WI: NACA Modified P-38

[EverKing]

The detachable wing tips seem like a good idea in theory but how practical that would prove in the field may depend on how fragile they are when stored and how easily they can be swapped. Perhaps flight testing may show little gain using the short clipped tips.

The construction of the tip is actually the same as in the P-38 (although in this case the tip chord is 42" instead of 36") and will be plenty strong. Also, remember that they designed the "long" tip to hold a 1000# of stores, so it is reinforced and plenty strong. With that in mind, I would also like to point out that this is simply the initial design. I image that by the time it goes into active service or shortly thereafter, likely around 1947-48 or so, both tips will probably be abandoned in favor of a (as-yet un-designed or even imagined) superior tip-tank a la T-33. A proper tip tank like that will produce an end-plate effect providing a virtual increase in Aspect Ratio without the added stress and drag of increasing span. The effect isn't really known (or at least not well known yet) in 1944 so it will be a few years before we see it.

And ofcourse the P-81 will retain the hydraulic aileron boost.

Of course! In fact, the P-81 will apply all of the advanced tech found in the P-38 and then some. Boosted ailerons, Dive Recover Flaps, Lockheed-Type Fowler Flaps, and sunken leading edge radiators all in a newly designed NACA 6-Series laminar flow wing, plus Handley-Page (automatic, pressure controlled) leading edge slats, multiple hardpoints, and a new self-sealing "wet wing" for increased fuel capacity. And that is just the wing! In addition, it will have the Lockheed style throttle controls from the P-38J/K, and Allison will improve the Unit Engine Control concept to incorporate all of the interlink automatically at the engine (rather than having that cludgey Rube-Goldberg mechanical UEC in the cockpit) much as they did with their later G-series engines as found in the OTL P-82. I would think that by 1950 (likely earlier) it will be fitted with the USAF standard fighter stick with electric trim control, etc. Also, there is the possibility of fitting a radar gunsight in the 1950's and beyond. I can see the F-81 becoming a USAF test bed for RADARs and for the early Air-to-Air Missiles, although I doubt it will ever use them operationally. All of this will come in time.

That's a beaut.

Thank you! I am rather fond of it.

I have only one tiny esthetic gripe: the canopy flattening.

Yeah, I wasn't a big fan either, but it seemed the simplest solution. Also, I have to remind myself they it is a three-dimension curved surface, so even though it looks flat it is actually curved and only the terminus is a straight line--think of it like the booms, they look flat in the side-view but we know they really aren't.

One thing I wondered: is it possible the armament fit might be adapted to later marks of P-38?

The P-38's nose is a bit more cramped (see the comparison drawing in that last chapter to get an idea of the size difference in the nose) and really the 4 x AN/M2 w/ 500 rpg and 1 x A/N-M2C w/ 150 rpg is about the limit of what they can fit in there. IOTL there was an experimental 8 x .50 set up (which was also fitted with dual .50 gun pods on each outer wing hard point for a total of 12 x AN/M2 HMGs) so it is possible to squeeze more in there. I do no have any information on how much ammunition it carried with his configuration but I would image a reduction to 350 rpg or so just from looking at the limited space.

The P-81 can hold a lot more with little difficulty, though.

 

[phx1138]

Yeah, I wasn't a big fan either, but it seemed the simplest solution. Also, I have to remind myself they it is a three-dimension curved surface, so even though it looks flat it is actually curved and only the terminus is a straight line--think of it like the booms, they look flat in the side-view but we know they really aren't.

Yeah, it's a complex curve in 3-D. Doesn't mean the drawing doesn't still look wrong.

The P-38's nose is a bit more cramped (see the comparison drawing in that last chapter to get an idea of the size difference in the nose) and really the 4 x AN/M2 w/ 500 rpg and 1 x A/N-M2C w/ 150 rpg is about the limit of what they can fit in there. IOTL there was an experimental 8 x .50 set up (which was also fitted with dual .50 gun pods on each outer wing hard point for a total of 12 x AN/M2 HMGs) so it is possible to squeeze more in there. I do no have any information on how much ammunition it carried with his configuration but I would image a reduction to 350 rpg or so just from looking at the limited space.

