Reply With Quote12-15 3 blade menkins is where I would start. That boat prolly has a steep strut angle if you didn't change it.
I am trying to figure out what prop to put on my '22 Schiada. It is a '74 so a heavy layup old cruiser with a 502/502 in it and a T-400. The boat has a 1-inch shaft and is a 10-degree V-drive. Where do I start. I am trying to figure out what gears are in it and have come up with the #'s 500.5. Does this mean anything to anyone? As far as I can tell the boat has always been a family skier and has a C-500 Casale V-drive in it. Any guidance would be appreciated. The boat has a 10-7/8 X15 prop on it right now and it is cavitating coming up on plane.
RR
12-15 3 blade menkins is where I would start. That boat prolly has a steep strut angle if you didn't change it.
12-15 3 blade menkins is where I would start. That boat prolly has a steep strut angle if you didn't change it. call Dallas
First of all a C-500 is a 12* v-drive. You need to know the angle of the strut and the gears in the v-drive. A crude but effective way to figure the gears: put a mark on both input and output flanges straight up. Turn input one full revolution and see where output ends up, measure with angle finder, divide 360 by angle on angle finder equals percent of overdrive. Sample, 36* plus equals 10% over. I have a C-500 with 22% over gears collecting dust. Strut angle is important as well as estimated horsepower of engine in picking the right prop. Hope this helps, once these basics are determined I'm sure some Schiada owners with similar specs can help out as Schiadas seem to be a little "wetter" than similar 21's or 22's.
HEY ROCKER; all above info is all true and you are at the bottom of the curve trying to dial your machine in. cavatation plate adjustment goes hand in hand with propeller ,add in horsepower to complicate the process. If you can stick the nose of the boat down at say 3500 r.p.m. you have a pretty good handle on your cav plate setting if you can't then maybe you should start there before prop
Huffpower has given you very good advice in my opinion.
Horsepower, gear ration & prop shaft angle are going to need to be determined before you will be able to get any prop manufacturer to give you a fair starting place. Dallas at Menkens built mine for our 21' River Cruiser but it's a twin turbo motor with a TH400 trans with 40% gears. He nailed it first time as far as I'm concerned since it outran our naturally aspirated flats first run out. Now we are building better/faster flats so that won't ever happen again!
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