# If a WWII fighter engine were produced with today's technology, what would we get?



## CobberKane (Apr 11, 2013)

It's easy to forget that the technology that produced the great aero-engines of WWII is seventy years in the past. On a power to capacity ratio the motorcycle in my carport makes a Rolls Royce Griffin look puny. So, forget the jet engine ever happened- if we designed an engine of the same dimensions as those used in the Spitfire, 109 or Thunderbolt with today's technology, how much power could we get? What would be the limiting factors? Where the hell is Lord Lucan? Answer these questions and eternal fame will be yours.


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## wuzak (Apr 11, 2013)

Firstly, it is unfair to compare the specific power of a Griffon to that of a motorcycle because the power figures are measured differently. While a Griffon's rate combat/WEP is usually authorised for 5 minutes testing requires it be able to take that for longer. The Griffon also had to pass a type test, which required running at different loads for over 100 hours (UK type test was 114 hours, I think).

Secondly it is far easier to extract high specific powers from small cylinders.

Rolls-Royce's Stewart Tresilian proposed an X-16 engine of 10.3l (approx) with a maximum rpm of 7,500rpm. The supercharger would be taken directly from the Griffon, and would be the biggest part of the engine as seen from the end.

I should imagine that is the sort of thing we would see. It would be small, light and compact.

If you really require Griffon capacities then I would think an X-24 or H-24 using similar dimensions to the Sabre (Bore 5", stroke 4.75"), or an X-16 still with over square dimensions. 

For an engine of Merlin capacity I would think an X-16 would do the job. If you really needed a V-12 of that capacity the bore would probably go to 6" and stroke to 5" (Merlin bore 5.4", stroke 6"; Griffon bore 6", stroke 6.6"). Rev capability would go up, and so would horsepower.

For a V-12 with short stroke and Griffon bore the power output would match historical Griffon power figures at a bare minimum.


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## CobberKane (Apr 11, 2013)

My comarison of a Griffon to a modern motorcycle engine was flippant, to its also true that a motorcycle of the 1930s produced only a fraction of the power mine does. Let,s look at another way - if we were tasked with producing and engine today with similar output to the Griffon, what would it's configuration and capacity be with today's technology?


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## Shortround6 (Apr 11, 2013)

There were a few things going on that do not scale well. 
No 1 is that the fuel/air mixture burns at the same speed regardless of the size cylinder it is in. WW II practice was to use fixed ignition timing with the goal of getting the the flame front to cross the cylinder ( fuel burn pretty much completed) when the piston was at a position that corresponded to being 20 degree past top dead center. This tended to limit the RPM that could be used or the cylinder size or both. Now we can use variable ignition timing (more advance) at higher rpm but that is only going to go so far. WW II engines were using dual ignition both for reliability and to get two flame fronts to complete the burn quicker. For PEAK power you can let the piston go lower in the cylinder before the fuel burn is complete but that doesn't help fuel economy much  

As Wuzak has said it is easier to get power from smaller cylinders, one reason is cooling, if you double the bore of a cylinder you have increase the displacement (and the amount of fuel burned ) by four but only increased the area of the cylinder wall by 2. Granted the cylinder head has grown but you are trying to get rid of more heat per unit of wall/head area. You have also increased the distance heat must travel from the center of the piston to the cylinder walls. Yes we have better materials. 

As Wuzak has already said, those engines were TYPE tested which means that they were deliberately run at less than full _ possible_ power in the interest of both longevity and reliability. The US standard for WER was the test engine engine had to survive 7.5 hours at the WER rating in 5 minute bursts. How well could you motorcycle engine stand up to NINETY _full throttle_ (held at peak power) 5 minute hill climbs without a teardown? A few of those engine were pushed to considerably higher power levels in testing in test houses ( a large airplane engine coming apart at high speed is a pretty catastrophic event and it is best to have concrete walls between the engine and any operators).


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## Airframes (Apr 11, 2013)

Are we discounting turbo-prop? If not, then the possibilities are huge.


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## wuzak (Apr 11, 2013)

Airframes said:


> Are we discounting turbo-prop? If not, then the possibilities are huge.



When the OP suggested no jets I think he probably meant no turbines - jets, turboprops/turboshafts.


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## Airframes (Apr 11, 2013)

Shame - there could be some interesting thoughts there.


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## dobbie (Apr 11, 2013)

CobberKane said:


> It's easy to forget that the technology that produced the great aero-engines of WWII is seventy years in the past. On a power to capacity ratio the motorcycle in my carport makes a Rolls Royce Griffin look puny. So, forget the jet engine ever happened- if we designed an engine of the same dimensions as those used in the Spitfire, 109 or Thunderbolt with today's technology, how much power could we get? What would be the limiting factors? Where the hell is Lord Lucan? Answer these questions and eternal fame will be yours.




Nothing really wrong with the WWII designs per se-they are sound designs even for today. The increased capability would be mostly centered around the use of better/lighter/stronger alloys which would allow higher continuous RPMs from lower rotating mass, computer controlled ignition and direct injection systems and much improved supercharging.


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## yulzari (Apr 11, 2013)

Perhaps a closer guide to the use of modern materials and technology is the Formula 1 engine. Simplisticly put, in @1970 it produced 400 bhp at 10k rpm. 40 years later it could put out 950 bhp at 20k rpm (rpm was then limited by the rules.).

This suggests that new materials and ignition control only increased the power from 13.33 bhp per litre per 1k rpm to 15.83 per litre per 1k rpm or barely 19%. The bulk of the total power increase came from the increase in rpm. As the late Keith Duckworth used to say; horsepower is the size of the bang multiplied by the number of bangs per minute.

So 40 years of intensive research increased the size of the bang by 19%. It did double the number of bangs per minute.

Now the sheer mass of a WW2 engine is not going to double in rpm even with the best modern materials. However it would increase with all the caveats such as increased power loss in gearing to keep propellor tip speed within practical limits.

There is a WW2 period example in the Napier Dagger where Halford tried to increase revs with smaller cylinders in just such a pursuit.

Where it might lead to is smaller engines to gain in revs what it loses in capacity and modern engine management and fuel blending will allow higher boost pressures also so my prediction would basically be as per Tresillian's high boost X16 10 litre with electronic ignition mapping and high temperature tolerant fuel blends.

This would be for fighters. Large bombers and maritime search/strike would go down the fuel/weight efficient route with turbo diesels with all possible energy put back into the engine. In other words if fighters have a high tech Napier Dagger then bombers would have a high tech diesel Napier Nomad.

