Radial Engine P-51 Mustang

[David E. Wells]

Re: Radial Engine P-51 Mustang

Look what happened when the Japanese ran out of inline engines for the Ki-61 and created the Ki-100 with a radial. Accidentally made a better airplane!

That was as much of an accident as it wasn't. Those DB600 type engines had a TBO of just 50hrs! MiG and Yakovlev also put M-82 radials on the MiG-3 and Yak-3 and made better airplanes (Well, the MiG wasn't so hot, but they stopped development short), as did Lavochkin when they came up with the Superior La-5. Part of the reason was the inline was vulnerable to damage in the cooling system and required lots of armor plate to protect it. The radial had a much longer TBO and was tough. Tom Dwelle tells the story of flying his Skyraider back home with the whole front row of cylinders shot off!...D.

[Paynts]

Re: Radial Engine P-51 Mustang

since I'm a brit and a fan of inlines don't leave the Sabre out of these Stats
* Type: 24-cylinder supercharged liquid-cooled H-type four-stroke aircraft piston engine
* Bore: 5.0 in (127 mm)
* Stroke: 4.75 in (121 mm)
* Displacement: 2,238 in³ (36.7 L)
* Length: 82.25 in (2089 mm)
* Width: 40 in (1016 mm)
* Height: 36 in (1168 mm)
* Dry weight: 2,360 lb (1,070 kg)#

* 2,850 hp (2,065 kW) at 3,800 rpm and 13 psi (0.9 bar) intake boost (bmep 265.4psi)
* 3,040 hp (2,200 kW) at 4,000 rpm war emergency power

# Specific power: 1.36 hp/in³ (59.9 kW/L)
# Compression ratio: 7:1
# Power-to-weight ratio: 1.29 hp/lb (2.06 kW/kg)

Pity they are rarer than hens teeth!!!

[AirDOGGe]

Re: Radial Engine P-51 Mustang

David I was interested to see you say you need 4000 hp and you cant get that out of a inline liquid engine without 2 stage supercharger etc

European formula 1 car racing engines long ago exceeded 100 hp per litre ( 60 cubic inches roughly) So surely money aside its possible to get up to 4000 hp given the low altitudes (Relitively) the Gold racers fly at
(I am more asking the question that making a statement, given the levels of expertise on this site its not wise to stick you neck out too far)

for instance a 1.5 ltre dispacement Turboed F1 engine in 1998 produced 1400 hp in qualifying at admittedly huge RPM
the current 2.4 litre engines naturally aspirated are making 750 hp

They are hitting higher horsepower levels that that these days. Almost unbelivable...

But, this is comparing apples and oranges, I have to say. F1 tech doesn't scale up very well. Actually, it doesn't scale up at all.

You are speaking of very small displacement engines, with tiny, lightweight, short-travel pistons that won't self-destruct at the 14,000 to 19,000 rpm levels, required to hit those horsepower-per-liter levels.

You'd never be able to get a large, long-stroke aircraft engine with coffee-can sized pistons to spin fast enough to make a significant difference without turning it into a piston cannon, launching it's pumpers like artillery shells, if the rods don't snap and chop the engine in half first.

Note also that the TORQUE level of these engines is no greater than the family station wagon V8, and you need massive torque to spin a large prop.

Long-stroke engines deliver more torque every time, as the pistons get more leverage from a larger diameter, longer-stroke crankshaft, but they don't rev as high as the shorties.

They can't. Piston speeds are far faster with a longer stroke engine turning the same RPM, so stresses are higher.

Gearing a high RPM, low torque engine for a prop would require quite a gearbox up front, and it would have to withstand the vibrations and twisting torque stresses that only a propeller spinning in dirty air can produce.

Developing such a gearbox that can bring you down from 10,000-15,000 rpm to the needed 2000-3000 and be sturdy enough to survive the workloads/vibrations would be prohibited-ly expensive to develop, with little chance of investment return, due to the small market for them.

These engines also cost so much to develop that you'd have a hard time just trying to buy one for sport class racing. They'll LEASE you one for a year for lot of money though.

For instance, JUDD will lease you one of their V8 F1 engines for a year/season for around $180,000 or so. Not the best deal in town for an air racer without a deep-pockets sponsor.


They do sound sweet though. Listen to this BMW running an F1 class Judd:

http://www.youtube.com/watch?v=fth3QyRkxes

Here. This describes the F1 motors best. Just not air racer material:

From Wikipedia about F1 engines:

Formula One currently uses four-stroke V8, naturally-aspirated reciprocating engines. They typically produce 224 kilowatts (300 bhp, 304 PS) per liter of displacement, far higher than most internal combustion engines.

The power a Formula One engine produces is generated by operating at a very high rotational speed, up to 20,000 revolutions per minute (RPM). This contrasts with road car engines of a similar size which operate safely at typically less than 7,000 rpm. However, the torque (turning force at a given speed) of a Formula One engine is not much higher than a conventional petrol engine.

For example, the 2006 2.4 liter Toyota RVX-06 V8 engine produces 552 kW (740 bhp, 751 PS) at 19,000 rpm and outputs only 274 N·m (202 ft·lbf) of torque giving the engine a 14.3 bar (1.43 MPa) mean effective pressure.

[hm66sk]

Re: Radial Engine P-51 Mustang

A Merlin can only rev so high before it self destructs. Sometimes before that! Coffee-Can pistons and a long arm = lots of mass to move up & down and roun' & roun'. That's why an engine is needed that develops the torque and HP at lower RPM's. = BIG. "There's no replacement for displacement."

[Skyracer]

Re: Radial Engine P-51 Mustang

A Merlin can only rev so high before it self destructs. Sometimes before that! Coffee-Can pistons and a long arm = lots of mass to move up & down and roun' & roun'. That's why an engine is needed that develops the torque and HP at lower RPM's. = BIG. "There's no replacement for displacement."

