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why do we measure engine size in metric units and not imperial. Every other measurements we use regularly are in imperial and always been, but not engine size. Why not and who was the first to us metric for cc?
Edited by Pugugly on 15/09/2008 at 00:18
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I've wondered about this myself -- engines were measured in litres/cc long before we joined the E.U.
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I think you'll find steam engines were measured in imperial units, and Americans still use cubic inches. Perhaps someone with a historical memory (let's face it, there's enough of them here ;>))will enlighten us.
On a side note, I was quite surprised to see the bores of car brake and clutch cylinders expressed in imperial round numbers quite recently.
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The related conundrum that puzzles and possibly even slightly offends my remaining conciousness, is the tyre size mystery of a combination of metric and imperial.
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I think you'll find steam engines were measured in imperial units and Americans still use cubic inches.
Certainly that's true of steam railway engines. Being an owner of Harleys and an old Yank truck, I can also confirm that whilst Americans still do use cubic inches to refer to their own vehicles, foreign cars tend to be quoted in the metric idiom.
Given that there are differences between certain American imperial measures and British ones (gallons for example) perhaps we should for once be reluctantly grateful to our Continental friends for imposing their heinous system on us, at least it's the same everywhere!
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>Given that there are differences between certain American imperial measures and British ones..
When I came back to the UK from Texas I decided to bring my Chevy with me.
I got endless questions from friends about what modifications I would need to make to get the car legal for use in Ingerlaand.
The answer that drew blank stares for a few seconds was when I told them I would need to get the speedo recalibrated from MPH to Furlongs per Fortnight.
Kevin...
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As a complete guess maybe it's the origins of motoring in Europe being with Rudolph Diesel and Carl Benz, plus the common use of French and German engines in early cars. These would all have been built in metric units. I believe a number of British engines were actually designed in imperial units, but bore and stroke were converted to metric when quoted in literature.
However the old fiscal UK 'horsepower' used in the early 20th century for taxation purposes used imperial measurements in its calculation - Square of the bore diameter in inches divided by 2.5.
JS
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Slightly off-topic; a friend of mine who works as an aircraft maintenance engineer tells me that all his apprentices have to be taught Imperial measurement when they start in the industry, as again the Americans still work in it and they, of course, dominate the industry.
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"However the old fiscal UK 'horsepower' used in the early 20th century for taxation purposes used imperial measurements in its calculation"
Strangely, Spain still uses this method - the power is quoted in KW, but a measure called "caballos fiscales" (fiscal horses?) is used for annual car tax purposes, approximately a tenth of the equivalent BHP - for example, a Golf 2.0TDI is 103 CV (approx 130 BHP), but is taxed based on 13.19 "caballos fiscales"
Edited by colinh on 15/09/2008 at 00:23
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"delibrate" mistake in the OP - thanks for the e-mails prompting the correction. Month's worth of free postings to anyone that spots it before midnight !
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"to use metric for cc"
... rather than ...
"to use metric for capacity"
Eh PU?
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all his apprentices have to be taught Imperial measurement when they start in the industry
I had to pick it up as I went along, and I'm 35! There was a great emphasis when I was at school in the 70's and 80's on only teaching metric units, as that's all you'll be using...
I'm not hard of thinking, but I still can't remember if it's 14 or 16 ounces in a pound. Fortunately I can mentally convert km, litres and mm into old money pretty quickly :-)
Edited by Webmaster on 21/09/2008 at 13:34
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There was a great emphasis when I was at school in the 70's and 80's on only teaching metric units as that's all you'll be using ...
How sad that the teaching profession could predict so badly what life would be like after the 1980s.
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I learned imperial at school and still can't tell how far a kilometre is or guess the weight of something in kilos. But no problem guessing how far I've travelled in miles, or the weight in ounces of a bag of sweets.
And there's no way I'm going to the pub to ask for half a litre of Guinness!
Edited by grumpyscot on 15/09/2008 at 07:33
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The UK was metric during roman times we then changed to a mish masm of imperial and now semi returned to metric far easier to work with,but the one metric measurement that baffles me is the German "zoll " it is in fact an inch something that all tyre diameters are measured in no matter what the land.