There are considerable returns to come from supersonic propellor blades using high rpm without heavy and power wasting gearing (and horrible shock wave and acoustic issues).

A Tresillian 10 litre X16 is about 1,000bhp at best Merlin comparison, 1,200 bhp with modern 'bangs at 3,000rpm, 1,800 at 4,500 rpm and fit in an airframe of half the dimensions of a Spitfire so vastly less weight. Certainly it could approach transonic speeds.

However, once you start playing with the drive methods then you approach a grey area. When does a ducted fan become a fan jet. I think that exploring the use of a piston engine to power a compressor and burning fuel in the compressed air will inevitably result in someone linking the compressor to the high pressure burning exhaust to drive it and invent the jet engine anyway.


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## GregP (Apr 11, 2013)

Been inside a lot of Allisons and they are 4-vavles per cylinder with overhead camshafts that are gear driven, so the technology is pretty good. You might remember that 35 years ago or so, we did tune ups every so often, to the tune of about every 6,000 miles or so. Today most cars can go 100,000 miles between tuneups.

Did something magic happen? No, we went to direct fuel injection, so each cylinder gets a correct mixture and we don't have some running rich while others run lean. I think moving to direct fuel injection would cure MANY WWII engine woes and extend the life. With today's technology, I think you could get 2,500 HP from something like 1,000 cubic inches and still have reliability and logevity for aerial application. It would probably have several turbbochargers in addition to the supercharger and the mixture could be made automatic. The avionics would be glass panels and the capability would be staggering.

Since we are moving to modern technology, we could go to a pusher if one rotary cannon is used or two in the wings if a tractor layout is used. It wouldn't need as many bombs because they'd be smart bombs or even retarded smart bombs (with devices to slow the bomb so the aircraft can escape the blast at low altitude) or even cluster ammunition. A P-51 like plane with a rotary cannon or two, smart ammunition, and 4 sidewinders would be a tough customer.

Conversely, if WE had them, then Germany would also have them, and the fight would get even more costly than it was. It certainly wouldn't drag on for 5 1/2 years with today's technology! Might be over in less than 6 months. If the powers remained the same, then the Battle of Britain might well have been successful unless we presuppose that the modern Bf 109 also had very short legs. Even if true, 15 minutes over England with smart ammunition and air-to-air missiles might make a huge difference in outcome, not to mention the participation of attack helicopters that surely would spring up with all those neat engines available.

Of course, with modern technology, we'd KNOW they were coming, how fast, from where, and would probably just send the drones in to take out the forward airfields, so maybe they wouldn't make it across the channel unless they drove through the tunnel in force in BMW armored cars or everyone caught the scheduled hovercraft at the same time.

Some really important developments are the vast improvement in submarines and the vast improvement in main battle tanks. I bet the trusty German BMW sidecar motorcycle would change somewhat, too!

There have been a number of adventure / science fiction novels written around this very premise, and somehow the Nazis still manage to lose ... on paper, but wreak incredible havoc as they do so. I liked the movie "Final Countdown," where a modern aircraft carrier was dragged into 1941 the day before Pearl Harbor. An F-14 versus an AT-6 made up to look like a Zero was pretty entertaining! The 1941 people were blown away by the arrival of turbine helicopters.

Maybe all we'd really have to do to stop Germany is disable their internet and business wopuld grind to a halt. I'm also fairly sure the press would not be allowed to transmit front-line battle pics around the world like they do now.


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## vinnye (Apr 11, 2013)

You might have seen reliable high hp versions of the Sabre engine that were reliable from the start. 3000+ hp on tap - put a decent contra rotating prop on it and you have a good starting point!


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## CobberKane (Apr 11, 2013)

I'm way behind you guys in engineering nous, but it seems to me that the following post WWII developments would have the greatest effect on output
1. Electronic ignition
2. Electronic fuel injection
3. Turbo/supercharger technology

Of course, then increased level of tuning is going to have ramifications for engine wear and reliability, but we also have options like metalurgical advances and ceramics to help.
The elephant in the room would be cooling, I guess. Could some sort of evaporative system be made to work, and be more efficient?
One other thought - the post proscribes jets, and by inference turboprops, but what about Wankel rotaries? Any potential there?


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## GregP (Apr 11, 2013)

I used to race Wankels in the SCCA (Sports Car Club of America), and have seen the Mazda 3-rotor Wankels run. It's a pretty decent engine when displacing 1,200 or 1,300 cc (the 12A and the 13B), but as it gets bigger, it runs into problems. The power is smooth, but you have to bridge-port it and put in racing apex and tip seals to make any decent horsepower, and you have to pin the main rotor gear (in 3 places) to keep it from slipping in the mount at high RPM.

They aren't bad as small engines but I'd have to see a big one run well before making any bets on it. I'd say stick with a piston and race the tiny Wankels in Austin-Healey Sprites / MG Midgets. WAY fun. 

When pinned and bridge ported, we got 225 - 235 HP out of it and had them in Sprites with an all-up racing weight of 1,500 pounds (minus the driver). They were QUICK! You could do a street port job and get 170 - 180 HP and have a Sprite that could beat a Corvette ... just use the Mazda running gear and manual transmission. You had to beat the heater box in to get the bell housing to fit and had to come up with a transmission mount yourself, but it was worth the effort. Wish I still had one!


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## wuzak (Apr 11, 2013)

yulzari said:


> Perhaps a closer guide to the use of modern materials and technology is the Formula 1 engine. Simplisticly put, in @1970 it produced 400 bhp at 10k rpm. 40 years later it could put out 950 bhp at 20k rpm (rpm was then limited by the rules.).
> 
> This suggests that new materials and ignition control only increased the power from 13.33 bhp per litre per 1k rpm to 15.83 per litre per 1k rpm or barely 19%. The bulk of the total power increase came from the increase in rpm. As the late Keith Duckworth used to say; horsepower is the size of the bang multiplied by the number of bangs per minute.



It isn't just the rpms that drove power up. The increased rpms needed a lot of work in the combustion chamber and the intake and exhausts to maintain the BMEP to a high enough level such that the added rpms gave benefit.

In 1989 turbos were outlawed. The new engines were 3.5l V8s, V10s and V12s. They made between 700 and 750hp, revved to around 14-15,000rpm.

Compare that the current engines - 2.4l V8s revving at 18,000rpm (restricted - unrestricted, in the 2006 season, the engines would regularly see over 19,000rpm and were able to crack 20,000rpm in testing) making approximately 720hp. 

