Aircraft Modifications

[Lightning Guy]

Ok. I gave this some thought.

Of course I would modify a P-38. In the first place I would replace the V-1710s with Griffons (the airframe could have handled the extra power and the engines were nearly identical in size). Since the Griffons had their own mechanical supercharges I would remove the B-33 turbos making room in the booms for a water-methanol injection system and a second generator. I also would have fitted the engines with exhaust shrouds to provide some residual thrust. Finally (to the engines anyway) I would have fitted the HS paddle-blade props.

The airframe I would modify along the lines of the 'Swordfish' P-38 to delay the onset of compressibility and improve diving speed.

Finally, I would have adopted the 2 20mm cannon and 4 .50cal armament that Lockheed was intending to fit to the P-49.

Originally Posted by DaveB.inVa

I wouldve gave most WWII bombers and fighters water/methanol injection. Fighters did use it quite a bit for extra power in a dogfight but the bombers could've used it to allow more power during takeoff. Almost all sides sent their bombers off with as much bombs and fuel as they could (adjusting accordingly for range to target) and Im sure the extra power for takeoff would've been appreciated.

For the B-29 I've saw pictures of a couple versions with a probe extending forward of the cockpit for aerial drogue refuelling. That would've been nice. It would've been hard to refuel as many aircraft as were normally sent on a large mission, but perhaps have a couple squadrons equipped so they could really reach out there. The crew of Bockscar would have appreciated that on the Nagasaki mission as well.

Many bombers did have ADI (water/methenol injection - though the Allies used a higher ratio of water to methenol than the Germans). It is listed as ADI if its listed, but it was not critical for anything but takeoff, as most bombers didn't use "WEP" for combat. Check out the B-26 and A-26 in particular (the A-26 did use it for "combat power").

By late in the war almost German/British/American fighters had water injection. The most notable exception is the P-51. It didn't have any overheating issues and the radiator thrust system worked best if the engine were running at full temp, so it was not felt to be useful.

=S=

Lunatic

Originally Posted by mosquitoman

IMO the RAF heavy bombers needed an ventral turret so I would have put them on Lancasters, Halifaxes and Stirlings. It would have prevented a lot of german nightfighter kills as the Schrage Musik cannons were fitted to fire upwards into a bomber

Some Lanc's did have a ventral turret or gun position, but for some reason this was not felt worth the weight, crewman, or obstruction of the bombay in most Lancasters.

Originally Posted by Lightning Guy

Ok. I gave this some thought.

Of course I would modify a P-38. In the first place I would replace the V-1710s with Griffons (the airframe could have handled the extra power and the engines were nearly identical in size). Since the Griffons had their own mechanical supercharges I would remove the B-33 turbos making room in the booms for a water-methanol injection system and a second generator. I also would have fitted the engines with exhaust shrouds to provide some residual thrust. Finally (to the engines anyway) I would have fitted the HS paddle-blade props.

The airframe I would modify along the lines of the 'Swordfish' P-38 to delay the onset of compressibility and improve diving speed.

Finally, I would have adopted the 2 20mm cannon and 4 .50cal armament that Lockheed was intending to fit to the P-49.

This is the plane I'd change too.

Merlins (as suggested by Jug) would not have done much for the P-38, the turbo-supercharged Allisions were every bit as good.

I don't think the Griffon would be an option without a very major redesign, as they are considerably bigger and heavier than the Allisons and require much bigger radiators. Late model P-38's had ADI (water injection). And you still need to mount one stage of the supercharger externally. If you're going to go that far, why not put R-2800's on it and get even more usuable power for less weight and avoid the cooling problems? Also, there was no US source for the Griffon and British supplies were fully utilized by the Brits.

I'd have made the following changes to the P-38 (assuming no technology transfers from any other country are possible).

1) Use a more conventional wing design, or a laminar flow type wing. Use squared off wingtips to ease production. Increase the fuel load in the outboard wing panels using the added space.

2) Put the 3 bladed paddle props ala the P-38K on the production model. (or maybe 4 bladed - not sure of the issues).