That's another one of those overkill ideas that appeal to modellers & customizers. If the Germans might last a bit longer, or if there was a WW3, it might be sensible to do it, but otherwise, not necessary.

Thx for taking the trouble to consider it.

 

[sonofpegasus]

Some marks of the Spitfire had extended wing tips for increased high altitude performance and of course others had their wing tips clipped for a better roll rate. So these proposed mods are not without precedence.

 

[Warden]

11 July 1944
Total possible fuel capacity then—with 500 gallons internal, two 310 gallon tanks on the main racks, and two 165 gallon tanks at the wingtips—would be as much as 1,450 Gallons and a theoretical range of at least 5000 miles.

Dear lord, that's insane... For reference that's further than New York to Moscow or Oregon to Tokyo. If we assume that will allow a 1500 miles combat radius that is sufficient to reach Moscow!!! from eastern England or Kyoto from Luzon.

 

[EverKing]

Woot! I found a complete (1948) NACA report on their testing a (single-stage) Turbo-Compound V-1710 with comparisons to a non-compound Turbosupercharged V-1710, and several other variations. This could just be the mother load I need to finalize my ultimate V-1710 version for the P-81...now, to digest it.

EDIT: And a followup report!
EDIT 2: a key sentence just jumped out at me from the first report (emphasis added)...

At an altitude of 35,000 feet, the compound engine operated at best-power Pe/Pm [ed. Exhaust Pressure:Manifold Pressure ratio] produces 21 percent more power than the turbosupercharged engine with 23 percent lower specific fuel consumption.

EDIT 3: So, the first one is of a different type of Compound engine using. The second report (I'm still reading through it) appears to be more applicable to our purposes. More to follow...
EDIT 4: Yes, the first report and several of the options show in the second use a "Steady flow turbine" which provides supplementary jet propulsion to the system. However, there is plenty of good data that when combined with the (long-ago) previously mentioned NACA Report 786 (cited in these report as a matter of fact) I can get some numbers and power curves put together.

 

[EverKing]

Dear lord, that's insane... For reference that's further than New York to Moscow or Oregon to Tokyo. If we assume that will allow a 1500 miles combat radius that is sufficient to reach Moscow!!! from eastern England or Kyoto from Luzon.

That's the intent of the USAAF VLR Escort program. They wanted fighters that could escort B-29s (and later B-36s) over enemy territory. This is very close to the OTL range of the P-82B...but this projected ATL P-81 can do it with less fuel burn thanks to the Turbo-Compound/Turbocharged engines.

 

[sonofpegasus]

EverKing your ability to find technical obscurities and develop them into a plausible progressive aircraft development is nerdish to a truly awe-inspiring magnitude. This thread has been an complete tour de force and I have to absolutely applaud your writing and research.

 

[tomo pauk]

What is said in the above post.

 

[EverKing]

EverKing your ability to find technical obscurities and develop them into a plausible progressive aircraft development is nerdish to a truly awe-inspiring magnitude. This thread has been an complete tour de force and I have to absolutely applaud your writing and research.

Thank you, sonofpegasus. I like the research, mainly because I like learning. When I was younger I had inherited the full set of 1963 World Book Encyclopedia (plus their "Year Books" up to 1988) and would often while away the hours pouring through them or any of my other miscellaneous reference and technical books. The invention of the World Wide Web and later improvement of search indices has been my life-blood ever since. I guess I have developed a talent for finding information because of this.

For those who may want to find more, there are about 1 million NACA/NASA documents available at: https://ntrs.nasa.gov/search.jsp. It is a veritable treasure trove of great information.

