I read online that Every 17cc = approx. 1-HP

[RoofTopPigeon]

I read online that Every 17cc = approx. 1-HP
Does this sound accurate?
Since My new mower is 163cc
Dividing that by 17cc would make it a 9.5 HP Mower!

 

[ILENGINE]

Dealers are told to divide by 29

 

[7394]

Dealers are told to divide by 29

I believe that puts my 21.5hp Kawasaki at 25.03 (that seem right ?)

726cc divided by 29 = 25.03

 

[ILENGINE]

It is not an exact science. It is relatively close though. Is your 21.5 hp engine net or gross. Is that based at 3600 rpm or 3100 rpm. Differences in carb, timing, valve lift, and duration can all effect the hp in the same displacement.

good example was the Kohler command 18,20,22 hp engines. The difference between the 18 and 20 was a screw in the side of the carb that preventing the throttle butterfly from opening more than halfway. The difference between the 20 and 22 was it added spark advance. All three engines used the same short block.

 

[Rivets]

I always use cc's, devided by 17, devided by 2, should give you an approximate HP. As IL said, it's not an exact science.

 

[7394]

ILENGINE- I would say it is at 3600 rpm, not sure if that is gross or net tho. It's got plenty of power to spare. I know torque peaks at about 3200 rpm.

Interesting. My Kawasaki FR651V comes in various higher HP ratings, using same long block. I figured it was just a matter of how they 'tune' put in it.

Rivets- That formula works well too.. Thank You both.