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In Germany, non-metric weights were, and probably still are, in customary use. The pfund for example, the zentner (100 pfunds or about 50 kilos) or hundredweight (1/20th of a ton). In France, the livre (weight). Demi-livre and quart de livre are used also, I believe. Just thought you'd like to know that its not just the UK that has parallel systems of measurement:)
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I'm not hard of thinking but I still can't remember if it's 14 or 16 ounces in a pound.
I think of the bathroom scales with '7' inbetween each number of stones - that's 2x7 pounds in a stone, and there's a different number of ounces in a pound, so it must be 16. Easy :-)
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I think of the bathroom scales with '7' inbetween each number of stones - that's 2x7 pounds in a stone and there's a different number of ounces in a pound so it must be 16. Easy :-)
LOL, that's the funniest explanation I've heard in ages. Thanks for that.
I've often heard it said that the imperial measures are easier to understand because you can deal in halves, quarters etc etc. So why is it that everything is not base-16 then?
I'd be happy to support such a system as it would be mathematically elegant. Say -- 16 inches in a foot, four feet in a yard, 1024 yards in a mile etc.
How exactly is base-12, 14, 16, 20, 3, and so on "easy"?
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I believe the Chinese invented the arithmetical system of tenths, hundredths, thousandths etc.
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In many fields the use of cubic centimetres was replaced by mililitres years ago.
Good job the car industry did not: "An inline 4-cylinder engine with a capacity of 1800ml" . Sounds like part of a recipe.
(But then if it had changed over we would be used to it so it would not sound so silly).
Edited by Rich 9-3 on 15/09/2008 at 11:39
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"How sad that the teaching profession could predict so badly what life would be like after the 1980s."
Indeed -- the intransigence of the British public knows no boundaries ;)
"I learned imperial at school and still can't tell how far a kilometre is or guess the weight of something in kilos."
Nah -- you've just never taken the time to learn the system properly. My generation (in their thirties) have had to learn two systems just to accommodate you lot.
"In Germany, non-metric weights were, and probably still are, in customary use. The pfund for example, the zentner (100 pfunds or about 50 kilos) or hundredweight (1/20th of a ton). In France, the livre (weight). Demi-livre and quart de livre are used also, I believe. Just thought you'd like to know that its not just the UK that has parallel systems of measurement:)"
The german pfund, French livre etc are defined as 500g. So hardly a parallel system. Would you rather have a situation in a global economy where there are 200 different definitions of what a 'pound' is? If the UK had just been sensible and redefined the pound, pint etc etc in terms of scalar divisors of metric units like everyone else, the problem would have gone away years ago.
The irony is that the so-called imperial units in use today are not the ones the older generations grew up with anyway -- they were redefined slightly so that they are measured in terms of their metric equivalents. So the inch is exactly 25.4mm -- it's just a translation factor. In this case, if the powers that be had had any sense, they'd have redefined it as 25mm instead, wiping out a whole load of trouble. Etc etc.
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My generation (in their thirties) have had to learn two systems just to accommodate you lot.
I have a nagging feeling that we were taught imperial and metric at junior school (I'm 36); but when we started secondary school, imperial was dropped? Or am I imagining the 'being taught both' bit?
In France the livre (weight). Demi-livre and quart de livre are used also I believe.
>>
On an Air Mauritius flight (Airbus) a few weeks ago, the display screen showing altitude was alternating between metres and feet in English; but then doing the same in French, alternating between metres and pied .
I blindly assumed France was fully metric, they dont still use pied do they? So it could be peculiar to Mauritius with their dual language issues?
(In Mauritius, French is the dominant language over English despite English being stated as the "official language").
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If i may add another question to the debate. Why are engines NEVER the actual size we know them as (eg my rover 2497cc, not 2.5ltr)? Is there some reason why manufactures can't be accurate on this?
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It's so the thing can be rebored and not go out of class.
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Re-bore?
Now there's an old-fashioned traditionalist ;>)
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What's the problem if they are not measured in imperial units? Metric engine size measurement is just universal.
Rest of the world has learnt English and they spell better than what some schools here teach.
Metric is a better system and that's it. It is one EU thing which I find good :)
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Question of engine size. It's all very well giving the capacity of a seven-litre unit in cubic inches, because 400 or more sounds OK. But an 850cc car would sound a bit pathetic being called a 52-cubic-inch unit.
Stand by for the US to drop cubic inches to preserve the tattered remnants of redneck V8 macho in these days of little 3-cylinder turbodiesels.
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