Fastest Piston Engine

[PWR4360-59B]

Just curious if anyone knows what engine powered the fastest vehicle?
I have some ideas but just curious what others would have to say.
I would say the first was a BMW.
I'm not saying what I'm thinking the last and probably the fastest would be, don't want to get laughed at.

 

[Colin1]

I seriously doubt anyone's going to laugh at you
At the risk of sounding pedantic, I'd only question your title: Fastest Piston Engine
Most powerful piston engine possibly? You do go on to say fastest vehicle, which seems more appropriate and with good reason; at that end of the performance regime, the airframe is going to be the limiting factor. A classic example would be the Merlin 61 in the Spitfire IX; the same engine in the P-51 provided a platform that was some 25mph faster.

Then there's power to weight. Staying on the P-51 theme, the P-51H had, I believe, less available horsepower in the -9 Merlin than the P-51D had with the -7, yet was capable of 487mph@25,000ft, some 50mph faster than its predecessor. Both empty and normal take-off weight for the H were some 600lb lighter than those for the D though.

How did brutes like the late-variant R-2800/3350s compare with the late-variant Merlins and Allisons (who came good toward the end of the war)?

Just some fuel for the debate, sorry I couldn't go into more depth, I've got a long drive ahead of me today and need to get ready. Hopefully, it will be in full swing for my return.

 

[Shortround6]

A big qualifier would be when?

The 1930s?
end of WW II?
Modern air racers?

as far as vehicles goes, air speed, land speed or water speed?

 

[vikingBerserker]

I belive it's the Wright R-3350 fitted into an F8F Bearcat named Rare Bear at 528mph.

 

[robwkamm]

ive read some were that the p47m did over 500 mph in level flight and was the fastest at the end of ww2. we need to nail down a time period for this list.

 

[FLYBOYJ]

I belive it's the Wright R-3350 fitted into an F8F Bearcat named Rare Bear at 528mph.

Officially this is the absolute world record speed for a recip aircraft.

 

[PWR4360-59B]

Yes I'm reffering to recip engines, and reffering to what the fastest vehicle would be that one propelled.
I'm thinking the first case was in the WWII era, and was a very unconventional craft, and probably not an offcial record.

And if an R-3350 could make an old airframe like that scoot at those speeds imagine what a more aerodynamic airframe could do.

 

[fastmongrel]

A Spitfire XI Photo Recon plane was recorded doing 606 mph in a deliberate near vertical dive just before the propellor came off. Amazingly the pilot F/Lt Martindale managed to land

 

[wuzak]

The "Dilly Mustang" was clocked at just over 530 MPH by ATC Radar at, IIRC, about 5K' AGL. Not an official record, but a bunch faster than the Spit at 606 in a near vertical dive will go in horizontal flight? It was also not at max power, but cruising between points across the wind. Again IIRC.

Firstly, the 606mph was recorded in a 45° dive and was to investigate aerodynamic behaviour at high mach numbers.

It is no surprise that a highly modified WW2 era fighter, stripped of all its military equipment and having its engine tuned to around double the original's power and being smoothed and otherwise aerodynamically modified, would be faster in a straight line than a standard WW2 fighter (or in the case of the Spitfire XI, a PR aircraft).

I, however, doubt that the "Dilly Mustang" would be able to scoot along in a 390mph cruise at 30,000ft+ for several hours.

 

[GregP]

With regard to post #7 above, Rare Bear is nowhere close to a stock airfame. It has radical modifications, completely different from stock wing and tail airfoils, and almost none of the original Grumman stuff inside. It is basically a custom airframe with systems largely designed and built by Dave Cornell. There are almost no stock controls anywhere in the cockpit with the exception of the control stick and throttle / mixture.

The landing gear is a "one-shot" unit that will retract once, MAYBE twice before running out of compressed air. The oil cooler is a boil-off unit. The canopy is basically formula 1 style.

The drag is MUCH lower than any close-to-stock Bearcat. Couple that with something like 4,400 HP and you get a world record. Rare Bear is very fast, but unfortunately is not optimized for turning at Reno's typical density altitude ... the aspect ratio is a bit low for that. In a straight line, though, it is VERY close to both Strega and Voodoo in speed capability.

There is no system in Rare Bear that would be suitable for flying any military mission, let alone any normal military use. It is totally optimized for racing and is pretty much useless for anything else.

 

[CORSNING]

I like the idea of limiting a time frame. Someday a piston engine aircraft might exceed 600 mph.
in level flight through a neutral atmosphere. Anything is possible. If you want the straight info from
WW2 then this is your answer:
The Republic P-47M, The Fastest Piston Engine Fighter Of The War.... There punch that in to Google.

Well, that's just me, Jeff

 

[VALENGO]

Long time ago I´ve read that the limiting factor was the onset of supersonic speed in the propeller tips. Anyone can confirm this?.
Thanks in advance.