3) Subject to wind tunnel tests... extend the tail fins higher and raise the stabilizer fin to the top of the tail fins to avoid turbulence comming off the fuselage and/or wings and improve leverage. Kind of like on the North American OV-10 Bronco FAC/Counter-insurgency plane.

4) Redesign the canopy with a bubble top and move the cockpit forward a bit. Angle the front down some so the pilots downward view is improved.

5) Put at least a 4 mm armor plate over the top turbine containers and fuel feeds to the engines. Alternatively, install some kind of fire extinquisher system.

6) Remove the 20mm from the nose and replace it with a .50 BMG.

7) Install two 20mm's, one in each wing root, inside the propeller arc with 250 rpg (or more) with the ammo feeding from the fuselage using power assisted feeds. Stagger the left and right guns slightly to maximise ammo loads. (Remember the pilot is sitting more forward so there's pleanty of room).

=S=

Lunatic

[cheddar cheese]

Ok, heres what id do.

Take a P.108A and replace its 1350hp Piaggio engines with Griffons. I would then add a an anxillary jet engine to each side, B-36 style. I would lengthen the wingspan in an effort to increase altitude and also add a fuselage section from a P.108C (as it was bigger) therefore it would be able to carry more bombs

[The Jug Rules!]

Hey lightning guy, what a p-49?

[the lancaster kicks ass]

Originally Posted by RG_Lunatic

Some Lanc's did have a ventral turret or gun position, but for some reason this was not felt worth the weight, crewman, or obstruction of the bombay in most Lancasters.

whilst it would have been usefull, it prevented the use of H2S, was very heavy, not much ammo and generally not worth it, due to lack of time i haven't given many reasons but i can give more when i have more time....................

[The Jug Rules!]

My second mod would be a p-39 with a supercharged Allison. I would lengthen the fulselage fore and aft the cockpit to make room for more .50 ammo and the supercharger. The intercooler would be mouted on the side (like on the experimental model). I would mount a laminar flow wing with clipped tips,and put two or four.50's within the wing structure. I would replace the 37mm with a 20mm cannon.

[Lightning Guy]

The P-49 was a development of the P-38 with a pressurised cockpit and utilizing expiremental XIV-1430 engine. The engines were crap so the project never went anywhere.

Fitting Griffons wouldn't have been that much trouble. It was not that much bigger that the Merlin and the Allison was a little bigger than the Merlin as well. It certainly would have been no more trouble than the swap made for the Spit.

R-2800s would have killed the range of the P-38 since it guzzled fuel at a far greater rate that an inline engine.

One other modification I forgot to mention. I would get rid of the stupid elevator balances since they didn't do anything other that kill a few pilots trying to bail out.

[DaveB.inVa]

Ive seen some papers before that showed where a B-29 or two was tested with water methanol injection. It safely gave each engine around 400~600 more horsepower. Each R3350 had a port for it on the carburetor or throttle body for fuel injected engines. According to the documents I read the reason the ADI wasnt added was 1. for cost and 2. the War Emergency setting gave around that much power already, especially with the fuel injected versions. Of course they sortof overlooked the fact that the WE setting was not a great idea during takeoff whereas the ADI would have cooled the engine plus add the needed power.

Originally Posted by Lightning Guy

The P-49 was a development of the P-38 with a pressurised cockpit and utilizing expiremental XIV-1430 engine. The engines were crap so the project never went anywhere.

Fitting Griffons wouldn't have been that much trouble. It was not that much bigger that the Merlin and the Allison was a little bigger than the Merlin as well. It certainly would have been no more trouble than the swap made for the Spit.

R-2800s would have killed the range of the P-38 since it guzzled fuel at a far greater rate that an inline engine.

One other modification I forgot to mention. I would get rid of the stupid elevator balances since they didn't do anything other that kill a few pilots trying to bail out.

