapped a turbine on a Mooney.  

[aviatoreb]

So we know this is just a for fun what-if discussion since I doubt anyone is going to hang a IO720 on the nose of a Mooney.  But it is a fun idea.   I like the idea of a turbine better since it sounds cool when you turn it on!  But the fuel specifics are not good.

But this one is for real a good idea if it really gets off the ground - vaporware engines - but with real big boys like Dick Rutan in the effort

The eps grayflight v8 diesel,

https://eps.aero/the-eps-engine/the-eps-advantage/

300hp is a cruise setting at 14gph.   compacted graphite is stronger than aluminum, and it has a 3000hr tbo (projected) and it is roughly weight comparable to a big bore 6.

305hp is my airplane's take off power, so yes I have tried out to see what it will do at that for like 60 seconds in level flight...the thing moves.  I can't imagine having that kind of power for cruise at such a modest fuel burn.

That is the engine I want....I filled out the STC "me too" sign in.  https://eps.aero/is-your-aircraft-an-stc-candidate/

everyone else too please....

Edited November 8, 2017 by aviatoreb

[AH-1 Cobra Pilot]

1 hour ago, aviatoreb said:

The eps grayflight v8 diesel, 300hp is a cruise setting at 14gph. 

They are probably exaggerating a little.  That yields a SFC of 0.28 or 0.327 lb/hp/hr, (depends on your presumed fuel density).  A good Caterpillar diesel gets about 0.34 @ 1050 rpm.  https://s7d2.scene7.com/is/content/Caterpillar/LEHW0058-00

If you are truly interested in higher powered engines, I have a rotary engine patent, and I even wrote my Masters Thesis on its analysis.  A 127 cu in engine turning 2700 rpm should produce 380 hp @ 2.4 gph.  If you have $2,000,000 to invest, (I guarantee a return between 0 and 50,000%), please PM me.

[aviatoreb]

5 minutes ago, Ah-1 Cobra Pilot said:

They are probably exaggerating a little.  That yields a SFC of 0.28 or 0.327 lb/hp/hr, (depends on your presumed fuel density).  A good Caterpillar diesel gets about 0.34 @ 1050 rpm.  https://s7d2.scene7.com/is/content/Caterpillar/LEHW0058-00

If you are truly interested in higher powered engines, I have a rotary engine patent, and I even wrote my Masters Thesis on its analysis.  A 127 cu in engine turning 2700 rpm should produce 380 hp @ 2.4 gph.  If you have $2,000,000 to invest, (I guarantee a return between 0 and 50,000%), please PM me.

Hmmm - I would love to help, but I am $1,999,994.99 short.

I love rotary engines - I bought a 1979 maza rx7 just because I loved the engine when I was in college.

Yah sure I bet those guys are exaggerating - but meh - Ill take one.

[Greg Ellis]

22 hours ago, LANCECASPER said:

 

The liquid cooled idea is great - that's the Voyager engine that RAM uses on twin Cessna upgrades (http://www.ramaircraft.com/Aircraft-Engine-Upgrade-Packages/Performance/414A-Series-V-Performance/SM044C4-414A-Series-V-Performance.htm). The problem with it in a Mooney is I don't know who you would take it to that has any experience with it for a Mooney annual. Maybe Lasar, Ton Gun or Maxwell and possibly Dugosh - but I don't know for a fact that any of those shops will work on one. Someone told me a couple years ago that there's only one shop in the country that will accept one - not sure which of the four shops it was. Any even if they do, how proficient are they on them if they hardly ever see them? There might be 1 - 3 flying. It would be nice if Mooney would test that engine for a next generation Acclaim replacement - there are a lot of advantages. I just think in its' present state it's destined to be an orphan.

I think Don Maxwell has worked on this airplane.  I bought my C model 11 years ago and I was out at Don's back then and I think I remember seeing this very airplane there (the color seems familiar).  At the time I was curious, being a new Mooney owner and having no knowledge at all about the many different models, as to what the big ports were for exiting the empennage and I remember asking Don about them.

