The Secret Horsepower Race by Calum Douglas (and piston engine discussion)

Hi Pasoleati,

Pasoleati said:
The device my cousin's father had/has is like a desktop computer. Very easy to use.
Click to expand...

You're still considering capability only.

Ergonomy is relaxed reading sitting in my comfy chair, or wherever I want, just as I do it with all of the other books I read, few of which feature such an unergonomical combination of book format, font size, and font legibility as the quote font in the "Horsepower Race".

Regards,

Henning (HoHun)
 
HoHun said:
Hi Pasoleati,



You're still considering capability only.

Ergonomy is relaxed reading sitting in my comfy chair, or wherever I want, just as I do it with all of the other books I read, few of which feature such an unergonomical combination of book format, font size, and font legibility as the quote font in the "Horsepower Race".

Regards,

Henning (HoHun)
Click to expand...
The problem of the quote font has nothing to with size. Just compare it to a Jane's AWA and test them side-by-side. JAWA has a very small font, yet it is most readable.
 
As someone who tends to read before sleep more than any other time, taking a desktop computer there would be difficult at best. If you like small fonts and overly busy pages, go for it. Other options should be available and for many of us, are preferable.
 
Hi Pasoleati,

Pasoleati said:
The problem of the quote font has nothing to with size. Just compare it to a Jane's AWA and test them side-by-side. JAWA has a very small font, yet it is most readable.
Click to expand...

In my world, the size of a borderline illegible font has a lot to do with its legibility. I don't know which world you're living in as it seems to have little similarity to mine.

Regards,

Henning (HoHun)
 
HoHun said:
Hi Pasoleati,



In my world, the size of a borderline illegible font has a lot to do with its legibility. I don't know which world you're living in as it seems to have little similarity to mine.

Regards,

Henning (HoHun)
Click to expand...
Even if the quote font was doubled in size, it would still be far from ideal in legibility.
 
 
Foo Fighter said:
As someone who tends to read before sleep more than any other time, taking a desktop computer there would be difficult at best.
Click to expand...
I recommend an e-reader. Comes with built-in lighting, scalable fonts, lightweight.
Furthermore, I recommend to move the discussion of readability of books to a dedicated topic.
 
Pasoleati said:
And you will pay for my extra costs caused by it? In full? For every single book?
Click to expand...
For myself, I enjoy reading, which means I need to be able to enjoyu reading. With this in mind, why BUY something I cannot enjoy?

I purchased a book series (Sci-fi) a while ago, the whole series.

When I got it every book was close spaced and in 6 point type. Rather than faff I sent the whole lot back. If you cannot enjoy reading you can always watch a dvd or whatever. Films are topics are usually abridged too so less time to get bored.
 
Arjen said:
I recommend an e-reader. Comes with built-in lighting, scalable fonts, lightweight.
Furthermore, I recommend to move the discussion of readability of books to a dedicated topic.
Click to expand...
No thanks, bloody hopeless. The topic is the presentation of books in a thread about a book so is relevent. Thanks.
 
HoHun said:
Ergonomy is relaxed reading sitting in my comfy chair, or wherever I want, just as I do it with all of the other books I read, few of which feature such an unergonomical combination of book format, font size, and font legibility as the quote font in the "Horsepower Race".
Click to expand...
Had a legally-blind veteran in one of my college classes, he'd lost most of his sight in an IED blast.

He had a magnification device that was about the size of a paperback book that sat on top of the book he was reading. This was ~15 years ago, I'm sure modern versions are about the thickness of a Kindle.
 
My lecture on Beatrice Shilling and the R.AE.E. pressure carburettor, is online >

View: https://www.youtube.com/watch?v=zktw8uUc2hU


It concentrates on why the R.A.E. carburettor was ignored, if it had not been, the famous "orifice" would never have been
needed.

I find it dissapointing she was awarded OBE for the restrictor, and not the R.A.E. carburettor, which was only needed because
her earlier work was ignored ! Personally I think she probably felt a bit irked by that.

1711102754136.png
 
Very interesting and well researched.

Just two remarks, I believe, the direct injection saved a lot of fuel not only by better metering, but also by avoiding fuel losses during the valve overlap, I think you also mentioned this yourself somewhere else, but not here by the end of the video.

