Homefront
10-22-2009, 04:32 PM
Gee, my first post!
I have a 16' fiberglass skiff with a 40" flat bottom. Sharpie type planing hull (like a miniature Pacific City Dory), low freeboard, approximately 200lbs hull weight. The old (70's) 25 Chrysler it came with is in poor shape (needs at least a carb rebuild and a bearing in the lower unit), and makes the hull sit low in the water at the stern.
I happen to have a 6hp horizontal Briggs engine, which gave me the thought of mounting a motor amidships, building a shaft log, and running a 3/4" drive shaft to a prop. I'd also build a rudder to steer with. This weight placement would get the stern up quite a bit, and probably help in other ways.
I'm aware that I'd have to deal with the exhaust in some way or suffer the fumes/noise consequences and I have a few ideas to develop. I'd use a pulleys/belt setup to get the power from the motor to the shaft and build a pivoting motor mount that would use the motor's weight to keep tension on the belt. This would also allow me to rig some kind of mechanism to tip the motor up enough to relieve the belt tension, effectively putting the boat in neutral. I realize there are no hard and fast answers, but my main questions are the following:
1) Might 6hp get the boat on plane with 2 people aboard? I don't have to fly; 12-15mph would do.
2) What kind/diameter/pitch prop would I use? I realize that it would involve some trial and error.
I also found a new Honda 13hp for a good price ($500+); the same questions apply.
I'd like to keep the whole installation under a thou, which seems doable with either motor.
All suggestions welcome :p .
I have a 16' fiberglass skiff with a 40" flat bottom. Sharpie type planing hull (like a miniature Pacific City Dory), low freeboard, approximately 200lbs hull weight. The old (70's) 25 Chrysler it came with is in poor shape (needs at least a carb rebuild and a bearing in the lower unit), and makes the hull sit low in the water at the stern.
I happen to have a 6hp horizontal Briggs engine, which gave me the thought of mounting a motor amidships, building a shaft log, and running a 3/4" drive shaft to a prop. I'd also build a rudder to steer with. This weight placement would get the stern up quite a bit, and probably help in other ways.
I'm aware that I'd have to deal with the exhaust in some way or suffer the fumes/noise consequences and I have a few ideas to develop. I'd use a pulleys/belt setup to get the power from the motor to the shaft and build a pivoting motor mount that would use the motor's weight to keep tension on the belt. This would also allow me to rig some kind of mechanism to tip the motor up enough to relieve the belt tension, effectively putting the boat in neutral. I realize there are no hard and fast answers, but my main questions are the following:
1) Might 6hp get the boat on plane with 2 people aboard? I don't have to fly; 12-15mph would do.
2) What kind/diameter/pitch prop would I use? I realize that it would involve some trial and error.
I also found a new Honda 13hp for a good price ($500+); the same questions apply.
I'd like to keep the whole installation under a thou, which seems doable with either motor.
All suggestions welcome :p .