Honda Engine for 19' Bartender

Hi

I've been wondering about using a small honda engine (105hp) in a 19' bartender.
http://bartenderboats.com/19-foot-bartender.html
http://cgi.ebay.com/ebaymotors/88-9...068207768QQcategoryZ33615QQrdZ1QQcmdZViewItem

The boat plans say to use a 35-50 hp engine. I have read up on marinization of diesel engines. While gas engines are different I am still thinking that a 105 hp engine will be fine for this boats power plant. Having the high powered engine run at a constant mid range RPM (3k-4k) should allow this motor to work for a while correct? I have also chosen this engine due to the inexpensiabe and widley avaiable amount of replament parts.

Now this is where I am confused. Would it be possible to use an automatic tranny from a honda, or would I have to convert a marine tranny for use with this engine. Even more confiusing is whether or not I would be able to use a FWD tranny.

Any help is appreaciated.

-Alex

 

For starters, I'm not so sure the 105 would be fine. That's twice the maximum design power for the hull, and could make it unstable. It will also make speed control in the displacement mode very difficult. If you do intend to use this motor, you might be wise to de-tune it to about 2/3 of its normal maximum.
I take it you're talking about the 4-cylinder out of an old Civic or similar.
As for transmission. The car automatic would not be fun to convert to boat use. Essentially you need F-N-R and possibly a second forward (high/low gearing) to get both planing and trolling speeds. The car has at least 4 forward gears which will only get in the way in the boat. A Civic's FWD transmission has a built-in differential and, in the case of the automatic, a torque converter; neither of these are good to have in a boat. (The FWD differential would have to be fully locked up or else it would just spin the free shaft and not the prop; the torque converter is redundant since the water around the prop already provides a fluid drive.) Successful conversions of car transmissions to boat use are rare, and are usually based on rear-drive units.