3 or 4 blade? round or semi-cleaver?

**chevyrulz** · 04-23-2018, 02:47 PM

boat is an 1860 alumacraft with an F115, i ran a 3 blade round ear aluminum 16 pitch (see pic) & it hit 45mph, barely trimmed it & was headed toward the rev limiter, i think it will turn a 21 no problem & am going to test a 19 and a 20, both are stainless 3 blade round ear. it does have a jack plate, & the cav plate is 1.5" above bottom of hull currently, jack plate all the way down....anyone know whether this hull will prefer a certain blade type & care to explain why?

anyone run a similar setup & know what prop i should go with?

i'm curious to learn more about blade shape & how it affects performance.

**XstreamVking** · 04-23-2018, 02:52 PM

That transducer is in a terrible place...You will get a lot of air on a flatbottom boat. Go 4 blade....

**chevyrulz** · 04-23-2018, 03:21 PM

yea i figured 4 blade, and yea i need to move that transducer over to the right more, not as bad as it looks in that pic, but it isn't ideal, it's just inside the edge of the blades, i ovbiously weren't thinking when i mounted it lol

what about blade shape? round ear? or semicleaver? or?....looking at the powertech website options & damn there's a lot of blade shapes...i would think with this much power pushing an 800lb hull, i should be able to run a semicleaver 4 blade 2-3" up on the cav plate, no?

& how bout pitch on the 4 blade...19 4 blade should turn like a 21 3 blade, right?

i should have MPH & RPM numbers on the 3 blade round ear props in 16, 19, & 20 pitch in a couple days

**XstreamVking** · 04-23-2018, 03:26 PM

Square blade stern lift, round ear bow lift. Gen speaking anyway. Does it porpoise at all now when trimmed up?

**chevyrulz** · 04-23-2018, 03:27 PM

thank you, i barely trimmed it before hitting the rev limiter, the hull has a ton of hook in it so it tends to dig the bow, but once i put the trim to it, i get plenty of bow lift, i have an 18gal fuel tank under the rear bench