Packard vs. Rolls-Royce

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19 years 4 months

Posts: 18,350

Apologies if this has come up before!

On my desktop calendar, it is claimed that the Packard Motor Company built better Merlins than RR.

Can any operators/pilots/restorers back this up? :confused:

Original post

Member for

22 years 11 months

Posts: 4,169

Packard simplified the Merlin for mass production. There seem to be many differences between the two engines. Of course if you have a Mustang then a Packard is much better.....

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19 years 1 month

Posts: 4,674

The external differences between Packard and RR built engines were supercharger drive gearing, as well as accessories such as magnetos and carburettors. I have to do a little data mining on the internal differences but I think they were rather minor.

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18 years 6 months

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Somewhere around here I have an excellent tome on the Lancaster, but we're in mid-renovations so it can't be found. I remember a discussion about this in the book, may or may not have had something to do with being a BI or BIII. But anyway one thing I do remember clearly is the comment that the Packard engines came complete with a magnificent toolkit that was much appreciated by the erks - who therefore preferred the Packard engine!

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18 years 8 months

Posts: 506

I think it is in Alex Henshaws book, where he describes the skew gear failures that used to happen occasionally on the RR Merlins, apparently the Packards didn't suffer from the same problems.

read an article on Packard cars which suggested that RR Merlins had a shorter lifespan than the Packards too.

I hate to think anything might top the Rolls Royce product, but it might actually be true...

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19 years 8 months

Posts: 2,108


I hate to think anything might top the Rolls Royce product, but it might actually be true...

I would be surprised that the Packard units weren't of a higher quality given the circumstances.
Packard had the knowledge of quality mass production techniques, and a ready access to the required raw materials and on top of all that their production facilities weren't subject to the possible disruptions as a result of having the odd bomb thrown at them......... :rolleyes:

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22 years 11 months

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In Warbirds WorldWide, issue #18, there is an article named Reinventing, not Fixing which discusses the differences.

1) The engine was totally redrawn. Rolls-Royce drawings were in 1st angle of projection compared to the Packard drawings which were in 3rd angle of projection. This can be put down to the lack of international standards.

2) Rolls-Royce had an apprentice system which trained the personnel to become skilled fitters. How tight a bolt should be fitted was done "on the feel". Packards mass production lines didn't allow this and they specified each nut and bolt on the drawings with the correct torque.

3) Roll-Royce maintained parts interchangability between different marks which necessitated the use of adapters. When Packard redesigned the engine, they adapted it for the use of american accessories and completely broke the interchangability.

4) Materials used in the engines were also to a non international standard. Packard had a hard time duplicating the nitriding steel for the crankshaft, a material superior to anything the americans had. On the other hand some of the aluminium castings were improved by developing an improved alloy.

Only a few samples, the whole read in WW #18.

Christer

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19 years 2 months

Posts: 74

From "The Merlin in Perspective - The Combat Years" By Alec Harvey-Bailey (Roll Royce Heritage Trust):

The author indicates the differences were the supercharger drives (RR - Farman, Packard - epicyclic gearing), magnetos and carburettors.

On the supercharger drive, a couple of the old timers at work relate the story that RR did not give details to Packard regarding the (superior) Farman drive as the US would not share its fuel injection technology. Anyone else heard that one?

Finally the Smithsonian magazine ran an article last year about the men who rebuild these engines in the US, predominately for air racing. They all indicate the a Packard crank and block with the rest being RR is the best combination. Unfortunately they interviewed a nutter in the article who stated that the reason the RR Merlins had more parts was that the British were Socialists!

- Hamtech.

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19 years 8 months

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Unfortunately they interviewed a nutter in the article who stated that the reason the RR Merlins had more parts was that the British were Socialists!

:eek: :eek: :mad: :mad:

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19 years 2 months

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Actually, that's not so off the wall. If for 'socialists' you read 'factories full of people handbuilding engines in a full union rather than real mechanised mass production' :D

Bristol was the same.

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19 years 4 months

Posts: 474

If 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.

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22 years 11 months

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I'm not in a position to really argue this, however I have been shown quite a number of engineering differences between Rolls Royce and Packard during the rebuild of both types.
Some tooling between the two types is different as well.

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19 years 2 months

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Hi TN,
Good post. I can't agree with the thesis however, though the point about 'a good story' driving what is highlighted is well made.

Warbirds Worldwide Iss 18's article was an excellent view of these differences. Worth getting hold of if you can.

Going back to the original question, 'better'? Hmmmm. Daz - was you callendar a US origin product perchance? :D
Cheers

Member for

19 years 4 months

Posts: 474

There 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

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19 years 4 months

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Hi TN,
Good post. I can't agree with the thesis however, though the point about 'a good story' driving what is highlighted is well made.

Warbirds Worldwide Iss 18's article was an excellent view of these differences. Worth getting hold of if you can.

Going back to the original question, 'better'? Hmmmm. Daz - was you callendar a US origin product perchance? :D
Cheers

That might account for the distinct lack of Spitfire porn!! :rolleyes:

TN, thanks for that info.

Member for

22 years 11 months

Posts: 10,029

Ford build the Focus car in the US.

It has been adapted by the Americans to suit their market, a change here, a change there, to the point where there is little if any interchangability between the the European and US versions.

The US version has low reliability and high warrenty costs.

The Focus in Europe, not withstanding the new model just released, has been a fantastic success.

Some times 'Uncle Sam' does not always know best.

Mark

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19 years 8 months

Posts: 2,108


Some times 'Uncle Sam' does not always know best.

Absolutely.
The car that came bottom of 140 odd in the recent Top Gear survey was the M-class Mercedes-Benz.......and where is that made...hmmm....in the Merc factory over t'other side of pond.
It's interesting that the standards of restoration in the USA is so high in terms of cars and thing like hot rod building etc., and of course warbirds etc., :D but every US built car I've ever been in (quite a lot) have been appalling in terms of quality.
But they are cheap...... :rolleyes:

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22 years 11 months

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...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?

I think so. :(

Mark

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19 years 3 months

Posts: 222

Just wondering how many Merlins were built by Ford, Packard and Rolls-Royce - does anyone know the production figures?

Member for

19 years 4 months

Posts: 474

...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.

Member for

19 years 4 months

Posts: 474

Just 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