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mynameisroland
02-07-2006, 07:12 AM
If the P38 was equipped with the Merlin 66 or lets say Merlin 71 would this version have outperformed the P38 L?

I have asked this before but not in a seperate thread, and the discussion was not very balanced. From what I have learned a P38 equipped with Merlins was made. Now some people have said that it would have been outperformed by Allison engined versions. I dont see how a P38 with Merlins could be anything but better. The Merlin was lighter, was producing more HP per year per model than the Allison, it had intergral two stage supercharger with after cooling so no need for the turbocharger and all of the piping that you have in the booms, it also was built in handed versions and was a very reliable and economic engine.

So straight off we are talking about a benefit in weight reduction and power to weight ratio and then also altitude performance.

I am not talking about practicality of production or economics its just a straight performance question.

mynameisroland
02-07-2006, 07:12 AM
If the P38 was equipped with the Merlin 66 or lets say Merlin 71 would this version have outperformed the P38 L?

I have asked this before but not in a seperate thread, and the discussion was not very balanced. From what I have learned a P38 equipped with Merlins was made. Now some people have said that it would have been outperformed by Allison engined versions. I dont see how a P38 with Merlins could be anything but better. The Merlin was lighter, was producing more HP per year per model than the Allison, it had intergral two stage supercharger with after cooling so no need for the turbocharger and all of the piping that you have in the booms, it also was built in handed versions and was a very reliable and economic engine.

So straight off we are talking about a benefit in weight reduction and power to weight ratio and then also altitude performance.

I am not talking about practicality of production or economics its just a straight performance question.

stathem
02-07-2006, 08:52 AM
Damn, I hope bollio_loco doesn't see this thread. He might bust his keyboard.

The Merlin 71 - is that the handed one fitted to the Hornet?

I think any (possible )performance benefit of having Merlins would be outweighed by the torque reaction of having both turning the same way.

mynameisroland
02-07-2006, 09:00 AM
The Hornet had Merlins that were 'handed' spinning in opposite directions from each other. So I guess that with a little effort this problem could be overcome.

Heres a teaser - how about a Griffon engined P38 http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

where are all you P38 fans ?

bolillo_loco
02-07-2006, 09:13 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by stathem:
Damn, I hope bollio_loco doesn't see this thread. He might bust his keyboard. </div></BLOCKQUOTE>

Originally made my =AFJ=Mantis

http://img.photobucket.com/albums/v358/bolillo_quemado/P-38whinning.jpg

berg417448
02-07-2006, 09:34 AM
The only negatives that I've ever read about a merlin powered P-38 were that allegedly the rate of climb would have been slightly less and the service ceiling would have been less. Another negative was the fact that the production lines would have to be shut down for a period of time (opinions vary as to length) to make the necessary design modifications and the War Production Board was unwilling to do that.

WOLFMondo
02-07-2006, 09:38 AM
Why would the RoC and altitude performance be reduced? Surely that depends on the Merlin/supercharger combination used. It wasn't like the Merlin wasn't used on Spitfires and Mosquito's cruising at 30,000ft+. Merlins like Griffons were tweaked to go up past 40,000ft. As pointed out also the Merlin equipped P38 would be lighter than the Allison equiped P38.

horseback
02-07-2006, 09:43 AM
From my reading on the subject, the Merlin was suggested as a replacement for the Allisons in the P-38 AFTER the development of the Merlin Mustang, by which point Packard's extra production had solved the problem of supply.

Remember that the Spitfire Mk IX/VII/VIII was still relatively rare in the first half of 1943, due to the demand for Rolls Royce Merlins for Spits, Hurricanes, Mosquitos and Lancasters. The new 60 series engines had to 'take a number' in the priority list.

Similarly, the P-38 had all kinds of production problems early in the war due to the difficulty of m*** producing a design that had been envisioned as a production run of a maximum of 150 aircraft. Its production/supply issues had seemingly been solved about the same time as the supply of Merlins became sufficient for all the RAF/USAAF demands. Allison, as a division of GM, would have resisted replacement by the Merlin with a great deal of political muscle.

However, the Merlin Lightning would have been a much lighter aircraft, ***uming that the political and Merlin supply issues had been solved a year or so sooner.

***uming, however, that the different thrust-line of the Merlin could be adjusted for in the nacelle design, the Merlin Lightning would be a better fighter. What I would question is whether the improvements would be tranforming.

Not needing the turbosuperchargers and their ***ociated piping, the weight savings would have vastly improved the Lightning's already respectable climb and accelleration. I don't think that it would have translated into a significant improvement in top speed or high altitude handling, where the Lightning sometimes verged on compressability in level flight.

