Modified P-38

Started by sedonakevin, February 19, 2013, 06:00:59 PM

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PR19_Kit

Quote from: kitnut617 on February 21, 2013, 06:47:42 AM
I've read that the turbos were on the US Governments restricted list (read US only) so any aircraft that had them, didn't when they got to the UK.

Good thing our Government didn't take the same attitude about the Merlin then..........
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

tomo pauk

Hello, gentlemen,
The turbo-supercharged B-17s were flying in RAF service from mid 1941 on, being negotiated in early 1940. So it seems that a ban on exporting the turbos was/is a misinformation, rather than a fact (at least for planes purchased by UK). The engines chosen for the RAF's Lightnings were the same as for their Tomahawks (= early P-40s), ie. the C-15 subtype of V-1710 - engine choice being driven by commonality, rather than by engine power? Such Lighnings were also cheper than turbo-P-38s, a significant thing prior LL was in force.
Those engines were of lower power than F-3 engines found in Mustangs RAF ordered, along with Kittyhawks.

Another thing was that C-15 engines were of same rotation, and that was detrimental in case of P-38 Lightning*. Then we have the intake and exhausts of dubious layout. The intake was lying flush with cowling, without any boundary layer splitter - unlike the installations found at P-40 and P-51. Not good for taking advantage of ram effect. The exhausts were routed in single pipe per engine's side, unlike most of the known inline-engined planes had (short, individual exhausts). So the exhaust thrust is not harvested as the engine would permit it. The net resut was fighter that would be good for 1940, but not for 1942, when the turbo-less Lightnings were delivered.

*USAF was also fielding turbo-less P-38s, for training purposes, with F series engines and handed propellers (different rotation)

andrewj

Although not fitted with a turbo-charger , the Allison V-1710-C15 engine did have a mechanical supercharger, perhaps the British authorities thought this would be sufficent in light of experience with the Merlin.

Andrew

tomo pauk

Indeed, as any 'proper' ww2 aircraft engine, the integral supercharger was there int he V-1710-C15. Unfortunately, wile the the C15 was a decent engine when the British were negotiating for it to be installed in Lightning (April 1940), it was lousy engine for March of 1942, ie. in the time 1st examples were received in the UK. The engine was rated, in 1942, at 1040 HP for take off and at 14300ft, and at 1090 HP at 13200 ft, the Merlin III (BoB vintage) for 1030 HP at 16250 ft (some 1300 HP at lower altitudes?). In any comparison with Merlin 45, or with XX, let alone with coming-soon two-stage Merlin, the C15 is under-performer.
So the Lightning with C15 engines become an expensive 350-360 mph fighter, not something RAF needed or wanted in 1942.

KJ_Lesnick

Quote from: sedonakevin on February 19, 2013, 06:00:59 PMI've long toyed with the idea of building a 1/48 model of a carrier capable P-38 Lightning.  The folding wings are no problem, my wonder is where to put the arrester hook.  My primary thought is along the centerline of the cockpit tub (as if it were attached to the main wing spar).
Sounds like a good idea...

QuoteOne of my buddies in the local model club (IPMS Prescott AZ) suggested a hydraulically operated triangular contraption attached to both tail booms behind the main landing gear (again attached to the main wing spar).
I'd recommend against it, looks like it would add needless drag .


Quote from: wuzak on February 20, 2013, 02:03:54 AMMaybe a telescoping tail hook.
Has that ever been put on a carrier plane of that era?  If not, it sounds like it would add unnecessary complications.

QuoteFor the Navy P-38 are you going to ditch the turbos? Turbos were mainly an Army thing.
I don't see why not, we're talking about a USN design (which I guess would either be called the FV-1 or FO-1) right?

The USN had some experiences with turbochargers (they put them in at least one variant of the PB2Y), turbos were already part of the design, and they are easier to achieve performance at altitude.


Quote from: famvburg on February 20, 2013, 06:35:16 AMIIRC, the couple of real proposed naval variants had the hook in the center pod.
Well that's how you know you're on the right track; I think the idea of having twin-hooks to each boom would be a real bad if only one hook caught...


Quote from: kitnut617 link=topic=36670.msg590245#msg590245I've read that the turbos were on the US Governments restricted list (read US only) so any aircraft that had them, didn't when they got to the UK.
From what I remember that had to do with the metallurgy used in the turbine.

I don't know if that had to do with all turbos or just certain variants.  Regardless we did give B-17C's to the RAF.
That being said, I'd like to remind everybody in a manner reminiscent of the SNL bit on Julian Assange, that no matter how I die: It was murder (even if there was a suicide note or a video of me peacefully dying in my sleep); should I be framed for a criminal offense or disappear, you know to blame.