Despite all disadvantages, the carburetor in front of the supercharger saves some compressor work by evaporative cooling during the compression. Many hotrodders could use a roots charger aft of the carburetor without charge air cooling and without a dramatic increase in knocking (with moderate pressure ratios).

When all the fuel is evaporated during the compression in the supercharger, the outflow is ideally a homogenous gas mixture which wouldn’t unmix on its way to the cylinders (only true without charge air cooling). However, I know that a compressor doesn’t really homogenize the air/fuel mixture perfectly so this is just a bit too optimistic idea. If I remember it right, that was also described by Harry Ricardo.

A bit off topic, but I think I remember, some American radials had a refined system where they sprayed fuel axially into a hollow compressor shaft from which the fuel was guided to the surfaces of the radial compressor and formed a kind of cooling film on the compressor wheel.

For those intrested in aircraft carburators:

View: https://www.youtube.com/watch?v=J8a3ur6Ar_k&ab_channel=PeriscopeFilm


They aren't really simple devices and you rarly find any information on how a carb works at low loads. The working principe is totally different and has nothing to do with the venturi. In this video you can also find a lot of things which will not work with negative g loads....
 
Last edited:
sienar said:
Have you ever come across a photo or drawing of the XR-7755s crank?
View attachment 726798
Click to expand...
I guess the main bearings looked like that:

Zylinderrollenlager mit winkeleinstellbarem Außenring | NSK

Zylinderrollenlager für Loslager in Strangguß- und Papiermaschinen. Der winkeleinstellbare Außenring gleicht Winkelfehler aus und minimiert das Auftreten von Kantenpressung, die vollrolligen Wälzlager bieten eine hohe Tragfähigkeit.
www.nskeurope.de www.nskeurope.de

Unlike in the bearings showen above, the spherical ring was very likely directly floating in the axial split housing. Due to the splitting, the shperical ring could be monted and was trapped in the housing and could move out ("eliminates the need of locking devices").
 
At the same time a very interesting book, well-researched with an obviously deep technical knowledge of a vast array of issues (design, development, fuels, lubricants, etc.), and one of the worst, being so badly structured and written. In fact it is more a linear chronicle. The author should have teamed with a real historian, as it seems to be the case for the next one.
 
BROF said:
At the same time a very interesting book, well-researched with an obviously deep technical knowledge of a vast array of issues (design, development, fuels, lubricants, etc.), and one of the worst, being so badly structured and written. In fact it is more a linear chronicle. The author should have teamed with a real historian, as it seems to be the case for the next one.
Click to expand...
Badly written? Are you serious? Calum's writing is extremely good!
 
BROF said:
At the same time a very interesting book, well-researched with an obviously deep technical knowledge of a vast array of issues (design, development, fuels, lubricants, etc.), and one of the worst, being so badly structured and written. In fact it is more a linear chronicle. The author should have teamed with a real historian, as it seems to be the case for the next one.
Click to expand...

1714391559427.png

Wait ... I`m not done...


1714391605105.png
 
BROF said:
At the same time a very interesting book, well-researched with an obviously deep technical knowledge of a vast array of issues (design, development, fuels, lubricants, etc.), and one of the worst, being so badly structured and written. In fact it is more a linear chronicle. The author should have teamed with a real historian, as it seems to be the case for the next one.
Click to expand...
That whooshing sound you heard was the entire point of the book going over your head.

It is EXACTLY a linear chronicle and written as such.
 
Let's take a trip into alternative history, if we may. You are given the time, the money and the resources to fix the Rolls-Royce Vulture. What do you say after careful consideration of the problem?

A. "Yes! It's worth doing! This engine offers advantages that no other aero engine currently built in metal can match, and these are..."

B. "Forget it! The Merlin is showing itself to be beautifully amenable to improvement, the Sabre is proving more amenable to having its bugs fixed and the Griffon and Centaurus will give us all the high-horsepower grunt we need until that freakish Whittle thing is ready to take over."

C. "This engine is so intrinsically flawed it deserves to spend eternity in the same corner of Hell as the Blackburn Botha, and the designers need to be drowned in a large vat of tapioca pudding."
 
