syscom3
Pacific Historian
So my point is valid. There might have not been engine availability for the P38
P-38 with Roll-Royce Merlins
- Thread starter Marshall_Stack
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Twitch
Staff Sergeant
The Allison weighed 1,345 lbs. and the Merlin 1,690 lbs. Performance wasn't the original issue in this thread was it? Wasn't the idea to improve cold/wet weather problems with the P-38? To stick them only in ETO birds would have probably been to much engineering for the results.
wmaxt
Staff Sergeant
Twitch said:
I've seen several quotes on the Merlin installation ranging from adding a 1,000lbs, to an even trade weight wise.
The first Merlin conversion proposal was because they were still having a few problems with it when they originally designed it. At the time the Merlin XX was providing ~200hp more than the Allison. The second proposal was due to the engine issues in the ETO. The Problem that is never addressed is that the Aleutian campaigns P-38s did not have those engine problems even with -40 on the ground. The only difference was operating procedures.
Your right to put Merlins in ETO planes only would have required another assembly line at a minimum, nobody was willing to add that complication.
wmaxt
Gemhorse
Senior Airman
An interesting little aside to this arises in reading 'Confounding the Reich' by Martin Bowman Tom Cushing [ISBN 1 85260 507 3 ] on pg.23......
''At the end of August 1943, Wittering became a little crowded with the influx of of US personnel of the 20th Fighter Group, whose 77th 79th Sqn.'s moved into the satellite airfield at King's Cliffe. The 55th Sqn. was to be based at Wittering. The 20th was equipped with the P-38 Lightning. The CO, Major D.R. McGovern from Providence, Rhode Island, had served in the Pacific flying P-39 Airacobras and had destroyed 5 Jap aircraft. He and Bob Braham became friends. On the 20th September, Braham Jacko Jacobs in a Mosquito engaged in a local friendly dogfight with a P-38. Braham found that even though the Mosquito was worn-out and meant for training and with his [then] inexperience of the aircraft, it was, in his opinion, superior to the Lightning....''
At this time, RAF 141 Sqn. was converting from Beaufighters to NF.II Mosquitos, only being supplied sporadically with well-used ones from other units....
W/C John Randall Daniel 'Bob' Braham DSO,DSC**,not then 23, assumed command of RAF 141 Sqn. Dec. 1942, and had already shot down 12 enemy aircraft, 11 of them at night. He was then the youngest W/C in the RAF. He was eventually shot down captured but was one of the highest-scoring British NF pilots, up there with John Cunningham, by the finish of the War....
My point is that while the P-38 was a terrific aircraft [IMHO], the exercise of trying to improve performance by replacing Allisons for Merlins did work, as in the P-40 and later the P-51....
[ On pg.99, they did try using P-38J's for Intruder-work, working with RAF 515 Sqn.'s Mosquitos in late Mar. 1944, but it was disbanded in April after sorties revealed that single-seat fighters were unsuitable for Intruder Ops.....]
''At the end of August 1943, Wittering became a little crowded with the influx of of US personnel of the 20th Fighter Group, whose 77th 79th Sqn.'s moved into the satellite airfield at King's Cliffe. The 55th Sqn. was to be based at Wittering. The 20th was equipped with the P-38 Lightning. The CO, Major D.R. McGovern from Providence, Rhode Island, had served in the Pacific flying P-39 Airacobras and had destroyed 5 Jap aircraft. He and Bob Braham became friends. On the 20th September, Braham Jacko Jacobs in a Mosquito engaged in a local friendly dogfight with a P-38. Braham found that even though the Mosquito was worn-out and meant for training and with his [then] inexperience of the aircraft, it was, in his opinion, superior to the Lightning....''
At this time, RAF 141 Sqn. was converting from Beaufighters to NF.II Mosquitos, only being supplied sporadically with well-used ones from other units....
W/C John Randall Daniel 'Bob' Braham DSO,DSC**,not then 23, assumed command of RAF 141 Sqn. Dec. 1942, and had already shot down 12 enemy aircraft, 11 of them at night. He was then the youngest W/C in the RAF. He was eventually shot down captured but was one of the highest-scoring British NF pilots, up there with John Cunningham, by the finish of the War....
My point is that while the P-38 was a terrific aircraft [IMHO], the exercise of trying to improve performance by replacing Allisons for Merlins did work, as in the P-40 and later the P-51....
