Pitch Conundrum.

Posted By: Ron Pierce 26s, Lafayette/Dillon CO
Date: 11/15/07 5:25p.m.

Report: outside forum guidelines

In Response To: prop pitch (pic) (Bob s-v Watermark - Mac26S - Ottawa River - ON)

In theory, if your engine were able to turn 5000 rpm, divided by the 2.33 gearing, it would turn the prop at 2146 PRM. 5 inch pitch would move water about 894 ft per minute with no slippage and perhaps 600 ft/min with one third slippage. Thats about 6.8 mph or 6 knots. They say the pitch is too low if the engine will over-rev. It's probably a safe bet at 5 pitch. You might be able to find another prop maker with different pitches available though, if you like the 6.5. 10 inch is probably better than 9- more traction so to speak. Good luck.