Merlins > Packard vs RR

[Sid327]

(I hope it's okay to reactivate an old thread)

The Packard Merlin: How Detroit Mass-Produced Britain's Hand-Built Powerhouse - Tested.com

A quote, word for word from the book ''The Merlin In Perspective'' by Alec Harvey-Bailey (RR Heritage Trust)

"Packard built engines to very high standards of quality. Technical problems were not dissimilar from those experienced on British engines and when comparing like with like modification standards there was nothing to choose between engine sources.
At squadron level there were times when there were fortuitous variations in reliability either way but when dealing with large numbers at Group or Command level there was good consistency in results between British and Packard engines.
The 60,000 engines produced by Packard for the RAF and USAAF were of inestimable value.''..

As an added note: The RM17SM was fully cleared and type-tested @ 2,200hp but was never used. These modifications were included in the V1650-9
RM17SM additional info from this book:
Max Type Tested HP (3000rpm +30lbs boost) = 2,200hp
Max Flight Clearance Tested Power = 2,340hp
Max Endurance Tested Power (3000rpm +36lbs boost Water Injection) = 2,640hp
Longest High Power Development Test. 100hours @ 3000rpm +18lbs boost) Two successful tests.
Source: The Merlin In Perspective, Page 84.

 

[fastmongrel]

(I hope it's okay to reactivate an old thread)

The Packard Merlin: How Detroit Mass-Produced Britain's Hand-Built Powerhouse - Tested.com

A quote, word for word from the book ''The Merlin In Perspective'' by Alec Harvey-Bailey (RR Heritage Trust)



As an added note: The RM17SM was fully cleared and type-tested @ 2,200hp but was never used. These modifications were included in the V1650-9
RM17SM additional info from this book:
Max Type Tested HP (3000rpm +30lbs boost) = 2,200hp
Max Flight Clearance Tested Power = 2,340hp
Max Endurance Tested Power (3000rpm +36lbs boost Water Injection) = 2,640hp
Longest High Power Development Test. 100hours @ 3000rpm +18lbs boost) Two successful tests.
Source: The Merlin In Perspective, Page 84.

Merlin's were not hand produced in any factory in Britain. At RRs Derby factory the engines were assembled by teams of workers who built an engine from the crankshaft up but they were built from production line produced parts. The reason for this Derby produced all the special and prototype engines two engines built side by side could be different marks of engine.

RRs factory at Crewe produced thousands of engines on production lines.

Ford's factory in Manchester produced thousands of engines on production lines.

The government factory in Glasgow produced thousands of engines on production lines.

Britain produced almost 100,000 Merlin's the USA produced almost 60,000 V1650s and Merlin's none of them apart from a few hundred prewar engines were hand made.

 

[Reluctant Poster]

Merlin's were not hand produced in any factory in Britain. At RRs Derby factory the engines were assembled by teams of workers who built an engine from the crankshaft up but they were built from production line produced parts. The reason for this Derby produced all the special and prototype engines two engines built side by side could be different marks of engine.

RRs factory at Crewe produced thousands of engines on production lines.

Ford's factory in Manchester produced thousands of engines on production lines.

The government factory in Glasgow produced thousands of engines on production lines.

Britain produced almost 100,000 Merlin's the USA produced almost 60,000 V1650s and Merlin's none of them apart from a few hundred prewar engines were hand made.

At the end of 1941 Packard had produced a grand total of 45 Merlin's while Rolls Royce had produced approximately 23,000 mostly in Derby and Crewe. This is more than that marvel of mass production the Liberty. At that point only the Hispano V8 exceeded that number. Rolls Royce went from producing maybe a 1000 kestrels in a good year to over 18,000 Merlins a year in a 5 year period. It must have been an incredible apprentice program to train enough craftsmen to do that.
Here's a couple of videos on Merlin production:


Here's one on Wright production

Here's how Chevrolet made car engines in the 30s

 

[pbehn]

The heat treating is the key, Flyboy, as in a forging a part, it is anealed (heated) to relive stress in the part. Engine blocks (automotive) are often not heat treated in manufacturing and left to cure naturaly. I learned about it studying manufacturing, in the 60s when Ford came out with its high performance 427/428 engines they would pick the earliest castings they could because the natural heating/cooling relived enough stress to allow the extream machining required (all FE blocks started as 331cid castings), and still not break in use.

