I put a 13 X 9 Gori 2 blade on my on my Yanmar YSB12 equipped 27 MKIII and after 7 or 8 years of service have no regrets whatsoever. The pitch of the prop you select for your 30 depends very much on your engine and gearing, but in general you want the largest diameter prop that will still give adequate clearance. Larger props are more efficient, all else being equal. My engine has approximately 2:1 gearing and the 9 inch pitch works well and does not load the engine too much. If you have an Atomic 4 with no reduction gear then a slightly larger prop diameter with less pitch will give you a better match to your engine than the prop you propose. A lot of A4s were equipped with 2 blade Michigan wheel 12 X 6 fixed props as original equipment, but whatever prop you select you should pick one that will present a similar load to the engine as the original equipment. If you make the diameter bigger, you should make the pitch less, unless you want to change the torque demands on the engine.
Steve Thomas C&C27 MKIII ---- Joe at Zialater via CnC-List <cnc-list@cnc-list.com> wrote: I received the blessing from the Admiral to equip Zia with a folding prop this season. I have been looking at our options and the Gori 2 blade geared prop 11.5 X 8 looks like it would do the job. Before I pull the trigger on this, I would like to check with the list for opinions/experiences on brands, model etc. Currently we have a 2 blade fixed. Thanks a million. Joe Zia 30 MK1 Annapolis _______________________________________________ Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go to the bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com