Or..."The only substitute for cubic inches is cubic dollars."

[Bob]

Re: Radial Engine P-51 Mustang

I dont understand why there are no big diesel two stroke engines for aircraft. It would have 1/2 the moving parts if that and no added weight for a super charger, expansion chambers to do that quite nice. And there is about 1/3more energy in diesel than gas I do believe. Just think, no pesky valve trains, no finicky 60year old ignition systems.
Just a thought

[AirDOGGe]

Re: Radial Engine P-51 Mustang

Well, I know 4-strokes get better gas mileage, and don't use up as much oil. More power from a 2-cycle engine might be good for racing, but aviation racing is a tiny market, while everyone who buys engines wants power AND long range. That may be part of the reason why.

[Race5]

Re: Radial Engine P-51 Mustang

I dont understand why there are no big diesel two stroke engines for aircraft. It would have 1/2 the moving parts if that and no added weight for a super charger, expansion chambers to do that quite nice. And there is about 1/3more energy in diesel than gas I do believe. Just think, no pesky valve trains, no finicky 60year old ignition systems.
Just a thought

You have to stick those big expansion chambers somewhere too.

[Bob]

Re: Radial Engine P-51 Mustang

I found a few links.
I guess there are some made for planes. Below is a great read about 2 stroke diesels for aircraft with up to 300hp for an air cooled 8 cyl two row radial.

Zoche Aero-Diesels, a German company developing radial aircooled two-stroke diesel engines, claims that its engine has been refined to the point where the engine delivers 58 percent more torque per liter of displacement than does a modern TCM IO-520 engine.

http://www.zoche.de/

http://www.experimentalaircraft.info/homebuilt-aircraft/aircraft-engines.php

http://www.deltahawkengines.com/

nothing big out there yet

[AAFO_WSagar]

My take on deux stroke

Used to have occaision to drive a pretty large three axle truck that was SEVERELY underpowered with a Detriot 6V-53... if you do the math, that's something like 318 cu in.. While that thing was a serious POS to deal with, went through more gears to get to 20 MPH (and beyond) then you can imagine, what we managed to load on that thing and then haul around the PDX area was pretty amazing!

I know it had a pretty low "suggested" max rpm but with what we hauled with it, we ALWAYS ran it up to about 3500 RPM (or more)..

I'm not talking a few lbs here, I'm talking up to 9+ pallets of 4000 lbs + roofing materials on her back..

All that work finally killed her and she went to the scrap pile but hate that sucker as we all did, the work we got out of those few cubic inches was pretty amazing!

Does this equate to racing potential?



Prolly not, the 6-53 in non supercharged versions is, I think, what powered most of the landing craft during WWII...

Not exactly cut out for racin' but we did work that engine HARD for many years.

[David E. Wells]

Re: Radial Engine P-51 Mustang

From "Soviet Combat Aircraft Vol.2" Y. Gordon & D. Khazanov: The Russians installed M-30B (ACh-30B) diesels in the Yer-2 Bomber very successfully, 1500hp, ran on kerosene, no danger of detonation, and flew the 29,761lb airplane at 267mph in 1943. It stayed in service after the war modified as a transport...D.

[wyhdah]

Re: Radial Engine P-51 Mustang

You know everyone is down on the inline engine but I haven't seen one round engine turn a single lap as fast as the lap average of dago in 2003.

I know the inlines have had some problems the in the last few years but some of the round guys have missed a few heats in the past with their own problems as well. We will probably be talking about how to get an inline in a bearcat five years from now when the roundies have a rash of problems.

[Leo]

Re: Radial Engine P-51 Mustang

I've had a similiar experience with diesel Wayne. I pull a 15,000 lb, 30' 5th wheel with a 99 Ford powerstroke. You can set the cruise control to 65 and it will climb over Donner without losing speed. All kinds of torgue and power. BUT, it is a dog for acceleration, pretty much you mash your foot to the floor and wait for everything to spool up!
There are goodies out there to solve that if you are the type to modify.
Does the same equate to aircraft engines? That lag would be a killer, kind of like the early jets.

[Skyracer]

Re: Radial Engine P-51 Mustang

I pull a 32' fifth wheel with my 2006 GMC Duramax (about 19,000 lbs GCW, 360HP, 650LbF Torque). HOLY CRAP!!!, whatever I set the cruise at is what it does, uphill, downhill, and in between. No problem with acceleration either. Is kinda kewl when some hot dog in his tricked out, turbocharged, intercooled, NOS'd Honda wants to race me on a freeway entrance; can't touch me until I back off at 75 or so.

OK, back to airplanes.

[First time Juke]

Re: Radial Engine P-51 Mustang

----snip----But maybe with the proper engineering anything is possible. Lear wings or standard Mustang clipped wings. I am thinking about doing a drawing to see what it would look like. ---snip--- Build the Fuselage up from scratch and not use existing airframes. ---snip---- I saw a early concept drawing of the Mustang During the Production of the Stang with I think were forward sweep wings. Shown in a Publication.

Mark----- May the Mustang Rule again

I also drew a plane with a R 3350 with forward sweep wings. In fact Heinkel H 100 V-8 did have mild forward sweep and later Heinkel desing ( 546 mph design ) had 8 degrees forward sweep.

If one gets 10 mph per a mod...how fast would a Stang go with these ?

1. Sweeped wings
2. Flying elevator
3. Thinner wing foil
4. Straight leading edge wing
5. Shorter wing
6. More HP:s
7. Thinner fuse
8. Less weight
9. Modified canopy
10. NACA type inlets

From 410 mph to 510 mph or more ?

I personally don't think radial fits a Mustang.



Happy New Year !

rgds,

Juke