Merlins > Packard vs RR

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Hello PBehn,

I was actually hoping to get a more thoughtful response from you of all people.
I really wasn't discussing the quantities of production by each company but more a matter of design choices with an expectation of production quantities. If you look at even modern low production engines, there were a bunch that were NOT built on production lines but by small teams. The product is higher quality but the product is much more expensive and production numbers are low.
The accounts that I have read state that tolerances were looser with Rolls Royce because parts were expected to be fit to each engine and that Packard did not work in that way and needed tighter tolerances to guarantee parts interchangeability.
Are you telling me this is NOT true?
If not, then what is the truth? I don't know more than what I have read and heard in interviews.
The problem with reading what has already been posted here is that quite a lot contradicts with other sources.
Which sources are to be trusted?
Read this thread, then when you have read all of this thread state that you have read all of this thread and absorbed the detail within it. You are trusting sources that claim the British in their mud huts machined thousands of pistons and cylinders then started to measure them to see which could be used to fit one another. It is an insult to anyones intelligence but it suits your PACKARD flag waving exercise. The truth is Packard were the main contractor, to sub contract they needed drawings, in the USA all drawings were in third angle projection and so to avoid any errors all drawings were produced by Rolls Royce in third angle projection so that any problems resulting would be down to Packard not Rolls Royce. That is just international engineering business not a statement of different quality standards. Before the Lancaster was produced in Canada all drawings had to be copied and supplied to Canada for the Canadians to work with, that is how you build things in an engineering project, with drawings. Yes I am telling you it is not true, first you produce your accounts of what you believe to be true, it is a myth. The Rolls Royce Merlin engine was an engineering product, there weren't Packard and Rolls Royce versions except in minor detail because it was a Rolls Royce engine built under license by Packard.
 
The truth may be somewhere in between.
However it may have been the men at Ford of England who production engineered the Merlin and not Packard. Ford of England in this case having very little to do with Ford of America.
Ford of England had changed the tolerances (tighter) and gone to more fully interchangeable parts in the shadow factory they ran. This work started almost a year before Packard got involved. Ford of England built over 30,000 engines by VE day and over 32,000 engines total by 1946. They built more engines than the RR Derby factory. This changes a bit depending on author or article.
RR themselves had the Derby factory, the Crewe factory and the Glasgow factory. Nobody has ever claimed that the british built engines, despite being built in 4 different factories didn't have interchangeable parts, ar least not anymore than R-1830s built by Chevrolet, Buick and P&W didn't have interchangeable parts.

The British factories did specialize a bit with one factory making single speed engines and another 2 speed engines but the US did the same thing with some US companies making single speed or single stage R-2800s and another company making only two stage engines.
Development work was centered at Derby due to the higher skilled work force but both Crewe and Glasgow were planned around using lower level or lower skilled employees to assemble the engines.

The idea that Packard Stepped in and saved the day by showing RR how to mass produce the Merlin is a persistent myth with little basis in fact.

The Merlin may have been designed with many more parts than an allison but the vast majority of extra parts were fasteners. This may have been due to differences in American and British gaskets, surface finish/flatness and design practice. This is a guess. Ability to build in large quantity large parts with the required flatness and stiffness to use a minimal number of fasteners may have changed or been different in the two countries.
The US stayed with cast cylinder heads on radials for a number of years after Britian changed to forged heads because the US companies could get better castings from their suppliers than Bristol in England could get from British foundries for example. It doesn't matter what you can design or specify if you can't actually produce it in numbers given your sources of supply/subcontractors.
 
The Merlin may have been designed with many more parts than an allison but the vast majority of extra parts were fasteners. This may have been due to differences in American and British gaskets, surface finish/flatness and design practice.

I think it came from Rolls Royces automotive background of a RR never breaks down it just occasionally fails to proceed. Early cars often just fell to bits on the road and Henry Royce designed vehicles were noted for finishing journeys with the same number of parts as it started. We know a bolt can fail but when you have 31 of them the other 30 will get you home
 
In 1943 production of Meteor tank engines was falling behind the Armys needs because of lack of factory space and machine tools and no drop in the production of Merlins could be allowed. Time expired or damaged Merlins were stripped and thoroughly checked and the parts used to build Meteors. For example a crank for a Spitfire engine was not allowed to exceed more than 250 hours but the same crank could be used in a Meteor for another 600 hours. Merlin crankcases often cracked when the plane crashed but the cases could be welded and reinforced and reused in a Meteor.