The increase in rpms came about through ever more extreme bore:stroke ratios. The current V8s have a maximum bore of 98mm which has led to tiny strokes of less than 40mm.


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## syscom3 (Apr 11, 2013)

The R2800, R3350 and R4360's all had continued development after the war. I think the R4360 had the ultimate evolution in design by being a turbo compound design with some type of "jet effect" being harnessed by the large quantity of hot exhaust.

What did these engines in, was the enormous fuel consumption with relatively low efficiency. And they were maintenance nightmares from the get go.


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## wuzak (Apr 11, 2013)

CobberKane said:


> I'm way behind you guys in engineering nous, but it seems to me that the following post WWII developments would have the greatest effect on output
> 1. Electronic ignition
> 2. Electronic fuel injection
> 3. Turbo/supercharger technology
> ...



Those are very important factors.

I would add that the fuel injection would probably be direct injection. This would aid in efficiency.

Materials is an area which would improve the engine, as stated above. Computer aided design/finite element analysis would allow the engine to be more compact and lighter weight while maintaining reliability and strength.

Piston design would be updated to modern slipper piston types.


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## nuuumannn (Apr 11, 2013)

Electronic engine management would contribute to almost every facet of powerplant operation, from fuel distribution and consumption, spark timing, propeller pitch governing etc. Such changes in the fabric of the engines themselves would certainly see changes in the way the entire airframe and systems were managed and the way that information was presented to the pilot. As things are today, avionic systems would proliferate and more black boxes would be shoe horned into nooks and crannies around the airframe. More Spooks = fewer guys on the hangar floor getting dirty!

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## tyrodtom (Apr 11, 2013)

Oh no, a F-35 with a prop.


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## GregP (Apr 11, 2013)

At cruise (1,300 HP) the R-3350 is about 100 US gph per engine and the R-2800 is about the same or very slightly less for about 100 less cruise HP. You CAN get them a bit less, but you risk the engine if you lean too much. 

You can get a Merlin 66 down to about 55 US gph per engine but any lower and you risk being too lean and having a very expensive event experience. We figure them at 60 US gph and don't really lean it any further than that these days. Maybe in WWII, when a government was paying for the engine, maintenance, and overhauls, you could get down to 46 US gph per engine, but NOBODY does that today since WE pay for the mistakes.


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## GregP (Apr 11, 2013)

If I were specifying the avionics today, I'd want a reliable system that give good performance, but not the best that can be gotten. I'd rather have a reliable very good plane out there in numbers than the absolute best plane in fewer numbers that usually sits in the hangar being worked on.

Gimme' a Skyraider with modern avionics, a modern engine of 3,500 HP, and some smart weapons and I'll show you what an attack plane can do! I want the rotary cannons, too! No more rat-tat-tat ... more of a hummmmm ... and target gone. I'd rathre have a turboprop, but if that's out, a piston did just fine in the real beast, so it should do at least as well with a more reliable modern engine.


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## bob44 (Apr 11, 2013)

I can see a couple of big things being different today beyond any advances in materials and design. First would be electronics/computers, the second would be emission controls. 
The better materials and designs should get more hours and performance out of an engine, but the complex electronics would mean longer/more cost to produce and repair.


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## nuuumannn (Apr 11, 2013)

A big problem with modern aircraft and their avionics issues is not the individual pieces of equipment, but interface between systems. Different manufacturer's software can't always understand each other and isn't compatible and in R D that's the biggest cause of delay with electronic systems of modern aircraft than any other. Look at the Australian Seasprites as an example, other issues aside, of cramming too much gadgetry into an existing airframe in a misguided aim to produce extraordinary capability where it never previously existed and the result is an unuseable aircraft.


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## gumbyk (Apr 12, 2013)

nuuumannn said:


> A big problem with modern aircraft and their avionics issues is not the individual pieces of equipment, but interface between systems. Different manufacturer's software can't always understand each other and isn't compatible and in R D that's the biggest cause of delay with electronic systems of modern aircraft than any other. Look at the Australian Seasprites as an example, other issues aside, of cramming too much gadgetry into an existing airframe in a misguided aim to produce extraordinary capability where it never previously existed and the result is an unuseable aircraft.



and the antithesis of this is the RNZAF A4's (when we still had them), Orions, etc


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## GregP (Apr 12, 2013)

An A-4 with modern avionics and a higher-thrust engine with no more weight would be nice huh?


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## yulzari (Apr 12, 2013)

GregP said:


> Gimme' a Skyraider with modern avionics, a modern engine of 3,500 HP, and some smart weapons and I'll show you what an attack plane can do! I want the rotary cannons, too! No more rat-tat-tat ... more of a hummmmm ... and target gone. I'd rathre have a turboprop, but if that's out, a piston did just fine in the real beast, so it should do at least as well with a more reliable modern engine.



The snag is that, with the equivalent 3,500 bhp enemy fighter the Skyraider would last as long as a Fairey Battle in 1940 unless you had air supremacy. Witness the death of the dive bomber concept. However, another pair of threads.


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## Jabberwocky (Apr 12, 2013)

yulzari said:


> Perhaps a closer guide to the use of modern materials and technology is the Formula 1 engine. Simplisticly put, in @1970 it produced 400 bhp at 10k rpm. 40 years later it could put out 950 bhp at 20k rpm (rpm was then limited by the rules.).
> 
> This suggests that new materials and ignition control only increased the power from 13.33 bhp per litre per 1k rpm to 15.83 per litre per 1k rpm or barely 19%. The bulk of the total power increase came from the increase in rpm. As the late Keith Duckworth used to say; horsepower is the size of the bang multiplied by the number of bangs per minute.



F1 is not a good comparison, because the engine regulations are TIGHTLY controlled and you're comparing very different styles and size of engine.

A 3.0 liter, naturally aspirated Cosworth DFV in the early 1960s was producing a little over 400 hp at 75000 rpm. By the late 1970s it was producing 535 hp at 11,000 rpm, about 180 hp per liter of displacement.

Fast forward to the early-1980s and you get forced induction (turbocharged) engines. These producing about 800 hp from 1.5 liters, or about 535 hp per liter of displacement, for qualifying and about 720-740 hp for a 2 hour rance. By the end of the turbo-era in the mid 1980, the same 1.5 litre engines are producing 850-900 hp in race trim and over 1300 hp in qualifying trim, or about 865 hp per liter of displacement.

