Originally Posted by IBWET
they obviously know how important it is,why use 2.5ltrs to get 150 bhp in an outboard when you can get the same figure from 1.0 in a bike engine
Reliability is one reason; if you run a high performance bike engine at WOT for a large part of its life you'd probably find it was a fairly short life, same for performance cars. Race engines often have a life expectancy of just a few hours, as an extreme example of that, and at the opposite end of the scale the engine in my Dad's Cessna was about 5.5 litres (5.something anyway) and produced 160hp - all for extreme reliability. And in 25 years the fan only stopped once so it must work
I agree with you though - I'm surprised they don't quote torque figures, it must be about the only engine industry anywhere which doesn't! A torquey engine would surely not "bog down" when you put a few lardy divers in the blunt end so it must be a selling point you would think.
It occurred to me recently when looking at Suzukis - the DF140 is only a whisker over 2 litres while the DF150 is 2.8something, I bet there is a big difference in the torque (and therefore power) outputs at say 2500rpm.
I suppose the bottom line is that more torque means bigger engine means more expensive, so it may be a better marketing ploy to get a buzzy engine producing lots of HP because it's cheaper to make and therefore a more competitive product if power is the number that goes up in big flashing lights?