Griffons were bigger and heavier than Merlins/Allisons. The Allison weighed 1345 lbs (1 stage supercharger, 1710 ci), the Merlin weighed 1690 lbs (2 stage supercharger, 1647 ci), and the Griffon weighed 1980 lbs (2 stage supercharger, 2240 ci) and the R-2800 weighed 2350 lbs (2 stage supercharger, 2800 ci). By the time you figure in the weight of the coolant, the R2800 and Griffon probably weigh about the same. The Allison on the other hand was quite a bit lighter than even the 2-stage Merlin, and the Allisons turbocharger unit could be placed well back of the engine, which was not possible with the supercharger. So balance is a real issue even when considering a Merlin, let alone a Griffon.

1980 lbs in a near the front of the boom is a lot more than 1345 lbs at the front of the boom and a turbocharger in the middle, and of course the radiators would have to be made larger and more coolant would need to be carried. The booms would have to be significantly lengthened, and this would mean they'd need to be a lot heavier. With the R2800, the package was very stout, so less modification would probably be needed, as the props would sit nearer and probably below the wing a tad (like on the Tigercat), but again the booms and other structures would have to be beefed up to support the weight.

And Griffon's didn't get great fuel economy either. It's not that radials didn't get as good of fuel economy as inlines, it is that they were bigger. Bore and stroke of the Griffon was 6 inches x 6.6 inches, where for the R2800 it was 5.8 inches x 6 inches, so we'd actually expect the R2800 to get better fuel economy per cylinder than the Griffon (of course, it had half again as many cylinders). There was a fuel charge burn efficiency issue with large cylinders and the R2800 was a little past the threshold, the Griffon moreso.

But really I think it is inapporpriate to consider taking an engine from another country for such a "mod". The Griffon simply was not available for the P-38. Also, there were no reverse direction Griffons available even in England (maybe this could be handled through gearing? But if so, why was it not done on the P-38 to start with?).

I think for this topic to be legitimately considered, we have to limit ourselves to technology and parts that were available to the country in question at the time.

=S=

Lunatic

[Lightning Guy]

Why not take the Alisons from the P-82 then?

My problem with the R-2800 (in a P-3 is that this would require a MAJOr redesign to the booms (it's 4ft wide remember). Also, range would drop considerably and there really wasn't anywhere to put extra fuel in a P-38.

Originally Posted by Lightning Guy

Why not take the Alisons from the P-82 then?

My problem with the R-2800 (in a P-3 is that this would require a MAJOr redesign to the booms (it's 4ft wide remember). Also, range would drop considerably and there really wasn't anywhere to put extra fuel in a P-38.

I agree the R-2800 would be inpractical. I just think the Griffon would be as well. I don't see anything wrong with the Allison, with the K type prop the plane had plenty of usable power.

There would be plenty of room in the wings for more fuel according to my suggested re-design. The wings would probably be kinda like the P-47N wings, perhaps with the max chord a tad more forward of center (making it more traditional but still somewhat laminar flow), so there would be much more room outside the engines than on the actual P-38 wings. There would also possibly be some space for fuel behind the cockpit (which is moved forward), and the fuselage section could maybe even be extended back a tad as the tail fin is high so turbulence does not have to settle out between the back of the fuselage and the front of the tail plane.

=S=

Lunatic

[Lightning Guy]

I think that would start running into problems with weight. And all the extra weight ourboard the engines would do nothing for maneuverability. All in all, it's starting to look nothing like a P-38.

If you want to add fuel, I think a better option would be to add fuel in the enlarged center wing section from the Swordfish. Being closer to the rotational axis there would be less effect on roll rate.

[DaveB.inVa]

Originally Posted by RG_Lunatic

I don't see anything wrong with the Allison, with the K type prop the plane had plenty of usable power.

Exactly! The Allison combination used in the P-38 is pretty dang good as it is. Its got turbos feeding the single stage supercharger. In my opinion thats better than the 2 speed 2 stage Merlin. Many are so enthused by the Merlin because thats what powered most P-51's and just assume that Merlin is Gods gift to engine! But they fail to account the induction arrangement and exactly WHY most Allisons performed the way they did and WHY most Merlins performed the way they did. They just flat out discount the Allison and can not explain WHY!

LG I know you understand this and I dont mean it as anything personal at all, I just see this a lot in other places and with people and had to get it off my chest!