I recently purchased a 1965 Allied Seabreeze sailboat which is outfitted with a 25hp Atomic 4.I am looking to re-power the boat and Im considering the BD1005 with PRM 80 Gearbox and Atomic mounts.My question is does the existing engine bed need to be reinforced/strengthened to accommodate the increased weight/torque of the new diesel?Ive included a picture of the existing mount.
I also have a question regarding prop pitch.Particulars for the boat are:LOA = 34.5ft, LWL = 24ft, Displacement = 13,400lbs.The propeller cove is 15 x 8 and is currently fitted with a 13 diameter prop (do not know the pitch).Due to the angle of the shaft in the cove, it looks like 13 diameter is about as large as the boat will accommodate.What would be an appropriate pitch for the new engine?
The condition of your engine beds will govern if you need to make any repairs or strengthening. The BD1005 weighs 331lbs. The A4 with the reduction ratio weighs 330 lbs and the 1:1 version weight 310 lbs so the weight of the engine is not a concern. I have found that Allied's construction to be excellent and have found very few problems.
I have run a prop calc for you and a 13"x10" three blade RH propeller will suit you just fine. I have worked on a 50% blade area ratio (Michigan Wheel DJ355 is a great propeller). I hope that this helps,
Thank you for the reply (and additional info you provided during our phonecon last week).I will let you know I asked members of the Allied Seabreeze Owners Association about re-powering with a Beta, and the members gave the engine, the company, and you two thumbs up!With that said, I would like to just reaffirm a few things before I place the order.Since I hope to only experience an engine swap on this boat once, is there any value to going to a larger Beta 35 engine?I know I'm limited in prop diameter, so is there any value in extended engine service life (running at hull speed at a lower rpm), additional power for strong currents/head seas, other?that would make this a consideration? Or is the Beta 28 with the specified prop the "perfect match"?
I know we discussed this by telephone, but for the benefit of others that may refer to this forum I will reply to your question.
There is no benefit to using a larger engine due to your propeller restriction. Basically, you will not be able to transfer the additional power to the water.
