TempestNutThe point about thread types on studs and fixings is a good one. There is no mention in the summary of all Rolls Merlin/Griffon engines in their ‘Aero Service Bulletin’ of 1950. Anybody have the definitive answer to this one?
It is hard to imagine the Americans building Merlins for Mustangs with BA, BSF & BSW threads.
Mark
Just found a reference to the threads. All Merlins and V1650s were produced with BA, BSF, BSW threads. Packard could not source its fasteners in the US so it decided to produce its own high quality fasteners. Source Graham White
TempestNutDo you know, stringbag, if the undercarriage was down when WG655 made the forced landing in the field?
From memory he bellied in and it was all was looking good for a while but the aircraft drifted towards a large tree and clipped it spinning it into another tree or something like that. I think the field may have been on a slope.
TempestNutI’ve always understood the Packard Merlins were re-drawn for American threads. This could cause problems with interchangeability on certain parts. However, I can’t find any references to it so it may have just been an assumption on my part.
I used to know an-ex RAF engine fitter who worked on both so he may have told me. He was also the only person I’ve ever known complain about the Packard Merlin – but he liked moaning so I never took much notice of that.
Packard Merlin’s used British threads. Popular misconception has it that Packard completely redesigned the engine. This is not true. They redrew the blueprints, as did Ford in Manchester. Apart from the interim 2 piece head on the 28 and the supercharger drive on the two stage engines they were mechanically similar. Design authority always stayed with RR. Packard was a licence producer, and developed a close relationship with RR, hence the success of the venture.
TempestNutGuys – I’m finding this a really interesting thread – and also continue to be amazed at the sheer volume of knowledge available on this forum.
I note various comments in posts above that suggest interchangeabilty, but this may only be in one-off non-operational circumstances (eg: post war racing).
So I’m left with a question – to what degree were engines and/or parts exchangable between the different manufacturers at operational level? I’ve heard of Lancs being fitted with mixtures of the two engines (3 of one, 1 of the other, etc.) – can anyone confirm that? But I also wonder whether you could swap parts between the engines, external parts like manifolds etc., and perhaps even internals?
many thanks, Gnome
In theory it was entirely possible to mix parts between Packard and RR engines. In practice A Lanc squadron would be all BI’s or BIII’s and a Spit squadron IX’s or XVI’s so it is difficult to say how much if any interchangability went on.
As I mentioned above the two manufacturers used differently sourced Ignition systems and carburettors. This would have caused some issues in cross fitting the engines in the field. On Packard Merlins for US aircraft such as the P40 (V1650-1) or P51 (V1650-3) the propeller shaft was different and in the case of the Mustang engines the reduction gear ration was different to the Spitfire, not withstanding that the Core of say a V1650 – 3 was the equivalent of a Merlin 61. V1650 engines had different accessory drives to suit the aircraft requirements and it would not have been practical for these engines to interchangeable.
The 100 series V1650 – 9 for the Mustang that is used in the racing Merlins were nearly all Post war engines.
TempestNutTempestnut.
Well it was rhetorical question and of course Bedford sunk themselves…but under American management.
A good read is ‘On a clear day you can see General Motors’. Although thinly disguised it was surely by John DeLorean.
Mark
(formerly on the GM project management engineering team of the Bedford Military TM. Still giving sterling service in the Gulf, I presume,… and with a British engine.)
Mark point taken, and I’m not in anyway trying to defend anything here. I have had plenty of experience of “well it works in the mid west and it works in the Rockies so it should work here” However occasionally the company culture allows you to fight your corner and get things right. My father experience a good deal of “well it works in the Alps so it must be your drivers” from a nameless manufacturer not far from the Alps. They had to suffer the ignominy of eventually removing new parts from newly assembled vehicles and replacing them with durable American parts, before anyone would purchase them. Not a situation that sat well with them but very amusing to witness.
Getting back to aviation the story of Wright Aeronautical is one of the most appalling around, and it sometimes beggars belief that the R3350 actually managed to get into the air at all, and that B29’s ever made it to Japan. It makes the woes of the Sabre look like a stroll in the woods. And it was management greed that created the crisis not lack of engineering skill, because eventually they were forced to get it right and we know what a strong engine it became. Same can not be said of Wright.
TempestNutDidn’t realise Merlins were built in Glasgow as well!
Need to check my references but I’m sure they built a lot of the fighter engines,
TempestNutOne year at Fairford, about 1987/88/89 it rained solidly all day. Had trouble seeing anything in the air
TempestNutAs an aside, Ford also completely re-drew the Merlin to much tighter tolerances. They said the original tolerances were far too loose for successful mass production. It took a year.
Source: Stanley Hooker – Not Much of an Engineer.
I think that most Aero engine manufactures had the same issue as RR prior to 1939. Up to this point parts were manufactured and if they were not quite right they had craftsmen on hand to make them fit. In this way they could build in quality.
This was never going to work in a mass production scenario, and companies such as Ford and Packard need to ensure that each part was identical, and completely interchangeable. This work benefited RR no end.