Maneuverability would have been somewhat better as well, with the improved power-to-weight ratio, but the aircraft would still have been subject to dive limitations, and less suited to long range, high-alt escort in the ETO than the Merlin Mustang.

In short, while its strengths would have become greater, its only fault that would have changed would have been reliability in the 8th & 9th Air Forces. The cockpit layout and complexity would still be more demanding than single-seat fighters, it still would have (possibly even greater) compressibility problems in the dive and high speed high alt flight, the cockpit would still need adequate heating, its size & unique planform would make still it more easily identified by its enemies and the (initial) roll response would still be sluggish until they were hydraulically boosted.

The Merlin Lightning, if developed and produced in numbers before the Merlin Mustang, might well have been quite effective in 1943-44, but if produced in tandem with the Mustang, I think Doolittle would have come to the same conclusion; the Mustang was a much better fighter for the job/money.

cheers

horseback

Jungmann
02-07-2006, 09:46 AM
Don't recall a Merlin-powered P-38 prototype. Reference, please?

WOLFMondo
02-07-2006, 09:52 AM
P38K?

berg417448
02-07-2006, 09:53 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WOLFMondo:
Why would the RoC and altitude performance be reduced? Surely that depends on the Merlin/supercharger combination used. It wasn't like the Merlin wasn't used on Spitfires and Mosquito's cruising at 30,000ft+. Merlins like Griffons were tweaked to go up past 40,000ft. As pointed out also the Merlin equipped P38 would be lighter than the Allison equiped P38. </div></BLOCKQUOTE>

I have no way of knowing if it is true but the claim was that the Packard Merlin XX made less power above 30,000 feet than the Allison V1710.
We won't know...that plane was never made.

berg417448
02-07-2006, 09:56 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WOLFMondo:
P38K? </div></BLOCKQUOTE>


P-38K wasn't Merlin powered.

mynameisroland
02-07-2006, 10:22 AM
My rationale was based on the fact that the Merlin 66/71 produced equivalent or more HP at a lesser weight at most altitudes. Combined with the lower installed weight and the reduction in ***ociated weight with the removal of unessecary turbo gear and piping , would have allowed for greater fuel/payload capability and translate directly in to increased ceiling climb and level performance.

The P38 would have been transformed in to and even better fighter than it was historically ***uming the change in CoG would have been simple to fix and 'handed' merlins were provided. In 1944/45 you have Merlins running at over 2000HP thanks to higher boost and better octane fuel. With no ***ociated weight gain and benefitting from an extra 2x 300hp increase the Lighting would have been awsome below 25,000ft where comopressibility is less of a problem.

Political, financial, and practical reasons aside from a performance point of view it would have made sense.

WOLFMondo
02-07-2006, 10:26 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by berg417448:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WOLFMondo:
P38K? </div></BLOCKQUOTE>


P-38K wasn't Merlin powered. </div></BLOCKQUOTE>

I think that was the verson that it was tried out on or would have been.

berg417448
02-07-2006, 10:31 AM
They made some strange decisions. They didn't even need to switch to Merlins to get increased performance. Check out the Allison powered P-38K:

"Flight tests were conducted from late February through the end of April 1943. Performance was better than hoped for. Maximum speed at critical altitude (29,600 ft) was 432 mph (Military Power). At 40,000 feet, the "K" zipped along at a speed that was 40 mph faster than the current production P-38J could attain at this same height. Maximum speed in War Emergency Power, at critical altitude, was expected to exceed 450 mph. The increase in ceiling was just as remarkable. Flown to 45,000 ft on an extremely hot and humid day, Lockheed engineers predicted a "standard day" service ceiling in excess of 48,000 ft! Improvement of the cowling fit and the elimination of the heavy coat of paint would have gained even more performance. Due to the added efficiency of the new propellers, range was expected to increase by 10 to 15 %. Lockheed appeared to have a world-beater on their hands.

The plane, now designated the P-38K-1-LO was flown to Elgin Field for evaluation by the USAAF. Flown against the P-51B and the P-47D, this Lightning proved to be vastly superior to both in every category of measured performance. What astounded the evaluation team was the incredible rate of climb demonstrated by the P-38K. From a standing start on the runway, the aircraft could take off and climb to 20,000 feet in 5 minutes flat! The "K", fully loaded, had an initial rate of climb of 4,800 fpm in Military Power. In War Emergency Power, over 5,000 fpm was predicted.