[Raptor05121]

45 minutes ago, Ah-1 Cobra Pilot said:

They are probably exaggerating a little.  That yields a SFC of 0.28 or 0.327 lb/hp/hr, (depends on your presumed fuel density).  A good Caterpillar diesel gets about 0.34 @ 1050 rpm.  https://s7d2.scene7.com/is/content/Caterpillar/LEHW0058-00

If you are truly interested in higher powered engines, I have a rotary engine patent, and I even wrote my Masters Thesis on its analysis.  A 127 cu in engine turning 2700 rpm should produce 380 hp @ 2.4 gph.  If you have $2,000,000 to invest, (I guarantee a return between 0 and 50,000%), please PM me.

I've always been a fan of Mazda. Just curious if you highlighted on the apex seal, either an improvement or adaptation to its design?

[carusoam]

@Ah-1 Cobra Pilot want to have an audience for your project?

We have had at least one grad post their thesis on MS.

You won't get a better, more concentrated, interested audience.  Pilots, mechanics, professors, scientists, motorheads and engineers...

How does your theoretical engine release so much energy from a gallon of fuel?

There are a few nice attributes of using diesel...

• higher density... more fuel fits in the same tank...
• higher energy density... more power per pound of fuel...
• better economics before it gets to the plane compared to 100LL... no Pb

Consider posting what you wrote...

Best regards,

-a-

[jetdriven]

4 hours ago, Raptor05121 said:

A quick google search has a Air Tractor owner claiming he has a PT-6-15 at 680 SHP and it burns 47 GPH. Soloy has the 450hp Rolls Royce turbine on a Cessna 206 burning 17gph @ 146kts and 25gph @ 185kts with stock 87 gallon tanks.

I'm sure we could get lower specific fuel consumption and higher speeds with our slippery airframes. Knock another 200lbs off the airframe as well.
 

The sfc of the engine wont change depending on the airframe. It may burn 23-25 GPH at 25,000' but you have to climb there first. And the FF of a turbine isnt much less than cruise on the ground, and 2-3X cruise FF in climb. SO the first hour you might burn off 44-47 gallons. then 25 per hour thereafter. But still, its not even close to a piston engine in economy.

[AH-1 Cobra Pilot]

2 hours ago, Raptor05121 said:

I've always been a fan of Mazda. Just curious if you highlighted on the apex seal, either an improvement or adaptation to its design?

No, nothing like the Wankel.  I use separate compression and combustion epicycloidal chambers with a sliding vane in each.

[AH-1 Cobra Pilot]

2 hours ago, carusoam said:

@Ah-1 Cobra PilotHow does your theoretical engine release so much energy from a gallon of fuel?

There are a few nice attributes of using diesel...

• higher density... more fuel fits in the same tank...
• higher energy density... more power per pound of fuel...
• better economics before it gets to the plane compared to 100LL... no Pb

I use 37:1 compression ratio, so better thermal efficiency.  Then, I have a long expansion stroke, and very little reciprocating mass.

Gasoline actually has a higher energy density than diesel.  20260 BTU/lbm vs. 19110 BTU /lbm.  Diesel has more energy/gallon, though, 138110 vs. 116485 BTU.

[Jerry 5TJ]

7 hours ago, jetdriven said:

A 350 hp turboshft would burn something like 40 GPH. 1.5 hours range.  Not practical. 

Well, close:  the PT6A-35 in my P46T at FL270 delivers around 320 shaft hp (750 ft lbs torque) in cruise.  That's at about 700 degrees ITT and 96% Ng. It's burning 29-31 GPH at ISA+10. 

That's about the same fuel flow as a 310 hp Ovation 3 at full throttle, come to think of it.   

 

 

 

[Igor_U]

20 hours ago, aviatoreb said:

Could you modify a Mooney long body to cary an IO720?  Include a super charger.  If a mooney could do 225 at 10k and 270 at 25k....we would have a MAJOR rebound.

Someone needs to run the W&B for such a thing - could it be made to work theoretically?

Problem is it would require also the gussets work like on the Mooney rocket 351 liquid to stiffen the airframe.

225 at 10k would be quite a thing and it would really sell airplanes.

Yes,

Those would be great performance numbers, however there are laws of physics against you.

 

At 10,000 ft, my F model (, MTOW, with 201 mods) cruses 150KIAS using 135HP (~9gph LOP).