[ On pg.99, they did try using P-38J's for Intruder-work, working with RAF 515 Sqn.'s Mosquitos in late Mar. 1944, but it was disbanded in April after sorties revealed that single-seat fighters were unsuitable for Intruder Ops.....]
Glider
Captain
Gemhorse said:
Interesting
wmaxt
Staff Sergeant
Gemhorse said:
That is interesting, If you go here http://prodocs.netfirms.com you'll see a P-38F (the same model the 20th was first equipped with) and a Spit IX, and Fw-190A.
wmaxt
I don't think using the results of changing to the Merlin in the P-40 and P-51 would really be indicative of what would have happened had Merlins been installed in the P-38. Both the P-40 and P-51 were equipped with single-stage supercharged Allisons, while the P-38's of course were turbocharged. In the excellent book 'V's for Victory-The Story of the Allison V-1710' by Daniel D. Whitney there are many tables showing the expected performance levels attained by P-38's equipped with many different Merlins, including the XX type. It would seem that only the most advanced Merlins gave any real advantage over the V-1710-89/91's in the P-38L. In the end, the effort required to re-equip the P-38 with Merlins was not justified. The decision to stop development of the Merlin powered P-38 was handed down by Gen. Arnold himself. Another factor that may have had some bearing on his decision was that once the war was over, Packard was to start paying very expensive royalties to Rolls-Royce for continued manufacture of the Merlin. For this reason the P-82 and the P-51J were equipped with advanced V-1710's.
wmaxt
Staff Sergeant
V-1710 said:
Good info - it'll go into the info bank! I knew about the P-51J and P-82s but not Arnold's involvement. I'm sure that there were at least two decisions regarding the P-38L vrs the P-51s though, they were about two years apart.
wmaxt
DaveB.inVa
Airman 1st Class
- 225
- Dec 20, 2004
Id rather have the turboed Allison than the supercharged Merlin. The turbo setup on the P-38's Allison is much more flexable than the two speed two stage supercharger found on most versions of the Merlin. Many times youll find that because of the P-51's great leap in performance due to the installation of the Merlin, people will believe that the Allison was a much less powerful engine. Most dont consider that it was the induction system of the Merlin that made it such a great performer. If the Allison was given an induction system like the Merlin (and later Allisons did get two speed two stage superchargers) it would certainly perform much better at altitude.
My point is that the induction system must be considered. If the Allison could get the amount of oxygen at altitude that the Merlin could then the Merlin would be a much less mystical engine today. In the case of the P-38 it could get enough oxygen at altitude and could make power at altitude because of the turbochargers.
I also agree with wmaxt that operating procedures were the problem in the ETO. All the talk of cold air in Europe killing the turbos is unfounded. The B-17 and B-24 operated in that same cold air and you never heard of cold air killing their turbos.
Personally I believe the wet weather is what did them in. The turbos were mounted on top of the boom and were more exposed to the weather than the turbos of bombers which were underneath the wing. Operating procedures in Alaska were obviously improved as problems were less prevalent.
My point is that the induction system must be considered. If the Allison could get the amount of oxygen at altitude that the Merlin could then the Merlin would be a much less mystical engine today. In the case of the P-38 it could get enough oxygen at altitude and could make power at altitude because of the turbochargers.
I also agree with wmaxt that operating procedures were the problem in the ETO. All the talk of cold air in Europe killing the turbos is unfounded. The B-17 and B-24 operated in that same cold air and you never heard of cold air killing their turbos.
Personally I believe the wet weather is what did them in. The turbos were mounted on top of the boom and were more exposed to the weather than the turbos of bombers which were underneath the wing. Operating procedures in Alaska were obviously improved as problems were less prevalent.
Jabberwocky
Staff Sergeant
Argh, forum ate my post.
DaveB.inVa said:
Good points. Also, it must be noted that the Allison V-1710 was intended to be a turbocharged engine. The P-37, P-38, and P-39 were all orginally designed to use the turbocharged Allison. Consider what a dissappointment the P-39 turned out to be without a turbocharger, and also note the performance (or lack of performance!) of the Lockheed P-322 Lightning with non-turbocharged V-1710-C15's. In addition, the XP-49 Lightning development didn't have any performance advantage with it's 1,600 h.p. Continental XIV-1430's over the P-38L. Wonder what a P-39 would have been like with a Merlin? Probably close to the P-63, which had a 2 stage supercharged V-1710.
