Radial Engine P-51 Mustang

[Bigfoot]

Re: Radial Engine P-51 Mustang

Radial Engine Mustang???

Seems rather pointless doesn't it???

[Skyracer]

Re: Radial Engine P-51 Mustang

Radial Engine Mustang???

Seems rather pointless doesn't it???

No.

[hm66sk]

Re: Radial Engine P-51 Mustang

Radial Engine Mustang???

Seems rather pointless doesn't it???

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! Since Merlins are running short, I always thought of a P-51 with a 4360 in front. I've got a drawing somewhere I made years ago of the concept. I'll see if I can find it to post.

[David E. Wells]

Re: Radial Engine P-51 Mustang

I don't know if/why anyone would want to put up their P-51 for such a thing. But, what about that glass 'replica' P-51 that some guys are doing for an Allison?...D.

[440_Magnum]

Re: Radial Engine P-51 Mustang

The book is "US Fighters" by Lloyd S. Jones. The book,pg.117 & 118, has both a picture of it plus the write up. They converted 2 P47s & installed the Chrysler XIV-2220-1 16-cylinder inverted Vee liquid-cooled engine which produced 2300hp.It was stated to reach 490mph in level flight. Not developed because the Chrysler engine never went into production.Big & not pretty.

Well, the engine itself is VERY pretty, in fact a thing of great beauty with the reduction gearing tucked neatly in between the front and rear sections of 8 cylinders each:

http://upload.wikimedia.org/wikipedia/en/2/24/Chrysler_IV-2220.PNG

But the installation in the P-47 was.... not.

FWIW, it didn't go into production for the same reason the Bearcat never saw combat in WWII- the war, thankfully, ended before it was ready.

[hm66sk]

Re: Radial Engine P-51 Mustang

I don't know if/why anyone would want to put up their P-51 for such a thing. But, what about that glass 'replica' P-51 that some guys are doing for an Allison?...D.

Even better! When I had the idea, there was no such thing as replica. If we're going down that road, there are lots of fiberglass airframes. Don't know how many (if any) could handle the horses though without some SERIOUS modifications. Probably easier to start from scratch.

[David E. Wells]

Re: Radial Engine P-51 Mustang

For the return you get, i.e., Prize $, vendor sales etc. starting from scatch doesn't appear to be practical given the costs to develop a full-blown Gold racer. Look where Matt Jackson's project is, or Greenamyer's...on the hangar floor for Years. The Mustang is The Perfect mix of wing, fuselage, and size, But they've become Historical Treasures. Wouldn't it be more practical to have a "stock" class? I've long advocated a "Heritage" Class, scored on Historical originality, Race Performance, and Peoples Choice. "Luscious Lisa" raced last year dead stock, no ADI, no spray-bars, 61in/3000rpm, and did pretty well because she was Flown Very well. That Glass Mustang interested me because there you have the ability to manufacture the Best airplane and Engine it with anything that fits. BUT, to Beat The Bear or Sept Fury with a Mustang you'll need something close to 4000hp and you can't get that out of a liquid-cooled powerplant without a 2-speed, 2-stage blower, some Mysterious modifications and some Fine Flyin'...D.

[Paynts]

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

However as stated elsewhere given levels of sponsorship and prize money in unlimited racing compared to F1 its all highly academic

[hm66sk]

Re: Radial Engine P-51 Mustang

to Beat The Bear or Sept Fury with a Mustang you'll need something close to 4000hp and you can't get that out of a liquid-cooled powerplant without a 2-speed, 2-stage blower, some Mysterious modifications and some Fine Flyin'...D.

Hence the 4360 and the glass Mustang!

[hm66sk]

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

However as stated elsewhere given levels of sponsorship and prize money in unlimited racing compared to F1 its all highly academic

Top Fuel engines produce over 4000 h.p with less than 1000 c.i. but, they are on the rabid edge and are freshened up after every round. 1/4 mile at a time. I don't know how one would build a Merlin with those kinds of power levels per cubic inches and have any reliability and longevity left!