 

[Draconis]

It's great to see the turbo-compound engines getting a bit more of that alt-history love. They were in real life just a brief and minor transitory stage between the piston and the jet engine. But there was a missed opportunity in the late 1930s to mid 1940s to get more power and range out of the large piston engines used by military aircraft before the arrival of the jet engines. Well, that's what alt-history is for. Especially when it's done in EverKing's well written and well thought out manner.

 

[phx1138]

produces 21 percent more power than the turbosupercharged engine with 23 percent lower specific fuel consumption.

I thought that was impossible.

That suggests really good things for bomber escort in PTO late in the war (presuming it happens in time...)

Long range on the P-81 could change the development of jet fighters a bit, & maybe tankers, too, provided the P-81's performance against jets isn't too deficient. It might push USAF toward bigger, longer-legged jets...& with more turbocompounding earlier, it might be possible to reduce the "thirstiness" & improve power enough to make it credible. It might also change the operating characteristics: faster turbine response might mean the A-4 technique (using speed brakes rather than throttle) doesn't happen.

Thx for the links, btw, but can you post the titles? I"m getting "connection error" on both links (as usual... I've got a browser so out of date & idiosyncratic, it's like an episode of "Outer Limits".)

EverKing your ability to find technical obscurities and develop them into a plausible progressive aircraft development is nerdish to a truly awe-inspiring magnitude. This thread has been an complete tour de force and I have to absolutely applaud your writing and research.

Amen & squared. I wish I'd said it.

It's great to see the turbo-compound engines getting a bit more of that alt-history love. They were in real life just a brief and minor transitory stage between the piston and the jet engine. But there was a missed opportunity in the late 1930s to mid 1940s to get more power and range out of the large piston engines used by military aircraft before the arrival of the jet engines. Well, that's what alt-history is for. Especially when it's done in EverKing's well written and well thought out manner.

Agreed.

The increased success TTL makes me think: could it become more popular TTL as a result? Not just airliners, which I'd expect to use *R3350s or TC *R4360s, but even general aviation? Like TCs instead of (before) PT-6s in King Airs & such. I hesitate to suggest it in 172s, but a less-thirsty, more powerful engine is always a good thing. It might percolate down to homebuilts, too. Picture a T-18 or VariEze with a 200hp TC. Maybe it's enough to make the BD-5 a success?

And maybe it impacts hot rodders, too. Say, TCd nitro cars at the first NHRA Nats in '55?

I wouldn't expect EverKing to tell us about that in-TL, 'cause that would need enormous research. I do wonder what he thinks, tho.

 

[EverKing]

I thought that was impossible.

Well, that particular engine was set up not with a blowdown compound but with a "steady flow turbine" compound--essentially a single stage jet adding additional thrust to the exhaust (they even went on to experiment with afterburning using a 1.0 exhaust pressure:intake pressure ratio with positive results). As such, it would be expected (knowing what we now know about increasing turbine efficiency over altitude) that it would be more powerful and efficient at and above the tropopause. I do know that Pratt and Whitney developed a version of the R-4360 around this idea (the R-4360-51 VDT--"Variable Discharge Turbine" using an adjustable exhaust nozzle) for the B-36 and tested in a B-50, irrc. They were never able to work out the control systems for the engine, though, and abandoned it as the new generation of all jet bombers started coming out.

Thx for the links, btw, but can you post the titles?

1. NACA-TR-786, "Performance of Blowdown Turbine Driven by Exhaust Gas of Nine-Cylinder Radial Engine" (this is the original Turbo-Compound test and the one mentioned in the TL Narrative).
2. NACA-TN-1602, "Calculated performance of 12-cylinder liquid-cooled engine with exhaust-gas turbine geared to crankshaft"
3. NACA-TN-1735, "Performance of Exhaust-gas Blowdown Turbine and Various Engine Systems Using a 12-cylinder Liquid-cooled Engine"

A complete index (by subject/category) of all NACA reports from 1915-1949 can be found by searching "Index of NACA Technical Publications: 1915-1949" on the This Site. I think you will find many interesting papers in there that will be right up your alley (e.g. regarding the effects of exhaust back pressure on an engine, or regarding changing mixture in a supercharged engine, etc.).