In light of this incredible level of performance, you would certainly expect that the Government would be falling all over themselves to quickly get the P-38K into production. Yet, this was not the case. The War Production Board was unwilling to allow a short production suspension in order to get new tooling on line for the required change to the engine cowling. Even when Lockheed promised that the stoppage would only be for 2 or 3 weeks, their request was turned down."

http://home.att.net/~C.C.Jordan/P-38K.html (http://home.att.net/%7EC.C.Jordan/P-38K.html)

mynameisroland
02-07-2006, 10:33 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by berg417448:
They made some strange decisions. They didn't even need to switch to Merlins to get increased performance. Check out the Allison powered P-38K:

"Flight tests were conducted from late February through the end of April 1943. Performance was better than hoped for. Maximum speed at critical altitude (29,600 ft) was 432 mph (Military Power). At 40,000 feet, the "K" zipped along at a speed that was 40 mph faster than the current production P-38J could attain at this same height. Maximum speed in War Emergency Power, at critical altitude, was expected to exceed 450 mph. The increase in ceiling was just as remarkable. Flown to 45,000 ft on an extremely hot and humid day, Lockheed engineers predicted a "standard day" service ceiling in excess of 48,000 ft! Improvement of the cowling fit and the elimination of the heavy coat of paint would have gained even more performance. Due to the added efficiency of the new propellers, range was expected to increase by 10 to 15 %. Lockheed appeared to have a world-beater on their hands.

The plane, now designated the P-38K-1-LO was flown to Elgin Field for evaluation by the USAAF. Flown against the P-51B and the P-47D, this Lightning proved to be vastly superior to both in every category of measured performance. What astounded the evaluation team was the incredible rate of climb demonstrated by the P-38K. From a standing start on the runway, the aircraft could take off and climb to 20,000 feet in 5 minutes flat! The "K", fully loaded, had an initial rate of climb of 4,800 fpm in Military Power. In War Emergency Power, over 5,000 fpm was predicted.

In light of this incredible level of performance, you would certainly expect that the Government would be falling all over themselves to quickly get the P-38K into production. Yet, this was not the case. The War Production Board was unwilling to allow a short production suspension in order to get new tooling on line for the required change to the engine cowling. Even when Lockheed promised that the stoppage would only be for 2 or 3 weeks, their request was turned down."

http://home.att.net/~C.C.Jordan/P-38K.html (http://home.att.net/%7EC.C.Jordan/P-38K.html) </div></BLOCKQUOTE>

So how would this P38 be better than a Merlin 66 powered P38 running at 25 lb boost ?

berg417448
02-07-2006, 10:39 AM
Maybe only since It would have been available sooner? Hard to compare since no Merlin powered P-38 ever existed.

mynameisroland
02-07-2006, 10:50 AM
In 1943 there were plenty of Merlins, the Fw 190 D9 was 1st test flown in 1942 and used essentially the same engine and final configuration as the Dora 9 did in 1944. If it wasnt for Tank pissing about with the DB 603 maybe the Fw 190 D9 would have been available in 1943. There are plenty of what ifs.

What if the merlin was used ? This is my what if.

berg417448
02-07-2006, 10:58 AM
You misunderstood my point when I said available sooner. Production line to convert to P-38K would shut down for 2 weeks. Conversion to Merlin was estimated to shut down P-38 production line for months due to extensive re-design. Hard to understand that they didn't do either one.

mynameisroland
02-07-2006, 11:01 AM
true

WOLFMondo
02-07-2006, 12:32 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by berg417448:
You misunderstood my point when I said available sooner. Production line to convert to P-38K would shut down for 2 weeks. Conversion to Merlin was estimated to shut down P-38 production line for months due to extensive re-design. Hard to understand that they didn't do either one. </div></BLOCKQUOTE>

In 1943 though the US was starting to pick up steam in the pacific, it would need every P38 it could get, performance of the J still exceeded the latest Japanese aircraft and like with the Sherman, I suspect they needed numbers, not performance.

Xiolablu3
02-07-2006, 12:33 PM
Wasnt the Alison in the early Mustang really good down low?

Was it better than the contemporary Merlin below a certain altitude?

I remember reading that the Alison powered p51 was really good down low, but I am not sure HOW good.

berg417448
02-07-2006, 12:45 PM
Good info on the Allison mustangs here:

http://www.faqs.org/docs/air/avp511.html

Xiolablu3
02-07-2006, 01:31 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by berg417448:
Good info on the Allison mustangs here:

http://www.faqs.org/docs/air/avp511.html </div></BLOCKQUOTE>

Intersting thanks! http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

150 cannon armed 4x20mm Hispano Alison Mustangs in 1941!

It doesnt actually compare the low alt performance of the Alison Mustang vs Merlin Mustang tho.