I am re-propping this year and have some questions. My current props are 4RH21 and 4LH21, 3-blade props on a 42ft., Trojan Sea Voyager, 1968, weighting in at 35,000 lbs. Engines are 68', 427 Ford Interceptors at 300 hp.
With that, can someone tell me what the "4" and "21" in the numbers 4RH21 and 4LH21 mean, how I can identify the pitch and know if the current props have been cupped. I am currently looking at the Michigan Wheel 4-blade, 21" brass props for replacement. Is it true that I can get better fuel efficiency and smoother cruises with the 4-blade over the 3's?
With that, can someone tell me what the "4" and "21" in the numbers 4RH21 and 4LH21 mean, how I can identify the pitch and know if the current props have been cupped. I am currently looking at the Michigan Wheel 4-blade, 21" brass props for replacement. Is it true that I can get better fuel efficiency and smoother cruises with the 4-blade over the 3's?