P-38 with Roll-Royce Merlins

[syscom3]

Theres always the possibilty that all Packard built Merlins were designated for the P51, so none were available.

The Merlin equiped P51's were a magnitude better in performance than the Allison equiped Mustangs, but a merlin equiped P38 only had a slight marginal improvement over the Allisons.

If I was in charge of the aircraft production board, Id veto changing the P38 line for the "umpteenth time" for such little over all improvement.

[Nonskimmer]

Originally Posted by syscom3

Theres always the possibilty that all Packard built Merlins were designated for the P51, so none were available..

Packard Merlins were also installed on Canadian built Lancasters.

[KraziKanuK]

Originally Posted by Nonskimmer

Packard Merlins were also installed on Canadian built Lancasters.

And Mossies.

[Nonskimmer]

Ah yes.

[pbfoot]

and the Hurricane

[syscom3]

So my point is valid. There might have not been engine availability for the P38

[R988]

Originally Posted by syscom3

So my point is valid. There might have not been engine availability for the P38

They made a P-40F with a Merlin but had to discontinue it due to lack of available engine I think, so that is definately a valid point, that and the cost to benefit ratio would have been vetoed the idea.

[Twitch]

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]

Originally Posted by Twitch

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.

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]

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.....]

[Glider]

Originally Posted by Gemhorse

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.....]

Interesting

[wmaxt]

Originally Posted by Gemhorse

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.....]

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

[V-1710]

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]

Originally Posted by V-1710

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.

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]

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.