When F1 went back to natural induction, power dropped again. Still the 3 liter V10s were producing 890-930 hp in 2003/2004 at about 19500-19800 rpm, before the engine rpm restrictions. The Ferrari 053 was known to be making 920 hp at peak 19,500 rpm, the Mercedes FO 110 was producing about 910 and the Honda engine was suposed to be making 930 hp, possibly 950 hp in 2005.

Modern F1 engines, limited to 2.4 l and 18,000 rpm, produce about 765 to 780 hp. I've got a copy of a Mercedes dyno sheet showing 956 PS (940 hp) at 18,700 rpm.


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## GregP (Apr 12, 2013)

The original Skyraider would do just fine in any battleield where the opposition didn't have high-tech weapons ... which is MOST battlefields in an insurgency. For a declared war with defined lines ... maybe not. But anyone in Viet Nam who fired on a group of Skyraiders found out that the rest of the guys they didn't hit weren't very happy with them and rather quickly died.

I bet firing on a group of Su-25's produces the same result today unless you have whole s---load of Stingers and fire them all at once. Mostly, if you have these, the flyers will know and the Apaches will vists to reduce your inventory. If you do fire on a group of Su-25's, some Stingers will invariably lock onto the same target unless very well coordinated ... leaving the surviving Su-25's to be very angry with you. When that happens, you want to be anywhere else.

If it's too dangerous for Skyraiders, go visit with Reapers or other attack drones and THEN send in the Skyraiders. The people remaining will not be happy when they leave.


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## Milosh (Apr 12, 2013)

@ 1800rpm and -2lb boost the Merlin consumed 22gph
@ 2000rpm and -2lb boost it was 25gph

Spitfire VIII A58-315


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## Readie (Apr 12, 2013)

I agree about fuel injection and ECU's to get the most power for your bang as it were.
I wonder if the use of modern materials would give any significant weight loss?
So improving the power to weight ratio.
What do you guys think?
Cheers
John


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## dobbie (Apr 12, 2013)

If the engine controls go solid state, communications would follow along? That's going to save some weight and possibly shift weight to a more favorable balance. Getting rid of multiple magnetos and going to crank trigger ignition should save weight too-I'm not certain how distributorless ignition would function at high altitudes, but the only weight gain I can think of would be in the electrical system-higher output alternator/generators with which to power it all. 
Adding a rotary cannon is certainly going to add weight and complexity, with a speed penalty on single engine fighters because of where it would have to be mounted. One of the SUU pod setups did operate on a gas action but Im not certain how reliable it was. Wonder how effective a P38 with a 50 cal rotary in the nose might be for ground attack...


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## dobbie (Apr 12, 2013)

Readie said:


> I agree about fuel injection and ECU's to get the most power for your bang as it were.
> I wonder if the use of modern materials would give any significant weight loss?
> So improving the power to weight ratio.
> What do you guys think?
> ...



Oh, maybe a carbon fiber Mustang??? NICE!


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## nuuumannn (Apr 12, 2013)

> Oh, maybe a carbon fiber Mustang??? NICE!



There already is, the Thunder Mustang, a 3/4 scale one powered by a V-12 and its faster than the original! I've got pics of one somewhere...


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## GregP (Apr 12, 2013)

It is a lot of things, but it isn't faster than the original. They fly in the Reno Sport Class every year and lately had been turning slightly over 400 mph. Originals are faster and the dedicate racer P-51's are more than 100 mph faster.

Stevo Hinton has lapped Reno at 512 mph in Strega. More or less stock Mustangs in the Silver class have lapped at 445 mph or so.

The Thunder Mustang is really neat and I'd LOVE to fly one ... but it's a rich man's kitplane. I'm NOT fond of the Falconer V-12 made from a Jaguar V-12. It is pwoerful, but I've seen 3 let go all at once while racing and the result isn't pretty. The plane flies very well, though, as long as you are proficient in high-performance aircraft.

As an aside, Strega may never race again, but they made a one-piece carbon-fiber cowling and it SHOULD add some more speed to the 512 Stevo ran. Hope they get a chance to show it off. It would be a real shame if Strega never raced again ... but it may be in the cards mainly due to the cost of Reno racing. Nothing to do with not wanting to do so.


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## nuuumannn (Apr 12, 2013)

Hi Greg, well, there's a few areas where the original does outperform the Thunder Mustang, but not by much. Take a look at the specs on this page.

Blue Thunder Air Racing :: Specifications

We have one here, it is the fastest piston engined aircraft in the Southern Hemisphere. Looks real cool, despite the awful weather when I took these.


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## GregP (Apr 12, 2013)

Last time I flew in a Mustang we went up at 2,800 feet per minute at well less than full power, which we never used. Their specs are, shall we say, a bit optimistic.

Love the plane, but it does NOT out perform a Mustang except in rate of climb ... and not by anywhere NEAR the margin in the so-called specs at that. Seen too many of them not to know.

Still wish I had one ... with something other than the Falconer ... he makes a great engine technologically, but the Jaguar V-12 is not exactly a paragon of reliablity in a car much less a plane. Hell, I've only ridden in a Jag V-12 four times and have experienced one engine failure. Last Thunder Mustang crash I saw was a direct result of a blown Falconer V-12 and a 45 knot crosswind ... yeah ... he was going 400+ mph at the time of the failure, so the engien DOES make good power. 

The pilot didn't exactly handle the situation in a good manner, but I was impressed that he hit a berm while touchning down where he didn't want to and the gear didn't break off. Must be quite strong! The winner might have been another Thunder Mustang, but the race was called and the Gold Final was cancelled due to high wind.


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## wuzak (Apr 13, 2013)

The Falconer is not a Jag V-12 - it is based on the small block Chevy. So that means pushrod OHV.

The block is custom designed for the job.

Welcome to Ryan Falconer Racing Engines! - Falconer V12 FAQ

They use MoTeC fuel injection - an Australian company that supplies ECUs all over the world, including many motorsport series.


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## GregP (Apr 13, 2013)

When I last saw a Falconer up close, it still had the Jaguar logo and writing on it ... Maybe he makes something else today, but this was early in the Thunder Mustang days, and when Ryan was building Jags ... and ONLY Jags, for the Thunder Mustang. I haven't looked at his engines in 10 years or more, so you are probably correct. But he USED to build Jag V-12's, for the Thunder Mustang. 

I knew 3 people who died flying them, 2 in Arizona alone out of Scottsdale. I didn't like Jags much after that untl they started using engines associated with Ford. Ford might or might not be the best in the world, but they didn't fail nearly so often as the Jag V-12 did in everyday service.

