Discussion in 'Found Boats For Sale' started by CaptainHinckley, Sep 14, 2018 at 10:07 AM.
That would be a fun project. Not many repower options thou with that shaft size.
These are decent boats often overlooked. Very thick solid glass hulls. A buddy of ours has an all molded top sedan cruiser that rolls more than new designs but has a comfortable motion imho and offers a lot of boat for affordable price.
The shaft in the Bruno trawlers are 1 3/8” diameter I believe.
These boats push very easily. Someone on here could chime in on how much power 1 1/2” can take or running currently.
We looked at a Webber’s 34 molded lobster top with Yanmar 300 that cruised at 18 and toped at 25.
Always nice in a head sea and in a following sea as well. But she likes to roll beam-to a sea. But, all boats are a compromise.
Hey diesel Jerry,
What is a maximum horse you can “safely” put on a 1-3/8” shaft? Assuming the engine is geared correctly?
This ones pretty close to what my son has. He has a Volvo TAMD60C, 255hp. Not sure size of shaft. This one Also looks like it has a wooden keel piece. Ive been on the 34 in a moderate sea and it wasnt bad on the nose. They do have a bit more roll to them in a beam sea. Nice boats and ditto on the thicker solid hull. We replaced the ducer in his and I was impressed with the hull thickness.
How thick was her hull? Did you happen to take a photo of the inside of the drilled hole?
I didnt take a picture but I would estimate a little over an inch. This was on stbd side about 12" from keel. We were going to redrill ducer hole for a bigger one and I remember a 3/4" piece of stock wasnt close to the right thickness and two pieces stacked was too much. We wound up finding a new ducer to fit the hole. Its thick..
I will have to figure that out on the prop calculator on BD, then I apply a little of "Diesel Jerry" thinking. Let's say BD says I could put 250 hp to a 1 1/2 shaft. I wouldn't go higher than 200hp. You have to look long run. I try to build/repair/spec out for 20+ years of service.
Thanks for the help.
So an Aquamet 22 1.5 shaft could handle 320hp with a 2:1 ratio with a safety factor of 3(required by ABYC on recreational vessels). 360 hp for 1:77 ratio. That is provided that they used Aquamet 22. If they used a lesser grade of Stainless, or even bronze you would be looking at even lower HP.
Two things the Calculator on BD doesn't take into consideration are the weight of the boat and the size of the prop being turned. So if I were repowering this I wouldn't go higher than 250ish, and would want to remove and inspect the shaft. Also would want to know for sure what the shaft was made out of.