Poll of the Day > Anyone Know How They Calculate...

(+) Yeah! (+)

wattage to cubic centimetres when trying to calculate vehicle insurance, or whats street-legal or not?

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not sure but looking it up I get something like 15 cc = 1 horsepower and 1 hp = 745.7 watts. so 1 cc ~= 50 watts

the cc to hp number varies a lot though. seen between 14 and 22 cc = 1 hp. that gives a range of something like between 34 and 53 watts per cc. I think the 745.7 number is pretty consistent though, so if you have hp you can convert more reliably.


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Hey thanks. I guess there can be a lot of variables since rotary engines dont really follow that formula. A stock 1300cc Wankel in the FC3S produces 145+ HP. 1300/15 = ~86.7 HP based on the numbers youve shown.

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this old site has a short explanation of how HP is determined

(wayback machine link)
https://web.archive.org/web/20050308211159/https://www.rustyiron.com/engines/rig/horsepower.html

DETERMINING THE HORSE POWER OF AN ENGINE.
Multiply the area of the cylinder by the length of stroke in inches and that product by the number of revolutions per minute then divide by the constant 10000 for two-cycle or 13400 for four-cycle engine, the result will be the I.H.P.

EXAMPLE
Four-cycle engine, 4" bore, 4" stroke, 1000 revolutions per minute, constant 13400.
Then: 4" bore equals 12.56 area, then 12.56 x 4 equals 50.24 x 1000 equals 50240 divided by 13400 equals 3 I.H.P. for one cylinder, then to find the combined H.P. for multi- cylinder engine, multiply by the number of cylinders.

probably not that useful

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also, I don't see any laws regarding engine power. most vehicle modification laws are about other things, like exhaust or noise.

https://www.calgary.ca/cps/Pages/Traffic/Vehicle-modifications.aspx

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Sahuagin posted...

also, I don't see any laws regarding engine power. most vehicle modification laws are about other things, like exhaust or noise.

https://www.calgary.ca/cps/Pages/Traffic/Vehicle-modifications.aspx

<50cc doesnt require a license but may be eligible to be driven on the road with other vehicles that require insurance if other requirements are met. Some countries use different-coloured license plates to signify smaller engines and therefore they pay less insurance etc. The question came up when talking about an electric longboard.

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zebatov posted...

The question came up when talking about an electric longboard.

seems to count as a "prohibited miniature vehicle"

http://www.transportation.alberta.ca/Content/docType41/Production/small_vehicle_booklet_final.pdf

Prohibited Operation: These vehicles are motor vehicles, as defined in the Traffic Safety Act; however, they also meet the definition of miniature vehicles which are not permitted on a highway in Alberta, including sidewalks alongside the roadway. While many of these motorized vehicles will be used in a pedestrian-like manner, the operators of these vehicles do not meet the legal definition of pedestrian

Permitted Operation: Miniature vehicles may not be operated on a highway in Alberta; they may only be operated on private property. The definition of highway on page 4 of this document includes privately owned places that the public is ordinarily entitled or permitted to use for the passage or parking of vehicles, for example shopping mall parking lots. In law, these vehicles meet the definition of a motor vehicle; however they do not fit the definitions of mobility aid, motorcycle, or pedestrian.

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