Calum Douglas said:
Its fine, I tell people never to buy my books all the time. They never listen, but what can you do.

View attachment 727338
Click to expand...
You can keep doing what you are please, those who care will understand the issues around the subjects and be very happy with the result.
Your book has centre stage on my bookshelves and it will be re read over etc. Possibly because of the times I was a kid at but either way, valued for the demonstration of the labour that went into it.
Rather looking forward to what comes next tbh.
Stay well, Sir, you and yours.
I am again, tbh, sick as a parrot and not getting any care from our glorious health system (Apart from being laughed at) so am in constant pain. Your book, and this place are two of those things that keep me going because otherwise, I would NOT be here.
Seeing as I am being open. You folks, are bloody brilliant and I thank the planet I live on for you all.
We have proud Russians here. Good, be proud of the good things Russians have achieved and will in the future, we are all better for those things.
Peace out.
 
pathology_doc said:
Let's take a trip into alternative history, if we may. You are given the time, the money and the resources to fix the Rolls-Royce Vulture. What do you say after careful consideration of the problem?

A. "Yes! It's worth doing! This engine offers advantages that no other aero engine currently built in metal can match, and these are..."

B. "Forget it! The Merlin is showing itself to be beautifully amenable to improvement, the Sabre is proving more amenable to having its bugs fixed and the Griffon and Centaurus will give us all the high-horsepower grunt we need until that freakish Whittle thing is ready to take over."

C. "This engine is so intrinsically flawed it deserves to spend eternity in the same corner of Hell as the Blackburn Botha, and the designers need to be drowned in a large vat of tapioca pudding."
Click to expand...
I dont have enough detailed technical info on the Vulture to be absolutely certain, but - broadly speaking, if you concentrate on ONE thing, you can make nearly any engine of fundamentally sensible type work.

But, it may well take you an entirely unacceptable period to do so. Work you put into an engine can be broadly categorised as either
A "making it not break"
or
B "making it better - more powerful - better supercharger etc"

You want something where working on the engine is mostly B, with a few short instances of A so the strength of the mechanical bits stay
ahead of the requirements on them.

If it needs almost all "A", you`ll get an engine which works, but might be useless as by the time you`ve got it working you`ll find everyone else started with something simpler and put all their time into "B" meaning their engines actually perform better although they might appear fundamentally less clever in layout.

I suspect the Vulture was 90% A and 10% of B

Once the Merlin got past the ramp head silliness, it was probably 20% A and 80% B.

You can always argue that "with just another year the Vulture etc would have got past its "ramp head silliness" zone" too, but
there is no good evidence that this was ever really about to actually happen. Hives and other RR people are always saying in letters that the Vulture was great but was never installed properly.

Another way of looking at it might be that if all your best people cant even get it working such that any deviations from perfect in terms of installation make it fall to bits, maybe, its just fundamentally not really up to it. (in fact there appear to have been rather more serious problems than the installation if you read letters NOT from RR)
 
Calum Douglas said:
but - broadly speaking,
Click to expand...
An excellent summation of general principles and the broader picture, thanks. So I'm beginning to think that the poor old Vulture lies somewhere between my options B and C.

Mind you, even a good engine can get taken beyond reasonable limits. IIRC the Griffon 101 with the two-stage, three-speed supercharger that got the Spiteful F.16 up to 494mph had a distressing habit of sh***ing the bed on regular occasions. I guess the harder you push it, the more of A you get while B gets a sharp dose of diminishing returns. That's when you know you've gone too far...
 
I have received the book early this year and still only got up to chapter 5 (1940 page 128) but I have thoroughly enjoyed the prewar engine stuff so far. It's by far one of the richest books about the technical history of military hardware I have seen to date.

The previous chapter delved a bit into French liquid-cooled engine research. Calum, I wonder if you had anything to say about the Gnome-Rhône radial engines as well? From my understanding both new generations of the liquid cooled (HS 12Z) and radial engines (GR 14R) implemented major structural changes but didn't completely adress reliability issues in 1940 testing or postwar use, so do you think these engines were a sound base for hypothetical 1941-42 fighting or would they still remain too outdated in some ways?