The Merlin engines that were reused came from all factories and when a crank was reused it was no longer a Ford or a Packard or a Derby built crank it was simply a Meteor crank with no discrimination or mention of origin on the service sheet.
 
Cranks of the Meteor were making 2600 rpm vs. 3000 rpm on the Merlin, while the engines itself never have had boost of any type. Thus less power than Merlin, but also much less of stress on engine parts.
 
Cranks of the Meteor were making 2600 rpm vs. 3000 rpm on the Merlin, while the engines itself never have had boost of any type. Thus less power than Merlin, but also much less of stress on engine parts.

Exactly....

2,550 rpm for the Mark IVB in fact (ex-Centurion tank driver in the distant past) :salute:

.....and I don't remember any instances of failure or even leaks.
They were good for 4,000 track miles or seven years (TBO of AFV "A" vehicles with Brit Mil).
 

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Packard Merlins, which powered the Lanc X, gave only about 82% of the power of the equivalent Rolls Royce Merlins, and that crews would practically kill to get the RR Merlin
A peacetime story, but this reminded me of an event in 2014 when Canada's Packard-powered Lancaster suffered catastrophic engine failure whilst on a tour of the UK, and had to borrow a RR Merlin from the RAF heritage flight. The RAF mechanics were able to fix the Packard engine before the Canadian flew home, but it cost CAD $180K.

Engine failure strands Lancaster bomber in Britain

https://www.cbc.ca/news/canada/hami...r-ends-with-180k-engine-repair-bill-1.2774375
1571782235220.png
 
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A peacetime story, but this reminded me of an event in 2014 when Canada's Packard-powered Lancaster suffered catastrophic engine failure whilst on a tour of the UK, and had to borrow a RR Merlin from the RAF heritage flight. The RAF mechanics were able to fix the Packard engine before the Canadian flew home, but it cost CAD $180K.

Engine failure strands Lancaster bomber in Britain

https://www.cbc.ca/news/canada/hami...r-ends-with-180k-engine-repair-bill-1.2774375View attachment 557727
It was "Stranded" at my local airport Teesside. This was Middleton St George airfield during WW2 and the home airport with nearby Croft of Mynarski who the Mynarski Lancaster is named after. It did a few shake down flights before leaving and flew over my mothers house as we set off to attend her brothers funeral, He was an RAF veteran invalided out of BC air ops early in the war. Lancaster leaves after engine repair
 
You can find several ratings for a Packard V-1650-3 and V-1650-7. I have seen the V-1650-3 rated at 1,280 @ 3,000 rated power and 1,600 Hp @ 3,000 max ... and I have also seen the V-1650-3 rated at 1490/1670/1700 ... depends on where you find the ratings. Similar for the V-1650-7, different ratings.

But there was NO Rolls-Royce equivalent to the V-1650-3 or V1650-7. They were Packard engines with different parts than any Rolls Royce engine. Some could be interchangeable, but that was mounting, not internals.

On the other hand, a Merlin 224 is just a Merlin 24 built by Packard (the 200 part), and it has the exact same ratings for either manufacturer, regardless of the carburetor or other parts fitted. I have been around warbirds for a good number of years and have never heard of U.S. Merlins being called "weak" in any way, shape, or form. Neither have I heard of Rolls Royce Merlins being called same.

I HAVE heard that U.S. engines have much better parts interchangeability. Heard that for 20 years, and then someone in here said Rolls Royce fixed that issue rapidly and, by the end of the war, their parts were also interchangeable. I have never been able to confirm that in action because the active warbirds I know about usually have Packard-built Merlins in various states of parts mixes, usually with transport heads, sometimes new-production pistons and rings, and sometimes modern ignition systems. Basically, they are hybrids.

