Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
Things released from your aircraft at speed don't always act how you want them to - maybe there was some trouble there.
Iirc there was also a fuel reduction when bombs were fitted.
They ignored 2 stage superchargers and when they finally realized their need ,they were demanding full pressure height of 12 km!
How the Me262 could be operational in early 1944 with that leadership?
Which is pretty much standard. What I mean is that if you specify a full pressure of height of 7-8000 meters in 1943 to be delivered in late 1944/early 1945 you are setting yourself up to be in the same situation. If the British and Americans already have planes in service in 1943 (or whenever the 12km requirement was issued) then where are they going to be in 1-2 years?
First of all bombers were coming at 6-7000 meters. That s the crucial height.
Besides that, the current service fighters with their single stage superchargers , were totally outclassed and slaughtered. The priority should be the fast introduction of an 2 stage supercharger even with more modest performance. A full pressure height of 9000m would be vast improvement and would close the performance gap a lot. For performance above that height , GM1 could be used
Instead the RLM rejected any interim solutions , wanting the perfect that never came.. When the british met the Fw190 did not wait the introduction of the Spitfire XIV. They created the IX version as an interim solution to help the immediate needs.
The P-47M/N could hold full pressure (for 2100hp not 2000) to 38,750ft in late 1944. That is 11811 meters.
Not reliably in 1944
A P-38L could make 1138hp at 32,200ft (9814 meters)
Obviously turbo superchargers are un matched at altitude
With the Merlins we have the problem of deciding which pressure to use but a -9 Packard Merlin as used in the P-51H could make 1200hp at 35,000 with the engine "static" (not moving) it could make the same 1200hp act best climb speed and at high speed level flight it could make 1200hp at 40,000ft.
Germany s problem was not the middle 1945 merlin but the 1943-4 merlin. It s true that in middle 1945 the TA152H probably would match the P51H performance at altitude , but what benefit was that to the Jagdwaffe?
There is only so much you can blame on poor leadership and only so much good leadership can take credit for when it comes to some technical aspects of engine development. Sometimes it just takes time or throwing some aspects out and starting over.
In my opinion most of the problems with the major development programs were not of technical nature but of management nature. Jumo 222, Db610 , He 177,high altitude performance of the Fw 190 , Me 262 ,Do 317B,Do335A6 could have offered valuable service. There was nothing technically unsolvable
The Allison company helped turn the GE J-35 from a low powered, short lived engine to a higher powered one with a much longer life by redesigning the lubrication system.
The original engine used an oil/air mist while Allison went for a pressure system with scavenging. But it meant a total redesign of the bearing areas.
then all the resources that were squandered later on trying to develop the various high-output piston engines would have not happened...
Milch wasn't the only one..........And don't forget Schelp, who was the RLM's Engine Development director. He terminated the HeS8 and HeS30 engines in favor of the HeS011 (he preferred the axial design over the centrifugal design) and by doing this, robbed the He280 of it's much needed engine and left the Luftwaffe's jet program at the mercy of the sluggish 003 and 004 development............. and other types that were under development at that time.
In response to Shortround6 post#25 and the other posts related to the GE, P&W, Wright, and German superchargers,
The Germans had figured out the supercharger problems by about late-1942, if by no other way than the reverse engineering of the Merlin XX and later engines. The US also had figured out the supercharger problems, if by no other way than through the UK providing the Merlin XX and 60 series supercharger designs.
However, both the Germans and the US (US in the early part of the war at least) had other fish to fry, so to speak.
The Germans had to plan on maybe not having high quality aviation fuel, and the Eastern Front was using up most of their focus and resources. In addition they used direct fuel injection on all(?) their high performance engines, which had some advantages over carburetor types, but did not allow for the fuel injection into the eye of the supercharger.
The US had institutional inertia to overcome, and not just relative to the turbo installations. The Allison V-1710 did not evolve to the level of the single-stage Merlin until theRolls RoyceAllisonMerlinV-1710'G' series.The V-1710'G' could aptly be described as a 'Merlinized' and 'Hookerized' model with a slightly modified Merlin ⌀10.25" impeller, Merlin 6:1 cylinder compression ratio, and Hooker geometry for the airflow (I am not sure where the fuel was injected in the P-38L V-1710'G' series system). P&W did not come into their own until late-1944 with their R-2800 'C' series engines, and Wright not until their R-2600 'C' series? in 1945? (maybe not during the war?)