The increased success TTL makes me think: could it become more popular TTL as a result?
...
I wouldn't expect EverKing to tell us about that in-TL, 'cause that would need enormous research. I do wonder what he thinks, tho.

I think its increased popularity and development ITTL will be entirely dependent on Allison getting it to work properly and reliably in our P-81. Just having an air frame for the engine, though, is a huge step forward vs. OTL as it guarantees at least least some R&D money from Uncle Sam and the pressure of keeping the research going instead of just dropping to work exclusively on Gas Turbines (turbojet and turboprop). Assuming they get the kinks worked out and are able to achieve even half of the expected performance and efficiency gains I think the Turbo-Compounding may have a pretty good future ITTL. It will likely delay operational introduction of some early turboprops and I would think the Civilian market will continue to use many TCs on to the modern era. It has a few advantages over even modern props, especially for civilians and bush pilots--mainly, the availability of fuel. Pretty much all airports with fuel service will offer 100LL AvGas but many do not offer Jet A or Jet B. This means that high performance, low burn, aircraft (such as your King Air) can be built with TCs and be able to service more locations. For Beech, I would think they would most likely end up with the Queen Air being TC and the King Air still be Turboprop. Also, machines like the DH Beaver, Otter, and Twin Otter will most likely have TC options for these same reasons--better performance over the base engine but still able to use standard fuels. I think that would be highly desirable in A/C operating out of remote locations where Jet A is probably not very common. Plus, when you're flying over the remote Canadian territories you want as much endurance as possible and a properly developed and reliable TC can get that for you.

In the "ground" market, I think the first applications (apart from some hot-rodders, like you said) would be in shipping, fleet, and farm vehicles where fuel use, even as early as the 50's or 60's, can have a pretty large impact on the bottom line. After that, the energy crisis of the '70's would possibly motivate passenger vehicle manufacturers to pursue TC with a partial introduction in the late '70s or early 80s followed by a more complete fleet-wide application after the 2008 collapse (much as we've seen the dramatic increase of hybrid and turbocharged vehicles). An interesting side effect of all this could be a reduction of global fossil fuel use and emissions over these past 40-50 years--I wonder how much an impact that would have on other factors (climate, economy, development of electric vehicles, etc.)?

 

[Butchpfd]

Well, that particular engine was set up not with a blowdown compound but with a "steady flow turbine" compound--essentially a single stage jet adding additional thrust to the exhaust (they even went on to experiment with afterburning using a 1.0 exhaust pressure:intake pressure ratio with positive results). As such, it would be expected (knowing what we now know about increasing turbine efficiency over altitude) that it would be more powerful and efficient at and above the tropopause. I do know that Pratt and Whitney developed a version of the R-4360 around this idea (the R-4360-51 VDT--"Variable Discharge Turbine" using an adjustable exhaust nozzle) for the B-36 and tested in a B-50, irrc. They were never able to work out the control systems for the engine, though, and abandoned it as the new generation of all jet bombers started coming out.

1. NACA-TR-786, "Performance of Blowdown Turbine Driven by Exhaust Gas of Nine-Cylinder Radial Engine" (this is the original Turbo-Compound test and the one mentioned in the TL Narrative).
2. NACA-TN-1602, "Calculated performance of 12-cylinder liquid-cooled engine with exhaust-gas turbine geared to crankshaft"
3. NACA-TN-1735, "Performance of Exhaust-gas Blowdown Turbine and Various Engine Systems Using a 12-cylinder Liquid-cooled Engine"

A complete index (by subject/category) of all NACA reports from 1915-1949 can be found by searching "Index of NACA Technical Publications: 1915-1949" on the This Site. I think you will find many interesting papers in there that will be right up your alley (e.g. regarding the effects of exhaust back pressure on an engine, or regarding changing mixture in a supercharged engine, etc.).


