Greetings to the list. This is my first post and I just joined today.
I have a 34 foot Searunner Trimaran with a Farymann 12 hp single cylinder diesel. It is heavier than I would like, as weight on a multi is critical. I could save about 100 lbs with a Beta 20 or about 150 lbs with a 16. All up cruising design weight is 8000 lb, about 6,000 lbs for weekend sailing. I don't have the prop specs at the moment but there is an older Martec 2-blade folder that goes with the Farymann.
Any suggestions with this limited info would be appreciated.
Thanks,
Fair winds,
Rann Harrisburg, Oregon S/V ETAK in Long Beach area of Southern California
I will have to assume that you have a Farymann A30. In the past I have repowered a monohull (Cal2-29) with the Beta 14 (BZ482) after taking out an A30 and we were able to re-use the 3 blade fixed prop that was behind the A30. The new engine was able to spin the prop faster and thus boat performance under power was much improved. The noise and vibration also went away!
Unless your boat can almost plane under power, I think that the Beta 20 or 16 will be overkill and suggest the Beta 14.
A fixed prop will give much more drive than a folding prop but will have more drag under sail. I hope that this helps you.
You are correct in assuming the Farymann is an A30 engine. The design parameters for the Searunner 34 call for an engine weight of 300 lbs or less and horsepower to around 20. I have not motored the vessel with the Farymann as it was inoperative until I hauled the engine out. I had it rebuilt and have just put it back into the engine compartment but have not hooked it up yet. It would be easier to replace now rather than later I think, hence the questions I asked in the first post.
I note only a four kilo weight difference between the BZ482 and the 602. If I plan to use a high output (~100 amps) alternator and/or holding plate refrigeration, would the 16 be more appropriate?
Cost is always a factor as well, so I will need to call and discuss those differences with you.
The Beta 14 and Beta 16 are very close in size and thus in weight. Because of the actual layout of the engine it is easier (and therefore cheaper) to fit a large alternator to the Beta 14 and Beta 20 than it is to the Beta 16. We offer a 70 amp alternator on all of these engines and this should produce the output that you want for your refrigeration. The alternator can also be boosted with an Adverc controller or Balmar regulator.
The Beta 20 only weighs 234lbs complete with the standard transmission. Regards, Stanley