I'll look up his website and see what is being built today out of curiosity ...


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## tyrodtom (Apr 13, 2013)

The Jaquar V12 in a 60 degree block overhead cam, the Falconar V12, is a 90 degree block, pushrod engine.
How could it possibly be based on the Jaquar ?


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## cherry blossom (Apr 13, 2013)

When we try to understand why we can get more power out of modern piston engines than WW2 engines of similar capacity, one reason is that we now know slightly more about what is happening inside the cylinders. Three terms that seem to inspire Google are “stratified charge” A textbook of automobile engineering - Rajput - Google Books, swirl and tumble ScienceDirect.com - Progress in Energy and Combustion Science - The effects of swirl and tumble on combustion in spark-ignition engines and http://iffc.cnrs.pprime.fr/slidesWkshp/Boree_IFFCWkshp2010_EIFpaper.pdf. Naturally, the gases were swirling during WW2 and it can be argued that sleeve valve engines gained from induction swirl http://www.enginehistory.org/members/articles/Sleeve.pdf and http://www.amazon.co.uk/dp/B0007JWELC/?tag=dcglabs-20. However, it is all better understood now. I suspect that an engine for a combat aircraft would gain more economy from stratified charge combustion than a modern car because there would be less concern about emissions.

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## GregP (Apr 13, 2013)

Hey Tyrodtom, 

When Ryan Falconer started building engines for the kit planes, he started out using Jaguar V-12's for some applications that wanted V-12's. As I stated just above, if he's building something else today then OK but, at one time, he had an engine based on the Jag unit and several folks at Scottsdale airport had them ... two that I know of came to grief flying the Jag-based units.

I see from the Falconer website his new engine is NOT a Jag unit and has a PSRU developed by an old aviation friend, B. J. Schramm (who founded Rotorway) along with Oswald Webb of Great Britain, now retired, who worked on the original Merlin reduction gears. Good for Ryan.

I also see the normally-aspirated unit develops 640 HP and the supercharged uunit belts out 1,200 HP and CAN be hopped up a bit from there. If they can get 1,500 HP from it then there is no reason the Thunder Mustang can't out-perform a real P-51 but the Thunder Mustang was designed to emulate a P-51 ... not a racer like Strega. If he developed an airframe tailored to racing specifically, then he might have something there that could rival the real thing. 

However most Thunder Mustang owners want a P-51-like airplane, not a dedicated racer. Racers make awful fun / transportation planes. They have as much equipment removed as possible, less fuel capacity, cooling capacity good for one race, etc. The Reno racer "Race 232," owned by Rod Lewis at present, started life as a Hawker Sea Fury FB.11, but is now a racer only. It can't really go more than about 250 miles before it has to land and top up the fuel and oil cooling system. If running at anything like high power, the ADI and spray bar won't even last for 6 laps at Reno. So if some Thunder Mustang owner wanted to race in the Unlimited Gold bracket, he might stand a chance, but faces some serious airframe modifications. They already KNOW what makes a P-51 go 500 mph and it COULD be done to a Thunder Mustang ... but that's not why you BUY a Thunder Mustang to start with. I'd expect 99%+ Thunder Mustangs to race in the Sport Class since they spend the other 51 weeks a year emulating a real Mustang. Neither Strega nor Voodoo have what could be called a P-51 airfoil anymore. Both have been "profiled." I don't know of anyone who would wanted to spend a lot of time and effort build the kit only to have to chop it up and alter the airfoil just for racing purposes ... but he might be out there somewhere. If so, I'd love to get involved and help!


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## Jack_Hill (Apr 13, 2013)

For a WWII a/c replica, an X48 based on the Suzuki 1000 Gsx-r group is, to me, an exciting idea, maybe unexpensive and powerfull.
Wonder if theorical performances could be achieved (2400 Hp and 144 M/Kg torque) with this atmo engine.
Wonder what turbocharging, common crankshaft, boost controls, electronic, final transmission... could add or take to outputs, wheight, reliability, fuel cunsumption an so on...
Wonder about cooling system (12 little coolers or a big common one)
In fact, wonders a lot about.
Could it be sound fitted into a modern, Al, Ti and carbon fiber new fighter or attacker concept ?


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## GregP (Apr 13, 2013)

What did he just say?


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## Jack_Hill (Apr 13, 2013)

Edited, Greg.
Hope clearer.


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## nuuumannn (Apr 13, 2013)

Greg, while I don't doubt your knowledge and exposure to the P-51 and Thunder Mustang, I just don't understand why these guys would put false information on their website. I've also talked to the engineer who maintains that one here in NZ and he also reiterates that it is faster than a P-51. There are two in this country, one of which is at the same airfield as the Thunder Mustang. The warbird community is small here and the number of P-51 drivers number a handful, and if these guys thought these Thunder Mustang guys were talking porkies, they'd say something. Its trumpeted at airshows that its faster. I just don't see why such a thing would be made up. But hey, stranger things have happened eh?

Saw one display to this track at an airshow. Very cool vid as well.


_View: https://www.youtube.com/watch?v=OKQyrL0doT4_


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## GregP (Apr 13, 2013)

Yeah Jack, that could be a very neat engine. A company like Suzuki, though, would have to see a market for teh product before jumping on board. A private development, ob the other hand. might be able to do it with the right backing. But youa re left with the nagging question, "What is the market so the development effort can pay for itself?"

Reno is sort of winding down and the really fast guys are retiring and their planes aren't being passed along to people whostill want to race just yet. Strega and Voodoo are the two fastest and neither one will be at Reno this year. Maybe if such an engine were developed, there would be some younger guns out there who want to race and have the money to do it. 

That would be the gamble in development of such an engine. They'd need a dedicated prop for htht power since the existing props taht can absorb such power are few and far between ... and likely already on an airplane somewhere.

Good luck! I'll watch for it.

Hi Nuuumannn, kitplane makers are always using the highest numbers they can get away with. It's nothing new. All race cars are faster in the story than on the track, too. I have no doubt at all teh Thunder Mustang will out-climb a real one ... it wasn't built for military use and the airframe is tailored for lightness and strength. It's a neat aircraft, but it isn't a warbird ... just looks like one. If you have some there going faster than the real ones, maybe your guys aren't pushing the real P-51's since engines are WAY expensive and propellers are almost non-existing these days. A quality overhaul on a Merlin will purchase a substantial portion of a completed Thunder Mustang.