I think its increased popularity and development ITTL will be entirely dependent on Allison getting it to work properly and reliably in our P-81. Just having an air frame for the engine, though, is a huge step forward vs. OTL as it guarantees at least least some R&D money from Uncle Sam and the pressure of keeping the research going instead of just dropping to work exclusively on Gas Turbines (turbojet and turboprop). Assuming they get the kinks worked out and are able to achieve even half of the expected performance and efficiency gains I think the Turbo-Compounding may have a pretty good future ITTL. It will likely delay operational introduction of some early turboprops and I would think the Civilian market will continue to use many TCs on to the modern era. It has a few advantages over even modern props, especially for civilians and bush pilots--mainly, the availability of fuel. Pretty much all airports with fuel service will offer 100LL AvGas but many do not offer Jet A or Jet B. This means that high performance, low burn, aircraft (such as your King Air) can be built with TCs and be able to service more locations. For Beech, I would think they would most likely end up with the Queen Air being TC and the King Air still be Turboprop. Also, machines like the DH Beaver, Otter, and Twin Otter will most likely have TC options for these same reasons--better performance over the base engine but still able to use standard fuels. I think that would be highly desirable in A/C operating out of remote locations where Jet A is probably not very common. Plus, when you're flying over the remote Canadian territories you want as much endurance as possible and a properly developed and reliable TC can get that for you.

In the "ground" market, I think the first applications (apart from some hot-rodders, like you said) would be in shipping, fleet, and farm vehicles where fuel use, even as early as the 50's or 60's, can have a pretty large impact on the bottom line. After that, the energy crisis of the '70's would possibly motivate passenger vehicle manufacturers to pursue TC with a partial introduction in the late '70s or early 80s followed by a more complete fleet-wide application after the 2008 collapse (much as we've seen the dramatic increase of hybrid and turbocharged vehicles). An interesting side effect of all this could be a reduction of global fossil fuel use and emissions over these past 40-50 years--I wonder how much an impact that would have on other factors (climate, economy, development of electric vehicles, etc.)?

Everking, you just keep it coming with great ideas based on this line of tech boosts. My granddad and his buddies ( who all stayed avation enthuasists) and were EAA members post war would be in tech heaven!

 

[EverKing]

Here's another interesting tidbit from the first document (NACA-TN-1602, the one with the steady flow compound engine compared to a turbosupercharged one): they also tested both setups (stead flow compound and turbo-S/C) without the engine-driven S/C stage. Here's the results for the turbo engine (note, this engine DOES NOT use any compounding, but is strictly a turbo-S/C as found on the P-38):

The computed performance of the modified engine is better...because: (1) aftercooling provides more reduction of the engine inlet-manifold temperature than intercooling and (2) a higher efficiency (80 percent) was assumed for the turbine-driven supercharger than was obtained from the relatively inefficient fixed engine-stage supercharger. In addition, the modified engine does not introduce the throttling losses incurred by the original engine system at low altitudes.
...
The increase in net thrust horsepower of the modified turbosurpercharged engine resulting when altitude is increased from sea level to 28,000 feet (approximately maximum-power altitude) is about 16 percent with a corresponding decrease in specific fuel consumption of about 10 percent.
...
At an altitude of 28,000 feet, the turbosupercharged engine of the modified system produces about 27 percent higher net thrust horsepower than the turbosupercharged engine of the original (two supercharger) system with a corresponding reduction of 18 percent in specific fuel consumption. The improvement in the turbosupercharged engine performance with change from the original to the modified system is large because in addition to the aforementioned advantages obtainable by modifying the system: (1) removal of the engine-stage supercharger shifts this load from the engine to the turbine thus making greater use of the turbine work available in the exhaust gas, and (2) increasing the inlet pressure to the exhaust nozzle to the value corresponding to maximum net power produces considerable exhaust-jet thrust.