 

[GregP]

True. When the prop tips go supersonic, there is a huge increase in prop drag. So ... you need a prop that can get to very coarse blade angles. Don't think a prop-driven plane will ever go supersonic, but they COULD go faster if a concerted effort were to be made.

The problem with that is the cost-to-benefit ratio is terrible. If you did it, you would never recoup the cost of doing so. At this point in time, I think Strega, Voodoo, and Rare Bear could all beat the existing record, but the cost is near $1M- US for an attempt and it's just not worth it.

 

[Shooter7.62]

Firstly, the 606mph was recorded in a 45° dive and was to investigate aerodynamic behaviour at high mach numbers.

It is no surprise that a highly modified WW2 era fighter, stripped of all its military equipment and having its engine tuned to around double the original's power and being smoothed and otherwise aerodynamically modified, would be faster in a straight line than a standard WW2 fighter (or in the case of the Spitfire XI, a PR aircraft).

I, however, doubt that the "Dilly Mustang" would be able to scoot along in a 390mph cruise at 30,000ft+ for several hours.

Since the Mustang, in full military form only needs about 1,200 HP to go 390 MPH, I have no doubt that the Dilly Mustang could scoot along at more than 440 MPH for as long as it had gas.

As to other planes put forward as the fastest this or that, the P-51H @ 487 MPH was easily the fastest plane to go into service in WW-II. They made 555 during the war, but could not get any into the action because the A-Bombs cut the war short, but they were there and ready.

Other contenders, none to speak of except the P-47J prototype! See below from Wiki;

The XP-47J began as a November 1942 request to Republic for a high-performance version of the Thunderbolt using a lighter airframe and an uprated engine with water injection and fan cooling. Kartveli designed a completely new aircraft fitted with a tight-cowled Pratt & Whitney R-2800-57 with a war emergency rating of 2,800 hp (2,090 kW), reduced armament of six 0.50 in (12.7 mm) machine guns, a new and lighter wing,[18] and many other changes. The only XP-47J was first flown in late November 1943 by Republic test pilot Mike Ritchie. Less than a year later it flew into the aviation history books marking a new milestone for speed.[19][page needed]

When fitted with a GE CH-5 turbosupercharger, the XP-47J achieved a top speed of 505 mph (440 kn, 813 km/h) in level flight on August 4, 1944 at 34,500 feet over a course in Farmingdale, New York, piloted by Mike Ritchie.[18] Ritchie's achievement was not exceeded until August 21, 1989, when Lyle Shelton piloted Rare Bear, a highly modified Grumman F8F Bearcat, and set a new official FAI record at 523.586 mph.

 

[wuzak]

Since the Mustang, in full military form only needs about 1,200 HP to go 390 MPH, I have no doubt that the Dilly Mustang could scoot along at more than 440 MPH for as long as it had gas.

Maybe.

What is the cruise power for that engine? Probably not too different from stock.

How much less drag does the airframe have from a stock P-51?

Also note that the Spitfire XI was in cruise settings when doing 390mph at over 30,000ft. That means, most likely, less than 1,200hp.

Max cruise power of the 63 was around 1,000hp, 2,650rpm @ +7psi boost.

As to other planes put forward as the fastest this or that, the P-51H @ 487 MPH was easily the fastest plane to go into service in WW-II. They made 555 during the war, but could not get any into the action because the A-Bombs cut the war short, but they were there and ready.

Other contenders, none to speak of except the P-47J prototype! See below from Wiki;

The XP-47J began as a November 1942 request to Republic for a high-performance version of the Thunderbolt using a lighter airframe and an uprated engine with water injection and fan cooling. Kartveli designed a completely new aircraft fitted with a tight-cowled Pratt & Whitney R-2800-57 with a war emergency rating of 2,800 hp (2,090 kW), reduced armament of six 0.50 in (12.7 mm) machine guns, a new and lighter wing,[18] and many other changes. The only XP-47J was first flown in late November 1943 by Republic test pilot Mike Ritchie. Less than a year later it flew into the aviation history books marking a new milestone for speed.[19][page needed]

When fitted with a GE CH-5 turbosupercharger, the XP-47J achieved a top speed of 505 mph (440 kn, 813 km/h) in level flight on August 4, 1944 at 34,500 feet over a course in Farmingdale, New York, piloted by Mike Ritchie.[18] Ritchie's achievement was not exceeded until August 21, 1989, when Lyle Shelton piloted Rare Bear, a highly modified Grumman F8F Bearcat, and set a new official FAI record at 523.586 mph.

Spiteful XVi went 491mph.

The XP-47J would not have held an FAI record in any case, since it was done outside the required altitude.

 

[wuzak]

Since the Mustang, in full military form only needs about 1,200 HP to go 390 MPH, I have no doubt that the Dilly Mustang could scoot along at more than 440 MPH for as long as it had gas.

And how long would that be?

Given that it was a racing aircraft with non-standard wings I presume the tankage was somewhat reduced.