But, back in the 1960s and 1970s, the warbirds community in the U.S.A. generally wanted Packard Merlins. No doubt the warbird community in the UK wanted British Merlins. Also no doubt, this was very likely due to there being more parts of the home-grown variety being generally available than parts from the other country. I have never heard anyone with either a Packard or a Rolls Royce being particularly dissatisfied with their Merlin, provided it was properly overhauled last time around.

When it comes to racing, EVERYBODY complains when they blow an engine that was manufactured 50 - 70 years ago at 1,600 Hp but has been modified to produce 3,000 + HP. They usually complained about the hit to the wallet, not about why it blew.

About the post above, $180K is NOT a bad price for a "fixed" Merlin, depending on what was wrong. I have seen a complete overhaul of an old Merlin go for $250k. Depends on what needs to be reworked and replaced. Parts ain't exactly "cheap."
 
When Britain moved to Griffon production did the US show any interest in a Packard version?

Imagine a P-38 Lightning with Griffons. Mind you, the postwar Hornet used Merlins instead of Griffons.
Britain never really did move to the Griffon, there were 8,000 produced but in 50 variants mainly for the late model Spitfires and the Shackleton.
 
Britain probably WOULD have moved to the Griffon had piston engines not been being supplanted by jet engines. I think the Griffons came at EXACTLY the wrong time in history to have made a mark in the aviation world similar to the Merlin simply due to the timing of jet development.

Personally, I'd have wanted a Griffon that turns the other way ... but that's me.
 
Britain probably WOULD have moved to the Griffon had piston engines not been being supplanted by jet engines. I think the Griffons came at EXACTLY the wrong time in history to have made a mark in the aviation world similar to the Merlin simply due to the timing of jet development.

Personally, I'd have wanted a Griffon that turns the other way ... but that's me.
In terms of its most famous uses the P-51, Mosquito and Lancaster probably wouldn't have been greatly improved with a Griffon without making them new planes.
 
In terms of its most famous uses the P-51, Mosquito and Lancaster probably wouldn't have been greatly improved with a Griffon without making them new planes.
But the Fairey Barracuda suffered, reminding us that the Griffon was intended for the FAA. The postwar Griffon-powered Barracuda was significantly improved over the Merlin model.
 
Does anyone seriously believe that Rolls Royce manufactured nearly 84,000 Merlins by hand? That by the way matches the number that Ford and Packard produced together.

For the first half of WWII Roll Royce manufactured more large aircraft engines than any other manufacturer in the world. They had produced over 23,000 Merlins by the end of 1941. By aircraft engine standards this is mass production. At this point it one of the most widely produced engines of all time, exceeded only by the Hispano V-8 of WWI. In fact, this is a greater number than that marvel of mass production, the Liberty. By the of 1941 Packard had manged to produce 45. Rolls Royce reached it peak capacity the next year and produce ~ 18,000 in each of 1942,1943 and 1944. The idea that Packard taught Roll Royce how to build Merlins is obviously nonsense. As a point of reference Merlin production exceeded the combined production of Pratt & Whitney's R-1830 and Wright's R-1820 up until the end of 1941.
The Rolls Royce Merlin annual production totals had increased by a factor of ten within 4 years. There is no way that such a massive increase could be accomplished by so called" file and fit" methods. In addition, the new factories at Crew and Glasgow were located in areas that were not populated with a supply of skilled craftsman.
The following is from the book Rolls Royce Hillington Portrait of a Shadow Factory
Personnel Employed at Rolls Royce Aero Engine Factories
1935 7,835
1939 12,500
1941 38,600
1943 55,640
1944 57,067
Obviously, they could not possibly be training enough skilled workers to meet those numbers
Its interesting to note that almost ½ of them worked at Hillington. Hillington produced virtually every component (98%) in house and provided components to the other factories including Ford.
"Of the 25,000 Rolls Royce employees, 37% were female, and only 7% were manually skilled tradesmen, and including supervision and management the total skilled constituent never exceeded 12%."