Of course, in order for a P-38 (or P-81) to use the exhaust-jet thrust we will have to redesign the exhaust outlet and wastegate; but, I think it should be possible. What this means is that even without turbo-compounding we can gain a mean of 16% thrust and a 10% nsfc reduction in our existing airplane. Assuming they realize this and give it a try ITTL prior to war's-end.

 

[phx1138]

they even went on to experiment with afterburning

That's either crazy or brilliant. I'd love to know what it looked like when it was used (if it ever was). And I have to wonder what the nacelles would be made from if it was!

the R-4360-51 VDT--"Variable Discharge Turbine" using an adjustable exhaust nozzle) for the B-36 and tested in a B-50, irrc. They were never able to work out the control systems for the engine, though, and abandoned it as the new generation of all jet bombers started coming out.

That's really the trouble for all of this: it needed to start in 1935, not 1945...

1. NACA-TR-786, "Performance of Blowdown Turbine Driven by Exhaust Gas of Nine-Cylinder Radial Engine" (this is the original Turbo-Compound test and the one mentioned in the TL Narrative).
2. NACA-TN-1602, "Calculated performance of 12-cylinder liquid-cooled engine with exhaust-gas turbine geared to crankshaft"
3. NACA-TN-1735, "Performance of Exhaust-gas Blowdown Turbine and Various Engine Systems Using a 12-cylinder Liquid-cooled Engine"

I managed to find them here, so thx for that.

I think its increased popularity and development ITTL will be entirely dependent on Allison getting it to work properly

Yeah, given it's going to be used in airliners or somewhere.

I think the Turbo-Compounding may have a pretty good future ITTL. It will likely delay operational introduction of some early turboprops and I would think the Civilian market will continue to use many TCs on to the modern era. It has a few advantages over even modern props, especially for civilians and bush pilots--mainly, the availability of fuel. Pretty much all airports with fuel service will offer 100LL AvGas but many do not offer Jet A or Jet B. This means that high performance, low burn, aircraft (such as your King Air) can be built with TCs and be able to service more locations. For Beech, I would think they would most likely end up with the Queen Air being TC and the King Air still be Turboprop. Also, machines like the DH Beaver, Otter, and Twin Otter will most likely have TC options for these same reasons--better performance over the base engine but still able to use standard fuels. I think that would be highly desirable in A/C operating out of remote locations where Jet A is probably not very common. Plus, when you're flying over the remote Canadian territories you want as much endurance as possible and a properly developed and reliable TC can get that for you.

I was thinking much the same. The drawback is the cost of avgas over Jet-A (which I'd overlooked, before...). Between that and more maintenance required (against turbines), TC might not be competitive anyhow. I won't begin to guess what the breakeven point between higher fuel/maintenance and lower fuel burn is.

In the "ground" market, I think the first applications (apart from some hot-rodders, like you said) would be in shipping, fleet, and farm vehicles where fuel use, even as early as the 50's or 60's, can have a pretty large impact on the bottom line. After that, the energy crisis of the '70's would possibly motivate passenger vehicle manufacturers to pursue TC with a partial introduction in the late '70s or early 80s followed by a more complete fleet-wide application after the 2008 collapse (much as we've seen the dramatic increase of hybrid and turbocharged vehicles). An interesting side effect of all this could be a reduction of global fossil fuel use and emissions over these past 40-50 years--I wonder how much an impact that would have on other factors (climate, economy, development of electric vehicles, etc.)?

I can see it catching on in shipping, but also in diesel locomotives--&, to some degree, in SSKs (outside the U.S.)

I'd love to see somebody like Vic Edelbrock or Leo Goosens find out about it & apply it to, frex, the Cummins Diesel Special for Indy in '52 or so: a TC diesel putting out insane hp, & getting national attention?

