Sorry to ask but what does it means BHP when talking about engines?

Is it best horse power or something like that.

Brake horsepower. Used to be measured by attaching a fluid filled drum to the crank, now measured using an electronic gizmo. Googling for "brake horsepower" should throw you up lots of useful info.

I guess the higher the number the more powerful the engine, right?

Hi Jucava,

Yes. Power from an engine is measured with an open throttle (that is, maximum throttle setting) and the engine is slowed down with a brake to measure the force it produces at different speeds.

Power is a multiple of the torque (turning force) and the speed it produces this torque.

Imagine pushing a weight up a hill. The force you apply to the ground is equivalent to the torque, but in a straight line, and the speed you manage to push it up hill is equivalent to the revs per minute of the engine.

-David C.

Yes, the higher the number the more powerful it is. But don't be misled by the figures you read in magazines

On an engine the propellor is the brake that loads it to a certain rev. Put a smaller prop on and it loads it less so it can rev higher. Generally speaking, higher revs give more BHP but to get to the revs most engines develop their maximum BHP at you need to use a prop that's so small it's useless for flying the average model. The moral of all this is don't buy an engine simply based on how much HP the manufacturers say it makes.

downunder is right, dont be misled by BHP, if you notice that 2 strokes have more BHP than 4 strokes of roughly the same size. However due to the fact that a 4 stroke can sling a bigger prop (and other factors we wont get into) it will out pull a twostroke as far as vertical performace goes.