Here in the USA, we have a 250 knot speed limit at 10,000 feet and below, and most warbirds here, regardlass of capability, usually cruise at 235 knots or below because the owners aren't interested in racing or IFR most of the time. They only fly them for fun on days of severe clear weather. Now, Rod Lewis is different. His airplanes are IFR capable and if he wants to use a warbird to go to a business meeting, he does.

So it is quite likely that a stock P-51D is about 370 mph at sea level on a Merlin if it has stock equipment only. If it has been "cleaned up" a bit, it is probably 385 - 390 mph at sea level. The Reno Thunder Mustang named "Blue Thunder" finished second in Sport Gold in 2012 at 377 mph. The winning Glassair III finished at 393 mph.

These are Reno racers and are not representative of tyeh usual kit Thunder Mustang. They have the money to run the high HP engines. Most Thunder Mustangs aren't running 1,200+ HP, but are pushing the 640 HP Falconer or possibly up to 800 HP. They won't beat a real P-51 and mostly aren't trying to do so. What they do is give the owner the joy of a Mustang at one-tenth the price of a real North American unit.

The Bronze Unlimited winner was Dan Vance in "Lady Jo" (the team owner is a good friend of the museum). He went 330 mph and wasn't pushing it. He bumped to Silver and only went 304 mph in the race becasue he was lapped by Steadfast going 394 mph. Why push your engine when the front runner is 100 mph faster? Steven Hinton qualified at 493 mph in the P-51D Strega and did a 512 mph lap. He won Gold at 477 mph and was pulling power off every 1 or two laps. The big secret to Reno success is to win as slowly as possible and save the engine. If you jump out to a big lead you back off 20 inches for a lap or two and then another 20 inches for another lap or two and make the guys behind you catch up. Hopefully they heat-soak their engines and have to back off. If they can't catch you, keep backing off and win as slowly as possible ... and maybe you can run the same engine NEXT year, too, without too much work on it.

Lady Jo is a two seater with a two seater canopy and only races for fun ... they try not to break anything, but they have a good time at Reno every year.


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## wuzak (Apr 13, 2013)

I don't think motorcycle engines would make a good basis for an aero engine. I think you would have far more reliability issues than with something based on the more solid car engine. 

48 is also a lot of cylinders. A lot of maintenance would be required. Also, how many cranks? How many units long?

I think you could make a 10l X-16 based on Ford V8 components. Modify a pair of heads for inverted operation. New crankcase and cylinder blocks, new crankshaft. Gear drive the DOHC system. Add supercharging, and away you go!


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## fastmongrel (Apr 13, 2013)

With modern techniques and materials I would be building a diesel aero engine. We had a car transporter in yesterday dropping off a pair of 2nd hand cars imported from Japan and I got chatting to the driver his vehicle had a 12 liter straight 6 with twin turbos that put out 600hp and used 21 litres per 100km. With that sort of economy you could send a Liberator off on Atlantic patrol and it wouldnt need to come back for 2 days


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## Balljoint (Apr 13, 2013)

The DB 60x had direct fuel injection as I recall. Being mechanical, it was a bit crude and tended to wash the cylinder walls a bit. But it did enhance power.

The issue of flame front travel in a large bore aircraft engine also has a modern answer. Cosworth developed swirl and tumble in the intake charge that, in conjunction with squish areas between the piston and cylinder head, generated intense turbulence in the fuel charge. Fuel burn is increased by the turbulence by around 15X. Perhaps greater in an ultra large bore. Judicious placement of duel ignition plugs could further enhance the burn rate.
The turbo compounded engines were probably the peak development of piston aero engines. But the turbine engine hot section was a better way of generating hot gases than the awkward reciprocating engine so turbo compounding was essentially stillborn.


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## Jack_Hill (Apr 13, 2013)

Greg : sure, Suzuki will never make it.
Only a private team of crazy guys could.
I know racers/replica building is a real tough job.
Warbirds and racers racing are parts of US culture, the lack of proper propellers available should alert some investors I think.

Wuzak :
Yes, a modern car engine base would be good.
Maybe better than a bike one.
And delivering more torque at lower rpm.

Concerning X48 :
Guess light overhauls : fluids dump, spark plugs replacement, filters etc... should occurs after about each 20/35 hours of heavy use (only deducted from a 200Km/h average from a standard 4 cylinders block bike to an estimed 300/ 400Km/h 48X a/c average) 
Overhauls, I don't know.
Correct me if needed, I think two cranks would be needed.
Unit lifetime could be long, due to natural ruggeness of this sound concept, but i can't give more precision. 

Again, just wondering.
Any more questions or contradictions welcomed.


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## tomo pauk (Apr 13, 2013)

Maybe the best candidate for the modern piston engine would be the turbocharged diesel?


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## Readie (Apr 13, 2013)

tomo pauk said:


> Maybe the best candidate for the modern piston engine would be the turbocharged diesel?



A high speed 2 stroke diesel?


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## CobberKane (Apr 13, 2013)

I believe Wankel auto engine are quite popular for use in kit aircraft. Nice and simple, with fewer reciprocating parts than a piston engine. Any design potential for the kind of outputs we are talking about?


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## wuzak (Apr 13, 2013)

CobberKane said:


> I believe Wankel auto engine are quite popular for use in kit aircraft. Nice and simple, with fewer reciprocating parts than a piston engine. Any design potential for the kind of outputs we are talking about?



Not sure how well they scale up.

They can be built in 3 and 4 rotor versions. More than that becomes complicated, unless you use multiple crankshafts joined together.

They do have a tendency towards heavy fuel consumption, however.


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## tyrodtom (Apr 13, 2013)

wuzak said:


> Not sure how well they scale up.
> 
> They can be built in 3 and 4 rotor versions. More than that becomes complicated, unless you use multiple crankshafts joined together.
> 
> They do have a tendency towards heavy fuel consumption, however.



I had a Mazda RX3 in the late 70's, it was fast, but it was the oil companies best friend. Oil and gas consumption was very high.


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## GregP (Apr 13, 2013)

The Mazda 3 rotor Wankel didn't ever run quite right for very long ... unlike the simple but small 12A and 13B engines. I've heard of a 4-rotor, but never anyting that suggested it was successful in other than a short race.

I'm not fond of diesels ... but also have never flown one, so I'll refrain from good or bad remarks until such time as I experience one ... or read about such an experience that doesn't somehow end in trouble, like the Thielert debacle.


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## nuuumannn (Apr 14, 2013)

High speed 2 stroke diesel? Napier Nomad!