This may/may not have anything to do with the Packard Merlin but is more of an "I wonder" on my part.

wmaxt

A long time since this was posted but this is barrack room metallurgy. Annealing as a process depends on the metal being heat treated and the results you require. The metal is heated above the re crystalisation temperature and allowed to cool, the temperature it is heated to, the time it is held there and rate of cooling depend on the metal itself, the shape and size of the object and the result required. Solution annealing of stainless steel is almost identical to quenching of carbon steel just at a higher temperature, annealing of carbon steel is rare because it usually involves heating to 900C plus then allowing to cool in the furnace itself. Normalising and stress relieving of steel is usually done using still air as a coolant and sometimes at lower temperatures.

 

[wuzak]

As an added note: The RM17SM was fully cleared and type-tested @ 2,200hp but was never used. These modifications were included in the V1650-9
RM17SM additional info from this book:
Max Type Tested HP (3000rpm +30lbs boost) = 2,200hp
Max Flight Clearance Tested Power = 2,340hp
Max Endurance Tested Power (3000rpm +36lbs boost Water Injection) = 2,640hp
Longest High Power Development Test. 100hours @ 3000rpm +18lbs boost) Two successful tests.
Source: The Merlin In Perspective, Page 84.

The V-1650-9 was a 100-series Merlin, not the RM.17SM. So similar to the Merlin 130/131 in the Hornet.

The RM.17SM had a larger supercharger - 12.7/10.7 vs 12.0/10.1 inch in the normal 2 stage engines.

 

[Sid327]

The V-1650-9 was a 100-series Merlin, not the RM.17SM. So similar to the Merlin 130/131 in the Hornet.
The RM.17SM had a larger supercharger - 12.7/10.7 vs 12.0/10.1 inch in the normal 2 stage engines.

But without the Corliss throttle body? (I can't find much about this type of TB in the book mentioned, though I notice the Griffon 57/58's had this type of throttle body too).

Talking about TB's have you seen the throttle body the Soviets invented during WW2 which apparently was worth 100hp?

 

[tomo pauk]

...
Talking about TB's have you seen the throttle body the Soviets invented during WW2 which apparently was worth 100hp?

Polikovskiy's device?
Calum (member here) made one via 3D printing.
In real world, it worked best well under the rated height, though.

 

[Sid327]

Yes, that's it))
I saw this video about it a while back:-


Have you any info in regards to the Corliss (not sure if the spelling is correct, maybe two "l's").
The Brits had it on the Merlin 130/131 (I saw an actual engine with this type of TB at the FAAM Museum a long while ago) and I see the same type on the Griffon 57/58's too.

 

[Reluctant Poster]

Yes, that's it))
I saw this video about it a while back:-


Have you any info in regards to the Corliss (not sure if the spelling is correct, maybe two "l's").
The Brits had it on the Merlin 130/131 (I saw an actual engine with this type of TB at the FAAM Museum a long while ago) and I see the same type on the Griffon 57/58's too.

The

Yes, that's it))
I saw this video about it a while back:-


Have you any info in regards to the Corliss (not sure if the spelling is correct, maybe two "l's").
The Brits had it on the Merlin 130/131 (I saw an actual engine with this type of TB at the FAAM Museum a long while ago) and I see the same type on the Griffon 57/58's too.

The Corliss is very old device actually invented for steam engines. When it is fully open the passage is completely unobstructed unlike the butterfly valves typically used in aircraft engines. Modern high performance engines often use slide valves for the same reason. Rolls Royce also liked the Corliss as it had less friction making it easier to operate in remote installations like the Hornet.

Corliss Valves

 

[fastmongrel]

The Corliss throttle valve was recently re-invented for 4 stroke Moto Cross engines. It was hailed as a brilliant new invention till someone pointed out it was patented in the mid 19thC and is probably a lot older

 

[fastmongrel]

Half throttle

 

[Sid327]

Thank you for the info
''Reluctant Poster'' & ''fastmongrel''


I had seen the steam engine info after searching but was looking more specifically for a piston engine diagram or drawing.

Since having a gander at the Merlin 130 in the Navy Fleet Air Arm Museum (Yeovilton, U.K.) it interested and intrigued me.
Yes, understand about the slide throttles, SU carbs were a great example if a little slow responding to blipping the throttle (though using a much thinner oil helped).

Here are some decent pictures of the throttle housing on a Sea Griffon.

*pics found on the internet.*

Edit: fastmongrel, re your photo, what is this TB fitted to? I can see it's a Japanese make.

 

[Reluctant Poster]

Thank you for the info
''Reluctant Poster'' & ''fastmongrel''


I had seen the steam engine info after searching but was looking more specifically for a piston engine diagram or drawing.

