The Spitfire MkI was not bad but could barely hold its own really, thankfully some geezer in the USA completely re designed engine and airframe and it managed to stumble along to the end of the war.
Most Overrated aircraft of WWII.....? (1 Viewer)
- Thread starter Lucky13
- Start date
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
The fact is it was a Rolls Royce engine manufactured under license.
Greg Boeser
2nd Lieutenant
The caption in this photo is describing the recognition features of a Merlin powered P-51 (B, C, D, K), vs an Allison V-1710 as used on the P-51, P-51A and A-36.
The fact is it was a Rolls Royce engine modified and re-dimensioned to accommodate US mass production tooling and techniques and manufactured under license.
Cheers,
Wes
With Rolls Royce approval because Rolls Royce were doing similar things in UK. The Twin boom Mustang did not have Rolls Royce engines because by that time the war had finished and the USA didn't want to pay the license fee. It is perfectly normal for a license built product to have changes made to allow for differences, the sub contractor may even suggest improvements but that doesn't change the fact that it is license built. The USA built some fantastic engines and aircraft, but didn't have a monopoly, just live with it.
I agree. I was just making the (somewhat nitpicking) point that, from a user standpoint, the engines were equivalent but not identical. Not trying to lay claim to the essential genius of them!
Cheers,
Wes
wuzak
Captain
Bollocks.
One of the biggest myths out there.
The fact is that Packard redrew the drawings because they had to change them....
....from 1st angle projection
to 3rd angle projection
Multiview projection - Wikipedia
As far as this statement, basically only prototype engines were built "in Rolls Royce's legacy craftsman UK shops". As production of the Merlin was ramped up and production was starting in other facilities (such as Ford UK), it could no longer be built by craftsmen. It was built in modern production facilities, properly toleranced so that parts need not be custom fitted.
Ford UK may have had their hand in setting the tolerances, but that was before Packard entered the frame.
Last edited:
wuzak
Captain
Considering that the P-51 used the SAE spline output shaft and the ones for the RAF used SBAC splines, it is not surprising that mods were required.
But note that Packard made many more Merlins with SBAC output shafts than they did with SAE shafts (ie for the USAAF).
Rolls-Royce Merlin
View attachment 515784
Rolls-Royce Merlin - Wikipedia
Packard V-1650
View attachment 515785
Packard V-1650 Merlin - Wikipedia
Spitfire XVIs were built on the same production line as the Spitfire IX for a while. The difference between them was essentially the factory from which the Merlin originated - the IX had a UK built Merlin, the XVI had a Packard built Merlin. There was no structural difference.
The Lancaster III was the Lancaster I with Packard Merlins. It had some extra switches in the cockpit, something to with the different carburetors. That said, Lancasters were known to have flown with a mix of engines from different sources - from Rolls-Royce, Ford UK and Packard.
British parts were interchangeable enough that they were used for spares for P-40Fs in North Africa. That they were built to different tolerances/custom fitted is another of the die-hard myths surrounding the Merlin.
There were differences. The carburetor was different. Two stage engines used a different supercharger drive system (epicyclic system designed by Wright). But not much else.
Gwaredd Thomas
Airman
- 38
- Aug 17, 2018
Agree!
Gwaredd Thomas
Airman
- 38
- Aug 17, 2018
While many of the Merlins' that were built for US the mechs had to do a bit of retrofitting. The best and first were built by the British. Correct?
At last - a definitive answer.
Old John Hamm was quite a guy, but it's possible his memory could have wandered a bit in the thirty five years since he was in England when I met him, or mine in the forty years since then.
Cheers,
Wes
I've read that UK-built Merlins generally outperformed US-built Merlins when installed identically in identical aircraft, but then I've read other sources saying that's hogwash. Wuzak, what's your take on this?
Cheers,
Wes
wuzak
Captain
I could not say whether the Packard built Merlins were better or worse than ones built at the several UK factories.
The performance was the same, however, give or take the differences between individual engines within acceptable tolerances.
Packard Merlins were built to the same ratings, which were developed by Rolls-Royce and type tested in the UK.
The Packard V-1650-1 was rated RM.3SM, same as all the 20-series Merlins.
The V-1650-3 was rated RM.8SM, same as the Merlin 63.
The V-1650-7 was rated RM.10SM, same as the Merlin 66.
The V-1650-9 was rated RM.16SM, same as Merlin 113 and 114 (used Mosquito PR.34).
There were slight variations, as the supercharger gearing was slightly different on the 2 stage engines.
Just a wee bit of an addition, it was Rolls-Royce who placed a Merlin in the Mustang first; the Mustang X trials machines were Mustang I airframes modified: Rolls-Royce Mustang Mk.X - Wikipedia
I was told a funny story by a member of the Rolls-Royce Heritage Trust who, when I mentioned that Packard always sent a wee tool kit over with every Merlin it supplied to the UK, said that R-R didn't supply tool kits with their Merlins because they didn't need them!
That's not strictly true. Right until the end of the war, pilots were advised never to dogfight a Zero, even though they were flying superior aircraft. In good hands, which admittedly weren't that prevalent in the IJN toward the end of the war, but there were still some, the Zero was a formidable adversary. People have regarded this simplistic view as fact from the comfort of their lounge chairs since the war, but at the time it most certainly wasn't the case.
I was told a funny story by a member of the Rolls-Royce Heritage Trust who, when I mentioned that Packard always sent a wee tool kit over with every Merlin it supplied to the UK, said that R-R didn't supply tool kits with their Merlins because they didn't need them!
That's not strictly true. Right until the end of the war, pilots were advised never to dogfight a Zero, even though they were flying superior aircraft. In good hands, which admittedly weren't that prevalent in the IJN toward the end of the war, but there were still some, the Zero was a formidable adversary. People have regarded this simplistic view as fact from the comfort of their lounge chairs since the war, but at the time it most certainly wasn't the case.
Last edited:
Well, the Packard Merlin may have been assembled stateside, but it was still a "foreign" engine, as it suffered from "NDH"(Not Designed Here), so of course it needed a tool kit!
Cheers,
Wes
Last edited:
Frankly my dears I do not give a damn, the simple fact is that no engine went out of a Packard factory in any way shape or form as an engine based on the Merlin without Rolls Royce approval, unless it was a completely different engine. I cannot understand how 75 years after the event we have so much flag waving nonsense. The P-51B/C and D series should be celebrated for what they were, a fine example of two nations doing their best to make the best. That is me being magnanimous, any discussion that veers towards the Packard Merlin being anything other than a license built Merlin may provoke a different attitude. The discussion always centers around the engine block when what was special about the Merlin was the supercharger.
Well the question has got to be asked. Why did Packard bother with Rolls Royce when they obviously knew much more to start with? I seriously would like to know? I am a patient man, and I feel I will need to be, please explain why Packard had to figure out how to produce a Merlin engine?
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
The A6M was still a serious threat right up to war's end, partiularly in the hands of pilots like Iwamoto, Nishizawa, Sugita, and so on.
The structure of the Zero was not "fragile", but rather a brilliant design that kept the airframe light, making the A6M's operational range unmatched.
In regards to the Merlin debate, the P-51B/C/K, P-40F/L, Spitfire XVI, Lancaster B.III and Mosquito B.VII all used the Packard Merlin and not the Merlin 28. But they were ALL the Merlin.
The only reason why there should be attention to the point, is that it does make a difference in the details just like when researching a Bf109E-4 that either had the DB601A or DB601N - it's simply a matter of detail.
The Packard was no better or worse than the Rolls Royce, but the U.S. at the time were masters of mass production, so it made sense to take advantage of that.