[David E. Wells]

Re: Radial Engine P-51 Mustang

However as stated elsewhere given levels of sponsorship and prize money in unlimited racing compared to F1 its all highly academic

EXACTLY! We're dealing with airplanes that were DONE when the Me-262 was invented. AND, as hm66sk states, Top Fuelers get BIG hp for 6sec... we're looking for maybe 10min., which is all Dwight Thorn expected a Mouse Motor to last at 130"+! Those motors went for $150k+, what's a F1 motor go for, or for that matter a Top Fueler? Their Prize $ & Sponsorship will, at least, keep them tryin' How do you secure BIG BUCKS Sponsors for a Venue with diminishing resources? We're just trying to keep the juices of Nostalgia flowing. I, for one, want to see these planes flyin' around the pylons for many years to come, why not slow 'em down a little and let the fans determine the "Winners".
That composite P-51 may just be what the doctor ordered. It's gotta be lighter. I don't think the Allison is the answer, but a 3350...a 4360 might be a bit heavy for the smaller airframe, I think, but I don't really know...D.

[RAD2LTR]

Re: Radial Engine P-51 Mustang

Top Fuel engines produce over 4000 h.p with less than 1000 c.i. but, they are on the rabid edge and are freshened up after every round. 1/4 mile at a time. I don't know how one would build a Merlin with those kinds of power levels per cubic inches and have any reliability and longevity left!

I have to agree. When you nuke a top fuel engine you coast to the end of the track and get towed back. When you are doing close to 500 mph and the thing lets go one has few options aside from going down in one way or another. If it were me, I'd opt for an engine that doesn't need a full rebuild after each race. Comparing a top fuel engine to a race Merlin is like comparing an apple and a strawberry. Both are engines but entirely different.

The issue I see with running a radial on the front of a P51 is that there would be a lot more frontal area with the radial, and more frontal area equals more drag (generally) and requires more power to over come the drag. Don't get me wrong, I love radial engines, however they are equally susceptible to self destruction/ relyability issues as a water cooled engine if its been tweaked enough and or can't cool well enough. With 4 rows of cylinders, that back row has a lot of heat to contend with and not a lot of cool air flowing over the cylinders. The other issue with the R4360 is its a big engine. With that much weight up front, the C/G must be moved way back to correct this. A 3350 might be a better choice as they are reliable even with large amounts of power, they are lighter/ shorter, and with only 2 rows of cylinders it should cool better.

With a composite airframe and a 3350 with no scoop and a boil off system not only would it be light but it could be really fast if the frontal area can be cleaned up enough. Its a cool concept on paper, I'd love to see how it would do in real life.

Will

[hm66sk]

Re: Radial Engine P-51 Mustang

Some quick figures I pulled off WIKI to stimulate the conversation.
R-4360:
Length: 96.5 in. (2 451 mm)
Diameter: 55 in (1397 mm)
Dry weight: 3,870 lb (1,755 kg)
Power output: 4,300 hp (3,210 kW)
Specific power: 0.99 hp/in³ (45.0 kW/L)
Power-to-weight ratio: 1.11 hp/lb (1.83 kW/kg)

R-3350:
Length: 78.14 in (1985 mm)
Diameter: 55.62 in (1413 mm)
Dry weight: 2670 lb (1212 kg)
Power output: 2700 hp
Specific power: 0.81 hp/in³
Power-to-weight ratio: 1.0 hp/lb

Pros-Cons people? I read that Matt Jackson is thinking of changing the engine in his "American Spirit" from the Wright to the P&W. Must be a reason? Also, the guys running the corn-cobs are using a spray bar type arrangement to cool the cylinders so, maybe that's (the cooling) not as big of a problem as we think! Keep the thread going! I like to dream.

[Skyracer]

Re: Radial Engine P-51 Mustang

And the Merlin (61):

Length: 88.7 in (225.3 cm)
Width: 30.7 in (78 cm)
Height: 40 in (101.6 cm)
Dry weight: 1,640 lb (745 kg) (Dry)
Power Output: 1,565 hp (1,170 kW) at 3,000 rpm at 12,250 ft (3,740 m) (MS gear)
Specific power: 0.95 hp/in³ (43.3 kW/L)
Power-to-weight ratio: 0.95 hp/lb (1.57 kW/kg)

[hm66sk]

Re: Radial Engine P-51 Mustang

Good call to include. Lets throw the Ally in there too.

Length: 98.53 in (2,502 mm)
Width: 29.28 in (744 mm)
Height: 41.18 in (1,046 mm)
Dry weight: 1,445 lb (655 kg)
Power output: 1,325 hp (988 kW) at 3,000 rpm (bmep=204.5 psi)
Specific power: 0.77 hp/in³ (35.3 kW/L)
Power-to-weight ratio: 0.92 hp/lb (1.51 kW/kg