Since having a gander at the Merlin 130 in the Navy Fleet Air Arm Museum (Yeovilton, U.K.) it interested and intrigued me.
Yes, understand about the slide throttles, SU carbs were a great example if a little slow responding to blipping the throttle (though using a much thinner oil helped).

Here are some decent pictures of the throttle housing on a Sea Griffon.

*pics found on the internet.*

Edit: fastmongrel, re your photo, what is this TB fitted to? I can see it's a Japanese make.

One of my many Rolls Royce books has a cutaway I'm sure. When I return to the US I'll find it

 

[fastmongrel]

Don't know what engine it is
https://motocrossactionmag.com/amp/inside-secrets-of-the-innovative-rd-genius-throttle-body/

 

[pbehn]

Hello PBehn,

Do you believe that this influenced the idea of the Rolls Royce Merlin requiring parts to be chosen and fit to a particular engine without a great concern for parts interchangeability? This is not intended as an argument but REALLY is a question. Redrawing for proper tolerances for parts interchange obviously took a fair amount of time for Packard and I wonder if that was an unnecessary cost for a short production run.
Many prototypes need to be modified in some way for actual mass production.

Did Rolls Royce change their methods to adjust to an obvious need for mass production when the time came?

- Ivan.

Here is an old thread with the issue discussed at length. There seems to be a school of thought that Packard had a factory that mass produced Merlins while Rolls Royce made a few engines in a garden shed. Most Merlins were actually made in UK.

 

[fastmongrel]

Most Merlins were actually made in UK.

Going on RR Trust figures 112,545 Merlin engines built in the UK
Going on wiki figures 55,523 Merlin and V1650 engines built by Packard and 6 by Continental

 

[buffnut453]

Going on RR Trust figures 112,545 Merlin engines built in the UK

Imagine the number of parts bins they must have had to hand-pick each component to ensure it matched the weights of the other similar components. Oh...and the number of precision scales involved to do that work. Those RR chappies were sheer geniuses. They must have invented a TARDIS to fit all of those people, machines and storage bins into their factories.

I'll get my coat!

 

[Ivan1GFP]

Here is an old thread with the issue discussed at length. There seems to be a school of thought that Packard had a factory that mass produced Merlins while Rolls Royce made a few engines in a garden shed. Most Merlins were actually made in UK.

Hello PBehn,

I followed this thread for a while much much earlier.
You answered a question that I wasn't asking. It wasn't about quantity of production and where the production was.
Ford in UK also produced quite a few Merlins though I don't recall the number, but again, that was not really the question.
It was more about the design of the engine that required a team to fit the pieces as I understand was the process used by Rolls Royce (and one which required skilled labor) as opposed to much less skilled labor required in a production line arrangement more typical of automobiles and whether that was a conscious choice for an expectation of very limited production.

When it became obvious that production numbers would be much higher, did tolerances change to guarantee parts interchangeability which apparently was not a feature of the earlier engines?

- Ivan.

 

[pbehn]

Hello PBehn,

I followed this thread for a while much much earlier.
You answered a question that I wasn't asking. It wasn't about quantity of production and where the production was.
Ford in UK also produced quite a few Merlins though I don't recall the number, but again, that was not really the question.
It was more about the design of the engine that required a team to fit the pieces as I understand was the process used by Rolls Royce (and one which required skilled labor) as opposed to much less skilled labor required in a production line arrangement more typical of automobiles and whether that was a conscious choice for an expectation of very limited production.

When it became obvious that production numbers would be much higher, did tolerances change to guarantee parts interchangeability which apparently was not a feature of the earlier engines?

- Ivan.

I pointed you in the direction of this thread, it contains exactly all the numbers produced by each factory, that is why I pointed you here. You are now wilfully ignoring information (you said you read it) because it doesn't suit your Uncle Sam flag waving exercise. This nonsense appears every once in a while and is debunked, it has been debunked on this thread, do not ask me to go over it all again and debunk it again. You obviously believe what you want to believe regardless of any facts, so go to bed believing that Rolls Royce built their engines on a kitchen table until Packard arrived in 1942 to win the Battles of Britain and Malta. I am done here on this topic.

 

[Ivan1GFP]

I pointed you in the direction of this thread, it contains exactly all the numbers produced by each factory, that is why I pointed you here. You are now wilfully ignoring information (you said you read it) because it doesn't suit your Uncle Sam flag waving exercise. This nonsense appears every once in a while and is debunked, it has been debunked on this thread, do not ask me to go over it all again and debunk it again. You obviously believe what you want to believe regardless of any facts, so go to bed believing that Rolls Royce built their engines on a kitchen table until Packard arrived in 1942 to win the Battles of Britain and Malta. I am done here on this topic.

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?