Engine size for Wooden Boat?

[rolmops]

There is another thing that is important. You mentioned that the height of your transom is 60cm which is give or take 24 inches, Outboards come roughly in 3 sizes length wise . usually called short, long and extra long. Short is 15 inches long 20 and extra long 25. Many manufactures make them 18 ,23 or 28 long. You will have to either take an Evinrude longshaft (23inch) an extra long 25 inch or adjust the height of your transom to whatever length of outboard you decide upon

 

[Texasmark]

yes, the IMO has formula to determine max hp. CFR 33.183 mirrors the IMO rules.

since the boat is a tiller and not a console steer, and is not a flat bottom boat the formula in your case would be (Transom Width x Length at water line x 0.8 ) - 25

estimating your transom at 4 ft. your length at water line at 13.6 ft your maximum hp would be 18.5

for all other capacity calculations, look up the boat builders handbook.

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Glad you posted pictures. Forget what I said. That boat is too narrow to load it up with HP.