MiTasol
1st Lieutenant
for the aircraft following. How marvelous. In flight oil re-purposing. And environmentally friendly as well.
Which country designed the best engines for WWII?
- Thread starter Soundbreaker Welch?
- Start date
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Yes, they did laboriously hand lap the surfaces, and they were oil tight - only once.
As soon as they got out in the field and mechanics did what mechanics do, open up this hand fitted faces regularly, lever open faces with screwdrivers, they leaked like sieves for ever more.
It was a basic failing - Rolls Royce were not production engineering the engines as a mass market commodity.
Packard engineers took one look at a Merlin, burst out laughing and redesigned it like a car engine. Gang milled every surface and chucked a paper gasket in it, built them much faster, much cheaper and much easier to maintain.
Rolls Royce produced more Merlins than Packard. Do you have any evidence of the Packard being like a car engine? How many 27 litre 12 cylinder twin stage supercharged engines did American cars have?
Are you being deliberately obtuse?
Packard re-engineered the Merlin from a hand built engine to a mass produced engine with few hand finishing operations to be built on its car engine lines just like bigger car engines.
Of course RR built 'more' they were building them for far longer! 1936-1950 vs 1942-45
No they didnt. We have whole threads dedicated to this. You are suggesting that Rolls Royce and the UK government built factories to mass produce an engine using the same methods as those used to make the prototype and early production runs.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
Spindash64
Airman
- 85
- Oct 21, 2021
Honestly, there's not much point in putting minor powers into this competition: as impressive as some local designs might be, they couldn't keep up with other nations overall.
So for the Magnificant 7, from worst to best:
7: Italian. This one's a no brainer. They had some lovely aircraft designs and designers, but their industrial capacity was utter garbage. They had no real choice but to use German engines.
6: French. I know they had their run cut short, but even by prewar standards, their engines weren't particularly impressive. The Hispano V-12 engines get some kudos for managing to fit the heavy Hispano Suiza 20mm in a nose mount configuration, but otherwise it was simply okay at best
5: Soviets. While the M-82 is a fine engine, it and almost all other Soviet engines in service during WWII (and even in the Korean War) were based heavily on existing foreign engine designs. They made considerable improvements to the designs, make no mistake, but the lack of fully native engine designs to enter production belies a critical weakness in Soviet Aviation until the death of Stalin
4: Japanese. While understandably notorious for low engine power, Japanese engines often boasted either incredibly low weight or incredibly small frontal area for the power they provided, at least on such low octane fuel. The Homare Radial weighed only around 10% more than a 2 Stage Merlin engine, but with Water Injection offered comparable power at low altitude to a Merlin running 150 octane and 25lbs boost, while itself being limited to 87 octane, and also not needing the weight of a liquid cooling system. Of course, the Merlin has other advantages that put it ahead overall, but compared to the previous 3 nations, Japan actually had native designs that offered a handful of genuine advantages over their compatriots. It also bears mentioning that they successfully designed, built, and tested their first Turbojet engine having nothing more than a Cutout diagram of the BMW 003 to look at, a downright remarkable feat of engineering
3: German. Out of the axis nations, Germany delivered the most consistently powerful engines. While power output was limited by a lack of 130 octane fuel or better (the synthetic C3 proved too slow to evaporate to allow running rich enough mixture to act as a 130 octane fuel), they were one of the few nations to adopt Water-Methanol injection to boost performance during the war, helping to close the gap slightly. The DB engines also had multipley variable speed superchargers that largely eliminated "deadspots" found on 1, 2, or even 3 speed superchargers. However, the complicated designs proved difficult, if not impossible, to construct reliably by the end of the war, which is part of why they were quick to move to Turbojet powered designs: engine life had degraded to the point that even the 25 hour lifetime of a Jumo 004 wasn't that much worse of an investment for its production time and cost than a Jumo 213
2: American. I wasn't sure whether to put them in first or second, but ultimately decided to just barely leave them with the silver. The R-2800 was a truly excellent engine, and the US not only had access to the best fuel of any nation overall throughout the war, but they were relatively quick to make use of Water Injection, and were the world leaders in both turbocharger development and early 2 stage supercharging. The reason they lose the gold should be obvious when we move their, however
1: British. I'm sorry, the Merlin is just TOO good for me to put Britain anywhere but Gold. This was an engine from just before WWII that managed to survive the war with surprisingly few internal changes, yet still going from around 900hp on early Merlin IIIs to more than 2,200hp on the V-1650-9, with a weight increase of only around 100kg. This was an engine that was shoehorned into almost any plane that had merlins available to use: Spitfires, Hurricanes, Kittyhawks, Lancasters, Barracudas, Mustangs… for crying out loud, even post war G.55s and Spanish 109s were retrofitted with Merlin Engines. The Merlin was an absurdly versatile design, with a simple change of supercharger and fuel quality often being enough to provide a tremendous increase in power under the needed conditions. While the US V-1710 was far from bad, the slower introduction of 2 stage supercharging meant the Merlin pulled ahead in late 1942 and never looked back
And this wasn't even the only engine design Britain had as a winner: the Griffon engine was a marked increase in displacement with only a small increase in size, and the Napier Sabre, for all its woes, DID eventually offer excellent power for its frontal area, comfortably reaching 2,500hp on the Tempest Mk V
So for the Magnificant 7, from worst to best:
7: Italian. This one's a no brainer. They had some lovely aircraft designs and designers, but their industrial capacity was utter garbage. They had no real choice but to use German engines.
