What was used to measure engine size before litres (or CCs) and when did metrication happen?

Question

Presumably cubix inches - so when did metrication happen in the USA and UK?

Thanks guys. I'm interested that the Americans chose to (or were forced to) convert to metric from imperial on this thing alone.

Answer 1

Metric was used in Europe from before cars, so European manufacturers have always used litres or ccs.
The British originally used a form of horsepower - but it was calculated rather than measured, so was not a reliable indicator of the output of the engine. However it was used for taxation, and gave rise to model names such as the Austin 7 and Standard 10. France used something similar (and still does for taxation) hence the Citroën 2cv. Litres (and cc) became common from the late 50s (e.g Morris Minor 1000).

American manufacturers used cubic inches until the late 70s or early 80s.

Answer 2

Cubic inches, whuich was derived from the formula:

C.I.D. = B x B x S x .7854 x no.of cylinders where "B" is the cylinder bore in inches and "S" is the stroke (the distance the piston travels) in inches. As an example, a so-called square engine of 4" bore and stroke would be figured out as 402.1248 sq. in. which would probably be rounded off as a 400 square inch displacement engine. 1 liter is equal to 61.02 cubic inches, so that same 400 inch engine would now be called 6.5 liters.

This change was brought upon in 1970, by American manufacturers who switched to metric usage to conform with European manufactures, in part because most European nations base their auto registration fees upon engine displacement in liters.

Answer 3

Cubic Inches.

Metric measurements became the norm in the early '80's

Answer 4

the yanks have always gone by imperial sizes such as cubic inch ,where British or European built cars have always been measured in metric,the yanks like to be different

Answer 5

Horse power. Its not right about cc becoming the measurement only in the 1980s. I had a 1000cc ariel square four motorbike in the 1950s.

Answer 6

It's always been metric, ever since the IC engine was invented.

In Europe.

Answer 7

I really don't know about the engine size but when I started driving 65 years ago cars were rated in HP, (horse power).