If it's used (to any appreciable degree) by racers or rodders, I can believe it'd replace the turbos in the '80s, & the blowers since then, with smaller displacement becoming more common sooner. Especially in Europe. I'm picturing smokin' SAAB 900TCs, TC Dino 204s, & Mini Coopers ( ), & maybe FIAT 124s or Alfa Spyders. (FYI, the OTL 246 is the prettiest design I've ever seen. )

The prospect of a "TC era" in F1 in the '60s or so (not turbos in the '80s) has a certain cool--but the idea of scary-powerful TC engines with the skinny rubber & no wings... You thought there were a lot of deaths in F1 OTL. (OTOH, if it moves FIA to make racing safer sooner... )

Effects? It could cut GHGs perceptibly. It might delay the introduction of CAFE (if not butterfly it {I wish!}) & maybe hybrids, too. If it promotes diesel use, could it lead to wider U.S. acceptance? And lower fuel costs generally? (Does that all, ultimately, mean more miles driven? )

Culturally, I picture the '60s "hp wars" lasting longer (presuming the insurance industry doesn't kill it off...), because the oil shock (given it's not butterflied by political changes) won't, IMO, if TCs can offer better mileage at comparable (to OTL) performance.

I'm not sure it would change the direction of the auto industry too much, with cheap gas still being a fact in the U.S. IMO, it becomes a matter of relative size--& it's possible cars TTL end up being bigger than OTL, generally, because there's more power available without a fuel cost penalty. Racing (NASCAR in particular) might still push for lighter weight & better aerodynamics, for a winning edge, & that might percolate into street cars...but somehow, without OPEC's smack, I don't see it happening on OTL schedule. (The lighter weight & shorter WB advantages of gassers & altereds are too narrow-focused & contrary to passenger comfort to gain broad appeal.)

I wonder if there might end up being TC kits to allow conversions of existing engines, to retrofit it on late '40s or early '50s engines, after it becomes more common (if it does): an aftermarket TC kit for, say, the 392 hemi or 303 Olds, in the fashion of the 6-71 Jimmy kits. (I'd presume crate engines would still be available eventually, too.) The thought of being able to run a '55 Coronet with a TC 392? (Almost as much as a hybrid 392. And if hybrids come along anyhow...both?)

 

[EverKing]

FYI, the OTL 246 is the prettiest design I've ever seen.

As pretty as it is...it is no Alfa Romeo Tipo 33 Stradale. I am obsessed with that car. Even more so considering it was producing about 230 hp out of a 2.0L Naturally Aspirated V8 in 1968! That's 120hp/litre, numbers we barely see even today except in Forced Induction engines.

The prospect of a "TC era" in F1 in the '60s or so (not turbos in the '80s) has a certain cool

Well, one could argue that we are currently in the TC era of F1. When they went down to the Turbo-V6s a few years back they include a Heat Motor Generator Unit (MGU-H) which can most easily be described as a turbo-compound turning an electrical generator which powers a battery store and can be used together with the Kinetic Motor Generator Unit (MGU-K) to power the Kinetic Energy Recovery System (ERS-K, formerlly KERS) which is a hybrid-type electric motor providing additional power to the drivetrain.

But, yes, a TRUE TC era prior to the 1980's Turbo insanity, could be epic. Even more likely than an early TC era in F1, however, would be a TC era in LeMans where endurance and power are pushed to the limits. I could definitely see this happening during heyday of the 1960's and after a few early years of regular powerplant failures they work the worst of the bugs and make it useful and reliable for road/racing use...and then everything changes.

I wonder if there might end up being TC kits to allow conversions of existing engines

I have actually been thinking about this off-and-on for the past few years. I love the idea of TC and think well developed TC kits could extend the life of popular old V8s. I think the best market to hit first would be the Chevy Small Blocks just because everyone seems to modify them. A TC kit would probably require a custom bell housing to incorporate the gearbox connecting the blowdown turbine to the flywheel before the clutch and installation may be a problem in vehicles where the engine sits far back against the firewall. I do think it is possible, though. Of course, an easier "bolt on" application could use a chain or even a belt to transfer power to the front of the crank.