TempestNutJust wondering how many Merlins were built by Ford, Packard and Rolls-Royce – does anyone know the production figures?
Total Production 168,040
Derby 32,377
Crew 26,065
Glasgow 23,647
Ford Manchester 30,428
Packard 55,523 inc 800 odd produced by continental
TempestNut…and did the General Motors ‘Detroit Diesel’ engine, so beloved of the cheap fuel US haulage industry, sink Bedford Trucks in the UK with its low MPG figure?
Mark
Shaky ground here. Bedford sunk themselves. They fitted Cummins (an other US design) in their later heavy trucks which had the best fuel economy of any heavy duty engine, but it did not save them. I know as I prepared some of their vehicles for press test on behalf of Cummins, and it was frankly embarrassing.
TempestNutThere are numerous individual and unit accounts through out the war that point to their experiences being in favour of one or other of the Packard or RR engines. On balance it usually came down to the mod level. Around 50,000 Merlin’s were rebuilt during the war, and many XX’s rebuilt as 22’s etc. When collecting these accounts its often very difficult to get to facts to support the experience.
As an example its always been reported that the Spit XVI with this Packard Merlin 266 was more reliable than the Spit IX with the RR engine. This was often the case as even when the XVI was introduced in mid to late 44, most spit IX’s would have had a 61 or 63 engines. The 66 IX and 266 XVI had mods to make them stronger to take advantage of 150PN fuel. This would have occurred on a unit by unit basis so as to keep support as simple as possible, bearing in mind most frontline units were on the move during this period.
If the war had continued Spit VIII’s and XI’s would have been produced with a 100 series engines with a max boost rating of 30” and 2,200hp at low level on tap. These would have been potent fighters. This engine had been type tested and flown
TempestNutIf you read any of the authoritative accounts of the RR Merlin it is obvious there were very few differences between a Packard Merlin and a RR Merlin. RR manufactured more Merlin’s than anyone, without including the Ford production that nearly all when to Bombers. So as well as doing prototypes and mass production RR did all the short run Fighter engines, a much more demanding scenario than just mass production.
As mentioned above that the Packard Merlin used a different supercharger drive on its two stage engines. This was the only major mechanical difference.
Ignition systems and fuel systems were American sourced, but they were fundamentally the same. Initially Packard were able to introduce improvements into the Merlin earlier than RR as they were still in the set up phase early in the war. The best example of this was the two piece cylinder block. The first Packard the V1650-1 or Merlin 28 depending on the customer used a Packard designed 2 piece block well before RR. This engine was used mainly in Lancaster’s, and powered 617 squadron on the Dams raid. They were better than the Merlin XX that they were based on. Once RR had finalised its design all subsequence Packard Merlin’s used the RR design of two piece block the Packard Merlin 28 becoming a 38 and the XX a 22.
Co-operation between RR and Packard was excellent and a salutary lesson for all of today’s young budding and existing MBA’s . Much has been made of RR using craftsmen and Packard being more experienced in mass production but I don’t believe there is any substance in this, other than it makes a good story.
The racing Merlin’s in the US are incredible engines. They use a Packard bottom end based on the 100 series Merlin, with 500 or 600 series Transport blocks and heads. They use Allison connecting rods from the Allison that powered the P82, and have mods to the crank that counter the vibration from the heavier Allison rods. They run at up to 3200rpm and produce 3300hp plus.
TempestNutThere were concerns that aircraft noise from Stansted would block the move, but now it seems that since Stansteds second runway has been axed the plans will go ahead.
Another of John Prescott’s ideas of ‘affordable housing’ ? 😡
Denis As a “near Stansted resident” when was it decided to can the extra runway? I would be interested in this info as not many around hear know about this. 🙁 🙁
TempestNutMoggy a very good question and one I hope to be able to answer after I have finished Frederick Taylor’s reappraisal of the raids in the light of new material and meticulous research by some German historians. I quote from a review “Frederick Taylor’s well researched and unpretentious book is a robust defence of the Dresden raids that counters the recent attempts to recast the Nation that gave the world Auschwitz as the second world wars principal victims” Michael Burleigh, Guardian
So much of what we think we know about this raid comes from a work of Fiction. Somehow over the years more and more people have assumed that this represents the truth of the raid. Historians such as David Irving have incorporated parts of this Fiction into their historical books giving unwarranted credence to much of the misinformation.
Part of the horror that has been portrayed comes from the fact that less than three months after the raid Dresden was in the hands of Stalin and it suited his purpose to feed misinformation out about the raid. After all it was the Russians that were desperate for the RAF and USAAF to bomb Dresden so that they could stem the flow of troops east, and civilians west.
One thing is for sure, If the RAF had been able to concentrate their raids as accurately as they did this night one year earlier during the Battle of Berlin, Harris just may have realised more of his aims. Those that took part in this raid should look back with pride that they had executed a text book operation on a legitimate target that certainly contributed to saving allied lives.
TempestNutTry this site it will keep you going for the next year as you learn all about Hawkers finest with a bigger prop even than the Corsair.
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