6: French. I know they had their run cut short, but even by prewar standards, their engines weren't particularly impressive. The Hispano V-12 engines get some kudos for managing to fit the heavy Hispano Suiza 20mm in a nose mount configuration, but otherwise it was simply okay at best
5: Soviets. While the M-82 is a fine engine, it and almost all other Soviet engines in service during WWII (and even in the Korean War) were based heavily on existing foreign engine designs. They made considerable improvements to the designs, make no mistake, but the lack of fully native engine designs to enter production belies a critical weakness in Soviet Aviation until the death of Stalin
4: Japanese. While understandably notorious for low engine power, Japanese engines often boasted either incredibly low weight or incredibly small frontal area for the power they provided, at least on such low octane fuel. The Homare Radial weighed only around 10% more than a 2 Stage Merlin engine, but with Water Injection offered comparable power at low altitude to a Merlin running 150 octane and 25lbs boost, while itself being limited to 87 octane, and also not needing the weight of a liquid cooling system. Of course, the Merlin has other advantages that put it ahead overall, but compared to the previous 3 nations, Japan actually had native designs that offered a handful of genuine advantages over their compatriots. It also bears mentioning that they successfully designed, built, and tested their first Turbojet engine having nothing more than a Cutout diagram of the BMW 003 to look at, a downright remarkable feat of engineering
3: German. Out of the axis nations, Germany delivered the most consistently powerful engines. While power output was limited by a lack of 130 octane fuel or better (the synthetic C3 proved too slow to evaporate to allow running rich enough mixture to act as a 130 octane fuel), they were one of the few nations to adopt Water-Methanol injection to boost performance during the war, helping to close the gap slightly. The DB engines also had multipley variable speed superchargers that largely eliminated "deadspots" found on 1, 2, or even 3 speed superchargers. However, the complicated designs proved difficult, if not impossible, to construct reliably by the end of the war, which is part of why they were quick to move to Turbojet powered designs: engine life had degraded to the point that even the 25 hour lifetime of a Jumo 004 wasn't that much worse of an investment for its production time and cost than a Jumo 213
2: American. I wasn't sure whether to put them in first or second, but ultimately decided to just barely leave them with the silver. The R-2800 was a truly excellent engine, and the US not only had access to the best fuel of any nation overall throughout the war, but they were relatively quick to make use of Water Injection, and were the world leaders in both turbocharger development and early 2 stage supercharging. The reason they lose the gold should be obvious when we move their, however
1: British. I'm sorry, the Merlin is just TOO good for me to put Britain anywhere but Gold. This was an engine from just before WWII that managed to survive the war with surprisingly few internal changes, yet still going from around 900hp on early Merlin IIIs to more than 2,200hp on the V-1650-9, with a weight increase of only around 100kg. This was an engine that was shoehorned into almost any plane that had merlins available to use: Spitfires, Hurricanes, Kittyhawks, Lancasters, Barracudas, Mustangs… for crying out loud, even post war G.55s and Spanish 109s were retrofitted with Merlin Engines. The Merlin was an absurdly versatile design, with a simple change of supercharger and fuel quality often being enough to provide a tremendous increase in power under the needed conditions. While the US V-1710 was far from bad, the slower introduction of 2 stage supercharging meant the Merlin pulled ahead in late 1942 and never looked back
And this wasn't even the only engine design Britain had as a winner: the Griffon engine was a marked increase in displacement with only a small increase in size, and the Napier Sabre, for all its woes, DID eventually offer excellent power for its frontal area, comfortably reaching 2,500hp on the Tempest Mk V
wuzak
Captain
The only hand fitting at Rolls-Royce facilities was for prototypes.
Ford UK also built Merlins. Are you suggesting they also performed hand fitting operations?
A number of British built Merlins were broken down to use for spare parts for V-1650-1s in North Africa. The British "hand-built" components would fit into American "precision machined" engines without issue. How is that possible?
The bulk of British Merlins built were from 1940 to 1945. About 50% more time for around 100% more engines.
Pretty sure Packard Merlins never went anywhere near a car engine line. Instead they were manufactured in purpose built facilities.
The first jobs Packard did with the Merlin was to convert the drawings from 1st angle to 3rd angle, and to develop the connections from the head to the block for the water passages - Packard did not build the earlier single piece block/head style Merlin, making the 2 piece block from the start (Rolls-Royce developed the 2 piece block but had not yet finalised a solution for the water connections. Packard developed a system for initial production, but later changed to the Rolls-Royce system).
wuzak
Captain
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
What "bigger car engines"?