It should also be noted Packard was not a mass producer of automobiles akin to Chevrolet or Ford. In fact, they were more comparable to Rolls Royce. Both started out as manufacturers of the world's finest automobiles. Like Rolls Royce, Packard expanded into aircraft engines, unfortunately, they failed in this endeavor. When sales of luxury cars declined after WWI, Rolls Royce introduced a lower priced car to boost production, but more importantly began to concentrate on aircraft engines such that by the time of the great depression they had become an aircraft engine manufacturer with a side line in luxury automobiles.
Packard did not have that option so in 1935 they introduced a downmarket 8-cylinder car. They had a fair bit of success with that and decided to go further downmarket in 1937 with a 6-cylinder car. They were going into the upper middle-class segment dominated by Buick. 1937 was the peak of Packard production with 123,000 units produced that year. I have always wondered about that number because it is double that of the preceding year as well as the succeeding year. Suffice to say that 123,000 units a year is no where near the 942,000 Fords, the 815,000 Chevrolets and 566,000 Plymouths produced in 1937.
Packard continued to make small numbers of hand built automobiles. Supposedly they employed as many workers in the luxury section as they did in the lower price lines. Packard still had a very large force of skilled workers.
 
Canadian Car and Foundry manufactured 1,451 Hurricanes between 1938 and 1943. I wonder if those nearly 1,500 Merlins were all sourced from Britain or if CC&F switched over to Packard Merlins by the end.

As a side note, until I saw this pic below I had no idea we also produced Sea Hurricanes.

14845626239_590569e6b7_b.jpg


With CC&F being located on the US border, the logistics of getting Merlins from Packard would have to be easier. Though I suppose the convoys from Britain come back mostly empty. By 1942 Victory Aircraft near Toronto, Canada was already producing Packard-powered Lancasters.
 
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You can find several ratings for a Packard V-1650-3 and V-1650-7. I have seen the V-1650-3 rated at 1,280 @ 3,000 rated power and 1,600 Hp @ 3,000 max ... and I have also seen the V-1650-3 rated at 1490/1670/1700 ... depends on where you find the ratings. Similar for the V-1650-7, different ratings.

But there was NO Rolls-Royce equivalent to the V-1650-3 or V1650-7. They were Packard engines with different parts than any Rolls Royce engine. Some could be interchangeable, but that was mounting, not internals.

The V-1650-3 was equivalent to the Rolls-Royce Merlin 63.

The V-1650-7 was equivalent to the Rolls-Royce Merlin 65/66. It was also manufactured as the Merlin 266 for British use (eg in the Spitfire XVI).

The main differences between the V-1650-3 and -7 and the British equivalents was the prop shaft (SAE spline vs SBAC spline), supercharger drive (epicyclic on Packards vs Framan type on Rolls-Royces) and a US supplied injection carburettor.

Some other small changes were made, including different bearing materials.

The internals were completely interchangeable. As evidenced by Rolls-Royce engines being broken down to be used for P-40F spares in North Africa.


On the other hand, a Merlin 224 is just a Merlin 24 built by Packard (the 200 part), and it has the exact same ratings for either manufacturer, regardless of the carburetor or other parts fitted. I have been around warbirds for a good number of years and have never heard of U.S. Merlins being called "weak" in any way, shape, or form. Neither have I heard of Rolls Royce Merlins being called same.

Almost all Packard Merlins used the same ratings as their British equivalent.

The two stage versions varied a little, as the gear ratios were very slightly different, but were still rated the same.

Packard Merlins fitted to Lancasters required a slightly different control system, due to the injection carburettor. Even so, some Lancasters were fitted with Merlins from different factories, including Packard.


I HAVE heard that U.S. engines have much better parts interchangeability. Heard that for 20 years, and then someone in here said Rolls Royce fixed that issue rapidly and, by the end of the war, their parts were also interchangeable. I have never been able to confirm that in action because the active warbirds I know about usually have Packard-built Merlins in various states of parts mixes, usually with transport heads, sometimes new-production pistons and rings, and sometimes modern ignition systems. Basically, they are hybrids.

Since the transport heads were British designed and built, doesn't that point to interchageability?

Prior to Packard starting production the British had already productionised the Merlin, with Ford UK being involved in that process.
 
What was different about these, Wuzak?

I am not sure what was different about them. They were based on the 100-series engines, so would have kept any improvements there.

Other than that, I can only assume that changes were made to improve reliability and longevity.
 

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