I do not know how much historical material you had available on French engines up to 1940 when you wrote the book or made videos about the subject, so maybe there is not enough to conclude either way. Recently I had found a few docs about the 12Z/12Y series on Safran's public database and in the Swiss archives, but I do not have the knowledge to make much use of what little information they have about the actual construction and materials of these engines.
 
Elan Vital said:
I have received the book early this year and still only got up to chapter 5 (1940 page 128) but I have thoroughly enjoyed the prewar engine stuff so far. It's by far one of the richest books about the technical history of military hardware I have seen to date.

The previous chapter delved a bit into French liquid-cooled engine research. Calum, I wonder if you had anything to say about the Gnome-Rhône radial engines as well? From my understanding both new generations of the liquid cooled (HS 12Z) and radial engines (GR 14R) implemented major structural changes but didn't completely adress reliability issues in 1940 testing or postwar use, so do you think these engines were a sound base for hypothetical 1941-42 fighting or would they still remain too outdated in some ways?

I do not know how much historical material you had available on French engines up to 1940 when you wrote the book or made videos about the subject, so maybe there is not enough to conclude either way. Recently I had found a few docs about the 12Z/12Y series on Safran's public database and in the Swiss archives, but I do not have the knowledge to make much use of what little information they have about the actual construction and materials of these engines.
Click to expand...
My two cents :
-in The great book of fighters (Green-Swanborough, 2001, MBI Publishing), it's said that the (12Y31 derivatives) Saurer YS-2 engine (1250 hp) of the Doflug D-3802 and the YS-3 engine (1430 hp) of the Doflug D-3803 prototype had reliability issues.
-Conversely, if there is no shortage of examples of problems for the HS 12 Z (89 or 17) equipping the French prototypes and the Hispano Aviacion HA-1109J/1112 K fighter series, I have, however, never read that they had problems on the aircraft series Ikarus-S49 C (HS 12 Z 17).
These two subjects have puzzled me for at least two decades...
 
Perhaps this is one of the origins of the hand built myth?
flying march 1947 hand built merlin.png
from Flying magazine March 1947
 
sienar said:
Perhaps this is one of the origins of the hand built myth?
View attachment 729819
from Flying magazine March 1947
Click to expand...
Eh, pretty close.

All British engines were hand assembled by a person called a "Fitter". The Fitter would take parts as they came off the line and would measure, mix and match until they got a set of parts that all fit together with tight clearances. No torque specs, the Fitter tightened the bolts "enough." The Brits had not heard of a Torque Wrench in 1940!

You see, the various parts as they came off the British lines had very wide tolerances that were "acceptable". So wide that it was possible to have a piston larger in diameter than the bore of a given sleeve.

But that Fitter would go through a stack of parts until he found a bore sleeve that a given piston would fit in, or would chuck the piston in a lathe to turn down to a size that would fit. That took a lot of time to assemble one engine.

What Ford did (they were making the engines under contract in the UK) was greatly tighten up the tolerances on the "as made" parts, so that every piston would fit in every bore sleeve (etc). This meant that the clearances between the parts were wider than the RR hand fitted engines, but you never had to search for the right size parts or take them to a lathe/mill to be modified to fit.

And it was the Ford UK plans that got sent to Packard.

Example: the RR hand fitted engines kept about a 0.020" gap between crank and bearings, piston and bore, etc. The Packard assembly line engines kept more like a 0.040" gap between all their parts. So the RR engines made a little more power and could be pushed a little harder, but the Packard engines could just be thrown together and they'd work first time every time.
 
Nicknick said:
Intresting, but I believe 0.002 and 0.004 is more realistic...
Click to expand...
At least in the case of crankshaft-to-bearing clearances, 0.040" is more accurate. Need space for a good oil thickness to support the crank.
 
0.04" is about 1 mm, usually the diameter difference (cold) in crank shaft bearings is around 0.05 mm! For a large aero engine bearing it will be a bit more, but since heat expansion further incease the bearing play when warm, you try to keep it on the narrow side.
 

Similar threads

Please donate to support the forum.

Back
Top Bottom