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## wuzak (Apr 14, 2013)

GregP said:


> The Mazda 3 rotor Wankel didn't ever run quite right for very long ... unlike the simple but small 12A and 13B engines. I've heard of a 4-rotor, but never anyting that suggested it was successful in other than a short race.



Mazda won Le Mans with a 4 rotor Wankel in 1991.

Mazda 787B - Wikipedia, the free encyclopedia


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## MikeGazdik (Apr 14, 2013)

I remember when I first saw a cut-away Rolls Royce Merlin. Roller cams, lifters, and knife edged cranks. Stuff that only race cars used in the 1980's, 40 years later. 

In the USA, the old V8 "muscle car" engines are still the main source of race engines in circle track and drag racing. I know road racing has other favorites. Just looking at the V8 engine in the USA. Since the late 80's in the racing world, I think the 2 major increases in power has been cylinder head development and fuel management. 

I wonder how much power an unlimited Rolls or Allison could make if a completely new cylinder head was made that could be bolted on to existing blocks could be made? The modern engines using digital fuel management are also increasing the horsepower and dependability of race engines. And compared to the times of WWII, the oil technology and bearing material has increased the life of an engine.

I could see a "vintage" 1650 cubic inch Merlin, with modern improvements, making 3000hp reliably.


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## wuzak (Apr 14, 2013)

MikeGazdik said:


> I remember when I first saw a cut-away Rolls Royce Merlin. Roller cams, lifters, and knife edged cranks. Stuff that only race cars used in the 1980's, 40 years later.



Rolls-Royce Merlins didn't have "roller cams".

No lifters either.

Not sure they had knife edge cranks, but then I am not sure what they are!


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## wuzak (Apr 14, 2013)

See, no lifters or rollers.


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## Glider (Apr 14, 2013)

The Merlin maxed out at around 2,200hp but I do agree that with modern metals, fuels and management systems a reliable 3,000hp is more than possible.


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## wuzak (Apr 14, 2013)

Glider said:


> The Merlin maxed out at around 2,200hp but I do agree that with modern metals, fuels and management systems a reliable 3,000hp is more than possible.



RM.17SM - 2620hp @ 3150rpm, +36psi boost, ADI, special fuel.
2380hp @ 3300rpm, +30psi boost in an accidental 15 minute run.

Eventually rated for 2200hp. It certainly shows that more was possible, especially if it was allowed to rev more.


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## MikeGazdik (Apr 14, 2013)

Maybe it was an Allison??? Could of swore I saw roller lifters or rockers????? puzzled.


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## Glider (Apr 14, 2013)

We tend to look at the power but I would expect the engine to weigh a lot less than the originals. Modern engines rev at extrordinary speeds compared to the engines of old plus the adjustable valve technology and electronic systems allow for considerable improvements in performance.


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## Shortround6 (Apr 14, 2013)

Something to consider is that NOT all automotive engine technology could or would be transferred. 

You do want to keep the aircraft engine as simple as possible. 

Aircraft engines have one MAJOR difference from car and motorcycle engines. 

There _is/are NO_ artificial constraints on the engine size/displacement. 
1. There are no taxes based on the size of the engine at time of purchase or on an annual basis.
2. There are no licencing or user restrictions based on engines size.
3. There are no 'racing' rules that limit displacement to certain sizes.

Aircraft engines are pretty much limited by two things.
1. Cost to manufacture/overhaul. 
2. Power to weight ratio. 

A large but light, slow revving engine may be preferable to a small but heavy 'buzz-bomb' engine. 

Especially at overhaul time


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## wuzak (Apr 14, 2013)

MikeGazdik said:


> Maybe it was an Allison??? Could of swore I saw roller lifters or rockers????? puzzled.



Allison does have rollers. Not sure about lifters - Greg could help with the answer to that.


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## GregP (Apr 14, 2013)

The Allison has roller rockers and no lifters. The springs do it for lift and the pivoting clearance adjusters sit on top of the valve stem. The 12-counterweight crankshaft will handle 3600 rpm (cleared) and 4000 rpm (design speed). The tractor pullers Joe builds Allisons for in Europe today turn it at 4500 rpm and haven't broken an engine in years.

The 4-rotor wankel in the Mazda finished well down in the season, 9th and 10th in your post, so I discount it pretty much as generally not successful. A LOT of development and 1 major win (forgot about that one at Le Mans) is not a great advertisement for the engine in an aerial application. If the engine fails on an automotive race track, you can pull over and park. In an aircraft it is a life-threatening event, espccially in a military fighter aircraft which have never been noted as good gliders.


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## nuuumannn (Apr 15, 2013)

Nice one Shortround. Interesting that horizontally opposed engines in light aircraft are little more complex than they were when they first came out. A true example of the saying If it ain't broke, don't fix it, if ever there was one. Greg, thanks for the explanation, I'd love to go to Reno one day!


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## CobberKane (Apr 15, 2013)

You have to hand it to the reciprocating piston engine, it's seen off all alternatives over the years, including the rotary. Inevitably something will come along and knock it off it's perch but there doesn't seem any sign of it yet


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## Shortround6 (Apr 15, 2013)

Flat six air-cooled engines went through an interesting period back in the 1950s. Lycoming got a number of their engines up to 3400rpm using an 0.64:1 reduction gear (2176 prop rpm?) and put mechanical superchargers on the two biggest.
The six cylinder GSO-480 (480 cu in) gave 340hp max from sea level to 8,000ft at 3400rpm using 9lb of boost and could 'cruise' giving 240hp at 11,500ft at and weighed 498lbs.
The eight cylinder GSO-580 (580 cu in) gave 380hp max at sea level at 3300rpm using 5.8lb of boost and weighed 610lbs.

they were replaced by engines using larger cylinders. 
The six cylinder IO-480 (540 cu in) gave 290hp max sea level at 2575rpm for 437lbs. 
The eight cylinder IO-720 (720 cu in) gave 400hp max at sea level at 2650rpm and weighed 600lbs.

There were some more complicated geared and supercharged engines but most (all?) of them gave way to the gas turbine engines. 

Something else to consider is the duty cycle. These aircraft engines were expected to cruise at 250-300hp for hours on end and last hundreds of hours between overhauls. the unsupercharged ungeared ones were supposed to go closer to 2000 hours than 1000 hours unless being used for crop duster duties.
Modern car and motorcycle engines spend an awful lot of their time at 20-30% of full power ( some powerful sport engines spend even less, how much power does a Porsche need to cruise at 60mph on the high way?) or how much power does a 1000cc motorcycle engine use to do the same thing? 