EDIT:

I would love to know what it looked like...

Here's the diagram from the report:

 

[vl100butch]

as much as I want you to get back to the "shoot 'em up" parts of the story, this is fascinating!!!!

what would something like this do to a design like the B-50? seems to me you could set up an underwing pod for the engines and generate enough horsepower where mounting additional jet engines wouldn't be necessary...

OR, what would this do to a Mosquito???

 

[tomo pauk]

OR, what would this do to a Mosquito???

Mossie and A-20 would've went to easy 2 x 2000 HP, the B-26 to 2 x 2500?

There is plenty, plenty of power more or less wasted though the exhausts. Per this diagram, for every 3 HP provided to the prop, there was a potential of extra 5 HP that just exited through exhausts - piston engines of the era were lousy in 'HP per fuel used' category. Granted, some of this power was used to provide exhaust thrust (easy to do on a V12, harder but still doable on a radial), or to drive a turbochager, however as we can see the potential was simply great:

 

[jefropas]

For comparison of OTL and ATL Ploesti mission, compare the above Narrative Mission Report with the actual, historical one Found Here (begining about 1/4 way down the page). In the OTL report, it says that Capt. Bischoff (in A/C #43-28549, ITTL an un-modified P-38H-20-LO) was the one believed to have crashed into a locomotive but in the ATL I replaced this with Lt. Joye and had him survive thanks to being in A/C #43-28807 (his historically assigned A/C), which by production number is ITTL a P-38H-20-LO with the Aileron Boosters added at the Modifican Center, allowing him to roll his wing clear of the obstacle and survive the mission.

Regarding the idea of hardening annealed aluminum in the field, I was inspired to include it based on a similar account from the 91st Bomb Group (Bassingbourn, England) which required they fabricate a replacement engine mount. Since I do not have a copy of the mentioned Sheet Metal Handbook, I based the methods for properly hardening the material on this document. The most important part of that story was to illustrate how to improvise and adapt and just how creative and resourceful these amazing ground personell were.

The description of Bill Waddell's run-about (as well as the image of him welding on a barrel), his friendship with Rum Fannin and Johnny Clark, and the description of the "Machine Shop" are all thanks to member @Butchpfd. Of course, the "shout out" to T/3 (later T/Sgt) Felix Pastorus is thanks to @jefropas.

Next Chapter will bring the 479th and the ATL P-38J/K into action...

Until then, Cheers!
E

EDIT: I forgot to mention. The USAAF Ser.No's of the A/C lost on the mission and their assigned Pilots were from an MACRs (Missing Air Crew Reports). I believe some of these (or at least summary) may be on the 1st FG site (linked above as the source of the OTL NMR) and another summary site at http://www.aviationarchaeology.com/src/AFmacrMO.htm. I assigned the same airplane (by ser#) to each pilot but updated the A/C type/descriptions according to the modified production timeline of TTL. The Boosted Ailerons ITL were started to be added by the Mod.Center begining with P-38H-20-LO A/C#43-28574 (OTL this A/C was a P-38J-15-LO).

Not to be a nitpicker, our last name is Pasteris...thanks, keep it up!

Jeff

 

[Draconis]

Mossie and A-20 would've went to easy 2 x 2000 HP, the B-26 to 2 x 2500?

There is plenty, plenty of power more or less wasted though the exhausts. Per this diagram, for every 3 HP provided to the prop, there was a potential of extra 5 HP that just exited through exhausts - piston engines of the era were lousy in 'HP per fuel used' category. Granted, some of this power was used to provide exhaust thrust (easy to do on a V12, harder but still doable on a radial), or to drive a turbochager, however as we can see the potential was simply great:

View attachment 386279

Very well put. And that is a very informative and descriptive diagram. I know because I used it myself in my old Turbo-Compounding thread .