 

Assuming same weight (min fuel), same prop efficiency, same trim and cooling/cowling drag (highly unlikely with big engine), etc, you will need 3.375x more power which is 455.6 HP to fly 1.5x faster = 225kt. Horsepower is proportional to Velocity cube.

Using same assumptions, this 350HP engine would give you 206 KTAS max speed at 10k. Of course, real plane would be heavier, more drag etc...

 

I’m afraid to think about fuel flows in both cases (ROP)!

 

There are quite a few design challenges of putting a big motors on a plane designed for small one, W&B, wing loading (Stall speed), range due to reduced useful load etc..

 

I would still love to hear from @Chessieretriever regarding a performance of Liquid Rocket.

It’s a cool plane but there’s a reason why only few were built.  

 

Regards.

[Guest]

8 hours ago, Raptor05121 said:

A quick google search has a Air Tractor owner claiming he has a PT-6-15 at 680 SHP and it burns 47 GPH. Soloy has the 450hp Rolls Royce turbine on a Cessna 206 burning 17gph @ 146kts and 25gph @ 185kts with stock 87 gallon tanks.

I'm sure we could get lower specific fuel consumption and higher speeds with our slippery airframes. Knock another 200lbs off the airframe as well.
 

I doubt it’s making 450HP if it’s only burning 17GPH.

Clarence

[aviatoreb]

3 hours ago, Igor_U said:

Yes,

Those would be great performance numbers, however there are laws of physics against you.

 

At 10,000 ft, my F model (, MTOW, with 201 mods) cruses 150KIAS using 135HP (~9gph LOP).

 

Assuming same weight (min fuel), same prop efficiency, same trim and cooling/cowling drag (highly unlikely with big engine), etc, you will need 3.375x more power which is 455.6 HP to fly 1.5x faster = 225kt. Horsepower is proportional to Velocity cube.

Using same assumptions, this 350HP engine would give you 206 KTAS max speed at 10k. Of course, real plane would be heavier, more drag etc...

 

I’m afraid to think about fuel flows in both cases (ROP)!

 

There are quite a few design challenges of putting a big motors on a plane designed for small one, W&B, wing loading (Stall speed), range due to reduced useful load etc..

 

I would still love to hear from @Chessieretriever regarding a performance of Liquid Rocket.

It’s a cool plane but there’s a reason why only few were built.  

 

Regards.

...I think the latest Mooney's are quite a bit sleeker, aren't they?

I just made those numbers up off the top of my head as a quick guesstimate.  Comparing to the Acclaim/ovation performance.

So Ovation on 75% of 280hp (210hp) claims a 191tas cruise.  So imagine what the same airframe would do on 300hp as 75% of 400hp?  SO I guessed 225 by the cube rule, we get 342hp would be required....which is do-able with a io720.  But Looks more like 215tas is more realistic - assuming all is the same.  Now I bet the ovation does that at 8000ft?  So at 10k, if turbo charged - I bet 220....

OK - so I lower my guess from 270 to 265 at max speed at top altitude - keeping in mind that the acclaim claims 243.  SO ....330hp gives 260 and that is within the realm of a cruise power for a turbo charged io720.

[aviatoreb]

3 hours ago, Jerry 5TJ said:

Well, close:  the PT6A-35 in my P46T at FL270 delivers around 320 shaft hp (750 ft lbs torque) in cruise.  That's at about 700 degrees ITT and 96% Ng. It's burning 29-31 GPH at ISA+10. 

That's about the same fuel flow as a 310 hp Ovation 3 at full throttle, come to think of it.   

 

 

 

...that would look nice on the nose of ,my airplane - so yeah - let me guesstimate again - 30gph and 270tas with a pt6-35 mooney.

[ragedracer1977]

23 hours ago, Raptor05121 said:

Screw 8 cylinders. Just get a turbine. There is a Luscombe 8F flying around with a miniature APU on the nose. No reason we can't do the same. Much smoother, too.

I used to park right next to it at DVT.  It's been sitting idle for a long time.

 

 

[aviatoreb]

2 minutes ago, ragedracer1977 said:

I used to park right next to it at DVT.  It's been sitting idle for a long time.