- Thread starter
- #33
Marshall_Stack
Senior Airman
Deleting the turbocharger on the P-39 cost American lives. I read that NACA (predessor to NASA) deleted it because of drag counts (the air inlet). I am a fan of the underdog; I would like to have seen what it could have done with the turbos. The life of the plane would probably have still been short due to its lack of range.
syscom3
Pacific Historian
Ive heard the primary reasons were due to the fact that General Electric was having a huge problem building the turbochargers and they werent available.
It took General Electric quite some time to get the turbocharger perfected. I believe at least one of the XP-37's crashed due to turbo failure. As for the P-39, the U.S.A.A.C. decided that it wanted the aircraft to fill the ground attack role rather than high altitude interceptor, so the turbocharger was deleted. So, not only did the P-39 loose a lot of horsepower and high altitude capability, it also became significantly heavier, due to the addition of more armor plate. Recipie for disaster.......
wmaxt
Staff Sergeant
A good article on the P-39 regarding the turbo is at this site:
http://home.att.net/~C.C.Jordan/index.html
The prototype could hit 398 at 20,000ft, thats 1943 fighter performance!
wmaxt
http://home.att.net/~C.C.Jordan/index.html
The prototype could hit 398 at 20,000ft, thats 1943 fighter performance!
wmaxt
helmitsmit
Airman 1st Class
Aren't turbochargers heavier then the the 2 stage 2 speed supercharger? Did they actually trial a merlin 60 series 1640hp on a p38?
By the way the merlin XX 1480hp was a bombers engine (Lancaster) optimised for low level.
They could have used the merlin 130 series 2000hp (De Haviland Hornet) which would have been handed.
By the way the merlin XX 1480hp was a bombers engine (Lancaster) optimised for low level.
They could have used the merlin 130 series 2000hp (De Haviland Hornet) which would have been handed.
Twitch
Staff Sergeant
My take on Allisons with turobs is simply that they obviously worked if P-38 had service ceiling of 44,000 feet! The myriad other factors simply made it a better ship for warmer Pacific ops instead of the ETO.
Also, only one of three P-82 prototypes used Allisons. Initial production aircraft were Packard V-1650-23/25s. And Packard was not hurting for building liscensed Merlins. It was a time for the company when defense contacts saw a cash flow like never before in their history.
<<BTW that's my Packard
Also, only one of three P-82 prototypes used Allisons. Initial production aircraft were Packard V-1650-23/25s. And Packard was not hurting for building liscensed Merlins. It was a time for the company when defense contacts saw a cash flow like never before in their history.
<<BTW that's my Packard
helmitsmit
Airman 1st Class
Yeah but that might be the wing design or the streamlining of the aircraft
Jabberwocky
Staff Sergeant
wmaxt said:
More like 1941-1942 performance.
FW-190s were doing 390mph + in 1941 in combat, so were Hawker Typhoons. The 109F4 was doing a few mph short of 400 in late 1941, as was the Mig 3. The Spitfire, 190A and 109G all exceeded 400mph in level flight in 1942. The P-38 was doing over 400mph as well.
One of the great 'mightofbeens' was the improved Spitfire proposed by Supermarine in 1939. Supermarine significantly reworked a Spitfire II into a "Mk III" with a two speed Merlin XX in 1940 and recorded a level speed of 400mph at 21,000 feet. They clipped the wings, added 14 Imp Gal (17 US gal) to the fuel tanks, strengthened the engine mounting, made the tail wheel retractable, re-arranged the landing gear and undercarriage and added more armour protection.
However, the RAF decided that the Hurricane was in more dire need of a performance increase and the new Merlins went to them. The other consideration of the RAF was that production numbers were more important than the extra performance at the time, the Spitfire being considered superior to the 109 by the RAF. So, instead of the large step foward with the Mk III, the RAF decided to go with the incremental Mk V, which required far less changes in the production line and had an engine more readily available in the Merlin 45.
In essence, the amount of significant changes to the Spitfire design emboldened in the Mk III meant that, even despite the very real improvements in speed, roll rate and rate of climb, there were too many changes in the airframe for it to be put into production quickly.
The RAF ended up paying for that decision over France in 1941, where a faster, stronger and more agile Spitfire could of blunted the technical advantage that the LuftWaffe enjoyed when the FW 190 appeared. Considering that the Mk III enjoyed almost identical advantages over the Mk V that the 190A did ( i.e a +20-30 mph speed advantage at most heights, better roll, better climb, better dive), a 190A vs a Spitfire Mk III would of been a far more even fight.
