What prop should i use

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I have just built a Aeromarine Stingray with mod zenoah 23 and i just cant seem to find the best prop to use.Just wondering if any one knows what would be suitable.Thanks Dave

[engineman351]

Dave, The best prop will be the one that works best for YOUR set-up..not any of ours. A good start would be an Octura X470/2. I have found on my Gas Deep Vees with a 23 or 231, a 470 with a little extra pitch or cup is a good all around prop. If the engine is a strong mod, a modified 1475 (cupped and back cut) works well too. The Prop Shop or VooDoo 7016's are good on a Vee too. If you really want to 'cut to the chase' so to speak, contact PropWorks' Bob Austin or Chris Hoffman (aka 'Dasboata') on e-bay. You might pay these guys a few bucks for a prepped prop, but in the long run you will have fewer non-performing props in your box. If you do prep your own, a sharpened and balanced prop is a must... makes a big difference.

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Thanks for your reply, do you prefer to use a 2 or 3 blade prop to get the best performance out of your boat because i have always used 3 blade.When i first started racing i was told the best was a 3 blade so i stuck with that.What is the main difference between them.Thanks.

[engineman351]

Dave, I have found that a three blade of the same diameter and pitch loads the engine more. I think as you increase torque (like from a 26cc) you can get a three blade to work as well or better. Also with a 3 blade you could try reducing the diameter. Remember that on a Vee you are limited on how high you can raise the strut (vs a Cat) to get a prop unloaded, so overall I think a two blade is a better choice. Also, I can balance a two blade easier than a three blade. That said, I have a friend that was running a 45" AM Cyclone Cat with a Hanson mid-mod G23PUM. We tried a X670, X470/3 and a P767/3 and the smaller P767 three blade gave him 3 mph more. The 70MM props delivered exactly the same speed. The smaller dia prop let the motor rev more and it delivered more mph. To really know what a prop change is doing you need to test and have some 'tools' for the job. The simplest tools are a measured length and a stop watch. Then there are tachometers, GPS, radar guns, and now data loggers. I like the SenDec tach and GPS, because they are around $75, and you don't need another person or a lot more bucks for a laptop or 'dashboard'. You didn't mention how you drive is set up, but I would assume it's surface drive. The props I mentioned ealier should get it going pretty well. RC

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Thanks for that and yes i'am running a surface drive.At the moment i am running with a 7016/3 so i might try a x470/2 as you said earlier.Thanks for your time.Dave