 

 

Hah! Now that's what Im talking about....

Love the sound of a turbine spooling up.

What the heck is the purpose of that?!  A turbine on that lil ol thing?  What is it?

[MIm20c]

1 minute ago, ragedracer1977 said:

It's been sitting idle for a long time.

I’m sure the owner wouldn’t miss the fwf if we used it for some testing.  

[ragedracer1977]

Just now, aviatoreb said:

Hah! Now that's what Im talking about....

Love the sound of a turbine spooling up.

What the heck is the purpose of that?!  A turbine on that lil ol thing?  What is it?

Pretty much it was one of those "We built it because we could" sort of things.

 

http://ronkilber.tripod.com/luscombe/luscombe.htm

[aviatoreb]

3 minutes ago, ragedracer1977 said:

Pretty much it was one of those "We built it because we could" sort of things.

 

http://ronkilber.tripod.com/luscombe/luscombe.htm

That's what I'm talking about.

[AH-1 Cobra Pilot]

Lots of weird numbers coming up on this thread.  You can make some pretty good estimates as to horsepower and fuel consumption using these.  (Keep in mind, the numbers presume roughly stoichiometric flow.):

As memory serves me, these are the common Specific Fuel Consumptions for these engine types:  Turbine = 0.43, gasoline recip = 0.36, diesel = 0.34.  All are in lbm/hp/hr.
As you can see, recips are 20-25% more efficient than turbines for the same horsepower.  The big difference is that turbines lose less capability at high altitudes.  You can also make your own estimations, such as this.  "I doubt it’s making 450HP if it’s only burning 17GPH."  Absolutely correct.  17 gal/hr * 6.8 lbm/gal ÷ .43 lbm/hp/hr = 269 hp.  (I use 6.8 lb/gal for jet fuel.  There may be some fudge to that.) 
You can also use this to correlate your fuel burn with your presumed %-power.  i.e. a J-model at 75% power should burn...150 hp * .36 lbm/hp/hr ÷ 6 lbm/gal = 9 gal/hr. 

Again, this is best-case-scenario.  If you run rich, your results may will vary.  I think a little Math can make us all better pilots.  Please try it for yourself.

 

P.S.  I may be too low on the recips.  This gives 10 gal/hr for the J-model, if you accept the number for the IO-720 here:  https://en.wikipedia.org/wiki/Brake_specific_fuel_consumption

[aviatoreb]

1 hour ago, Ah-1 Cobra Pilot said:

Lots of weird numbers coming up on this thread.  You can make some pretty good estimates as to horsepower and fuel consumption using these.  (Keep in mind, the numbers presume roughly stoichiometric flow.):

As memory serves me, these are the common Specific Fuel Consumptions for these engine types:  Turbine = 0.43, gasoline recip = 0.36, diesel = 0.34.  All are in lbm/hp/hr.
As you can see, recips are 20-25% more efficient than turbines for the same horsepower.  The big difference is that turbines lose less capability at high altitudes.  You can also make your own estimations, such as this.  "I doubt it’s making 450HP if it’s only burning 17GPH."  Absolutely correct.  17 gal/hr * 6.8 lbm/gal ÷ .43 lbm/hp/hr = 269 hp.  (I use 6.8 lb/gal for jet fuel.  There may be some fudge to that.) 
You can also use this to correlate your fuel burn with your presumed %-power.  i.e. a J-model at 75% power should burn...150 hp * .36 lbm/hp/hr ÷ 6 lbm/gal = 9 gal/hr. 

Again, this is best-case-scenario.  If you run rich, your results may will vary.  I think a little Math can make us all better pilots.  Please try it for yourself.

 

P.S.  I may be too low on the recips.  This gives 10 gal/hr for the J-model, if you accept the number for the IO-720 here:  https://en.wikipedia.org/wiki/Brake_specific_fuel_consumption

 

Well...its a forum - its fun to make up some numbers with artificial precision added for faux credibility and emphasis.

So I didn't know the efficiency factor constants you just stated thanks.

I agree a little math is good for pilots in general.  I am a math professor it is my business to teach math, that includes selling the concept of math, to a general population of engineering students as well as science students.