What I am saying by the above, any jokes aside, is why did the Germans and the US not simply put the Merlin supercharger on their engines? The answer is the very large amount of design, retooling, and trouble shooting that would be required. I can not say for sure how long the delay/disruption in production such a switch would have caused in 1942-43, but even today it would take a year, plus or minus a couple of months. For the US at least, while what they had for superchargers may not have been upto comparison with the Merlin, it was 'good enough' in an operational sense for the most part.
For the Germans, leaving out the fuel quality issue leaves engines that are pretty much equal to the US and UK engines in any operational sense, at least until it no longer really mattered.
It took the Germans until Sept-Oct of 1943 to clear the DB 605 to use 1.42 ATA with their existing supercharger. Using any sort of supercharger that heats the intake more is just going cause piston failure that much quicker. And compressing the air more at higher altitudes will heat the air more (raising the peak temperatures in the cylinder) even if you keep the same absolute manifold pressure (1.42 ata).
By the Fall of 1943 the Germans were getting way behind the curve on well trained replacement pilots. Blaming pilot losses in 1944 on lack of high performance superchargers is not facing the real problems.
...
We also seem to have rather vague goals for the German 2 stage supercharger/s. What pressure at what altitude?
We also seem to be assuming that a two stage supercharger will give a significant advantage over the GM 1 systems some german aircraft used.
While GM 1 was a bit of a crutch the Germans were perhaps in a better situation to use it than many other air forces.
A two stage supercharger costs weight and bulk, so does the GM 1 system. AN intercooler costs some weight and volume, and it causes drag due to airflow.
The Germans, at least when trying to intercept daylight bombing raids, have their aircraft close to sources of supply. Imagine the US trying to supply Nitrous oxide to a number of Pacific Islands. Or use it in North Africa/Southern Italy.
Two stage superchargers also require (if engine driven) considerable horsepower to run. This raises the IMEP in the cylinders much faster than the output HP at the propshaft rises which increases the need for better fuel.
In response to dedalos post#33 and possibly other's posts?,
I may not have been clear in what I was saying, sorry, possibly this is more clear?
The Germans understood the theory and possible advantages of the Merlin 1&2-stage superchargers by late-1942. If they had started design/development for their engines, say in early-1943, it would have taken them until early-1944 to get a Merlinized-Hookerized 1- or 2-stage supercharger in service in any numbers. The required logistics alone would have been a stumbling block for the introduction of the new designs, not overwhelming but significant.
What I mean by my statement "For the Germans, leaving out the fuel quality issue leaves engines that are pretty much equal to the US and UK engines in any operational sense, ..." is:
The DB 601/605 series filled the same niche as the Merlin for operational purposes when fitted to the 109 series airframe, and the BMW 801 and Jumo filled the same roll for the 190 series as the R-2800 or Allison. The engines may not have had the exact level of BMEP or boost that the Allied engines had but they still had enough performance to do the job.
"...at least until it no longer really mattered." means by the time the Germans could have gotten new engines and superchargers in service the war was already lost. In early-1944 it would not have made any significant difference if the Germans had the equivalent of a R-2800 in service (instead of the approximately R-2600 equivalent in the BMW 801).
By early-1944, the Russians in particular, but also the US and UK, had attritted the Germans to the point where they had 0% chance of winning the war. Starting in early-1944 the Germans could have had Me 38s, Bf 51s, FW 47s, and He Feuerspucken, (and the Russian equivalent best) and it would not changed the outcome of the war. It might have caused the war to drag on a bit longer, and caused more Allied fighter and bomber losses, but that is about it. The German pilots would still have been killed and there would have been thousands of up-to-date fighter aircraft sitting on the ground, just a little later - maybe in late-1945?
On the other hand, switching to the new engines/superchargers/aircraft models would have severely disrupted the numbers of 109 and 190 available during the changeover period, that disrupted period being from about late-'43/early-'44 to late-'44/early-'45. The disruption would have caused far more harm to German operations than the new engines/superchargers/aircraft models could possibly have helped.
The US would have face similar disruptions/delays (though probably not as severe) in production at a critical time for the Allied build-up/Lend-Lease. Would a Merlinized&Hookerized R-1820/R-1830/R-2600/R-2800/V-1710 in late-'43/early-'44 have made that much difference to the war effort? Would such engine/supercharger combinations have been worth the disruption in production?