Modern materials and modern technology can make a difference in aircraft engines, just don't expect quite the the same amount of improvement as car or motorcycle engines.

Also comparing unsupercharged engines to supercharged ones gets a little strange. Trying to design/build a modern Merlin to wind hundreds of RPM higher may work, especially now that you can't get the fuel it ran on but the old engines operated over a narrow rpm band ( 2 to 1?) and varied the amount of boost to vary the power (amount of air flowing through the engine). Modern unsupercharged engines operate at a near constant "boost" (actually negative or a partial vacuum) and vary the rpm (5 to 1 or even 10 to 1) to vary the power (amount of air flowing through the engine).


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## gumbyk (Apr 15, 2013)

> Modern unsupercharged engines operate at a near constant "boost" (actually negative or a partial vacuum) and vary the rpm (5 to 1 or even 10 to 1) to vary the power (amount of air flowing through the engine).



Modern aircraft engines still operate at a near constant RPM (or a very narrow band) and vary the manifold pressure (boost) to vary power.
E.G. you may take-off at max throttle and RPM (29" MP, and 2800 RPM)
Climb at max continuous (25" MP and 2500 RPM)
Cruise (23" MP and 2400 RPM)
Approach (15" MP and 2400 RPM)

Of course, if you're talking car/motorcycle engines, then you can't vary one without altering the other.


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## OldSkeptic (May 1, 2013)

wuzak said:


> RM.17SM - 2620hp @ 3150rpm, +36psi boost, ADI, special fuel.
> 2380hp @ 3300rpm, +30psi boost in an accidental 15 minute run.
> 
> Eventually rated for 2200hp. It certainly shows that more was possible, especially if it was allowed to rev more.



Beat me to it. Type approved for production as well..
2,400bhp+ for the RM17SM was quite possible for production, even more. With modern technology, particularly modern oils, 2,600-2,800 (with water injection) should be possible.

The 'forgotten factor' oils, what they could have done with our high temp multigrade oils. At the time it was a major limiting factor in performance, particularly continuous performance.

Apart from that maybe a little (for the Merlin) more revs. But that is a piston speed and flame propagation limit. And really we can't improve much on the materials they used at the time. Heck they still use some of the RR alloys today in areas like Formula 1.

Computerised control systems could have optimised performance, particularly things like cruise economy, perhaps even short burst maximum power by super over riching (as per the C3 system used by the Germans).

Things like variable vane super/turbo chargers (actually trialled by the Germans from memory) could have helped, especially with the computerised control systems. Not sure you'd be able to get much more maximum power, but you could get better power/economy at cruise speed.

So overall I'm not sure, at least for operational purposes (Reno racers don't count) you could get a lot more power, a not insignificant bit more of course, but my gut feel that the real winners would be in areas like cruise efficiency.


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## swampyankee (Aug 13, 2018)

One can see a hint how modern fighter piston engines could go by looking at something like NASA's GAP program in the early 1980s, where the concentration went pretty quickly to highly supercharged two-stroke diesels with no mechanical driven scavenge pump. Another hint would be the Napier Nomad.

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## Jugman (Aug 14, 2018)

swampyankee said:


> One can see a hint how modern fighter piston engines could go by looking at something like NASA's GAP program in the early 1980s, where the concentration went pretty quickly to highly supercharged two-stroke diesels with no mechanical driven scavenge pump. Another hint would be the Napier Nomad.



Two-stroke diesels with the required power density are just not possible. They suffer from a number of problems that are insurmountable. Proper lubrication and side port erosion are the two I recall. In any event you can actually equal the power density of a two stroke with a good turbocharged four stroke. This is something EMD has discovered the hard.


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## swampyankee (Aug 14, 2018)

Jugman said:


> Two-stroke disels



Ayuh

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## Shortround6 (Aug 14, 2018)

Diesels may be the only route as such concoctions as 108/135 and 115/145 are thing of the past for a number of reasons, two of which are cost and safety in handling. OSHA would have conniptions if anyone tried to introduce those old fuels again with some of their toxic components.

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## GrauGeist (Aug 15, 2018)

Not to mention the fact that diesel fuel congeals at higher altitudes...


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## Shortround6 (Aug 15, 2018)

Could try running the diesels on jet fuel.

Edit> I would note the Germans flew diesel powered aircraft at 40,000ft or above during WW II so it doesn't seem that diesel fuel congealing is an insurmountable problem.

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## swampyankee (Aug 15, 2018)

Shortround6 said:


> Diesels may be the only route as such concoctions as 108/135 and 115/145 are thing of the past for a number of reasons, two of which are cost and safety in handling. OSHA would have conniptions if anyone tried to introduce those old fuels again with some of their toxic components.



...and the whole endemic neurological damage due to lead poisoning.


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## Shortround6 (Aug 15, 2018)

I am not sure that some of the aromatic compounds were any less dangerous (Benzine?) , not to say there aren't some carcinogenic compounds in diesel exhaust.

The high octane/performance number fuels of the last part of WW II and during the 40s and 50s required a disproportionate amount of crude oil/base stock. You got much fewer gallons of high performance fuel per barrel of crude oil/base stock than for lower grades of fuel. They also required much more elaborate refinery set-ups and often large quantities of materials from the chemical industry.

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## swampyankee (Aug 15, 2018)

Shortround6 said:


> I am not sure that some of the aromatic compounds were any less dangerous (Benzine?) , not to say there aren't some carcinogenic compounds in diesel exhaust.
> 
> The high octane/performance number fuels of the last part of WW II and during the 40s and 50s required a disproportionate amount of crude oil/base stock. You got much fewer gallons of high performance fuel per barrel of crude oil/base stock than for lower grades of fuel. They also required much more elaborate refinery set-ups and often large quantities of materials from the chemical industry.



Somewhat relatedly, there have been significant problems with lack of restrictions on contaminants like sulfur in road fuels, such as US gasoline in the past (much less so now) and US diesel; the former caused problems with auto engines using Nikasil cylinders and the latter largely precluding high-performance diesels.

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## MACHIA (Aug 24, 2018)

dobbie said:


> Nothing really wrong with the WWII designs per se-they are sound designs even for today. The increased capability would be mostly centered around the use of better/lighter/stronger alloys which would allow higher continuous RPMs from lower rotating mass, computer controlled ignition and direct injection systems and much improved supercharging.


Agree .


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