The Packard "Twin Six" (which was the first V-12 engine) by 1932 was 540 cubic inches with 160 hp.
Yes, the twin six spawned Liberty engines during WWI, but it's automotive V-12 was NOT even close to an aircraft engine.
The Lincoln Zephyr (a Ford division) had V-12 engines: 267 cubic inch, 292 cubic inch and 306 cubic inch - not even close to the needs of a WWII fighter.
Cadillac's V-12 was 368 cubic unches at 160hp.
Auburn's V-12 was a 390 cubic inch Lycoming engine.
Cadillac's V-16 was 452 cubic inches at 165hp.
NO automotive engines were comparable to a fighter engine. Do not make the mistake of comparing the two.
MiTasol
1st Lieutenant
Ignore this oxygen stealer
He never has, and probably never will, actually work on Merlin or Kestrel or any other older RR engine, unlike a significant number of members here. He has never read an actual genuine technical document relating to overhauling or manufacturing Merlin's or earlier Rolls engines like the Kestrel or he would not make such moronic statements.
Hand scraping at RR went out with the prewar bearings. Don't waste your time and energy on him.
He never has, and probably never will, actually work on Merlin or Kestrel or any other older RR engine, unlike a significant number of members here. He has never read an actual genuine technical document relating to overhauling or manufacturing Merlin's or earlier Rolls engines like the Kestrel or he would not make such moronic statements.
Hand scraping at RR went out with the prewar bearings. Don't waste your time and energy on him.
I have seen most of what he posted in an article about the Packard Merlin, it is a masterpiece of misdirection, omission and distortion, mostly based on something Cyril Lovesey said.
An infernal combustion engine is just an engine - the methods of manufacturing them is common.
Rolls Royce hand built their car engines using exactly the same laborious hadn't scraping and fitting methods as they built their aero engines.
Packard? They were a good generation ahead and applied proper engineering principles and processes to building engines.
Engineering 101: If you have to hand fit a part, you didn't make it right.
US engineers implicitly understood that truism.
wuzak
Captain
Hand fitting is quite fine for very small runs of engines. Like prototypes. Pretty much where Rolls-Royce used those techniques.
Everyone relax. Lets not start resorting to personal attacks.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
"Hand fitting" was a hallmark of a finely crafted luxury automobile.
Rolls Royce, Duesenberg, Bentley, La Salle and such were all built one vehicle at a time, from the chassis up - however, the engines provided for these autos were not.
Rolls Royce had been manufacturing military aircraft engines since 1915, they were familiar with assembly line manufacturing.
Assuming that a vine-covered little cottage somewhere out in the country that had a half dozen craftsmen laboring away over engines on a stand, looking through their bifocals as they carefully shaped the engine and components by hand is an absurd notion.
For some reason, people have come to accept the myth that Packard "modernized" the Merlin's manufacturing process but fail to realize that Rolls Royce had been providing Merlin engines to the British military in large numbers long before Packard and Continental started production in North America.
Rolls Royce, Duesenberg, Bentley, La Salle and such were all built one vehicle at a time, from the chassis up - however, the engines provided for these autos were not.
Rolls Royce had been manufacturing military aircraft engines since 1915, they were familiar with assembly line manufacturing.
Assuming that a vine-covered little cottage somewhere out in the country that had a half dozen craftsmen laboring away over engines on a stand, looking through their bifocals as they carefully shaped the engine and components by hand is an absurd notion.
For some reason, people have come to accept the myth that Packard "modernized" the Merlin's manufacturing process but fail to realize that Rolls Royce had been providing Merlin engines to the British military in large numbers long before Packard and Continental started production in North America.
buffnut453
Captain
Please answer these 2 fundamental questions:
1. How many Merlins did Rolls Royce make in the UK compared to Packard in the US?
2. How did Rolls Royce establish new factories across the UK to ramp up production after 1939 (long before Packard even SAW a Merlin), which included engaging Ford to make Merlins in the UK, while using a relatively skilled workforce to hand-fit each part?
Bottom line: Rolls Royce made more than double the number of Merlins compared to Packard. Please explain how this was done using low-rate production techniques prevalent in the luxury car business.
Only if they are produced in large numbers. Packard demanded a minimum order of 5,000 to tool up for mass production. Rolls Royce only produced 5,050 Kestrel and Peregrine engines from 1926 to 1940, you would not use mass production methods for that rate of production. The Merlin, Spitfire and Hurricane only became mass produced because war was declared when it was. All three were scheduled to be replaced by Vulture and Sabre engines and aircraft designed for them, like the Typhoon Tornado Halifax and Manchester. The decision to mass produce the Merlin and stop the RR Vulture and Peregrine was taken around the time that the British were approaching Packard and others to have Merlins made in USA. Work on the Crewe factory started in 1938 production started at low volume in 1939. Work on the Glasgow factory started in 1939 with production of 200 /month by 1941 eventually 23,675 were produced all in house. The Ford Manchester factory was completed in 1941 and produced 30,000 engines
