View Full Version : Over-hub Big Ear Prop on Bass Cat

08-03-2018, 01:30 PM
Does anyone have an idea what a chopper style prop would do on a heavier hull like a 20 foot Bass Cat, 225 PXS? Advantages, disadvantages? Hull is approx. 1750 pounds. Specifically an Eagle 4.

08-03-2018, 02:28 PM
Ya never really know how until ya try. I have a Triton Tr-20 and the fastest prop to date is a 27 SRX ran 1 1/2 inches above pad. Totally against the grain of what’s supposed to work. I also ran a chopper and it didn’t run that great with poor hole shot. Cut it to an ET style with added camfer on leading edge and ran much better. I think the high rake of the SRX is the key. I think if it’s gonna work you will need a nosecose with low water pick up to allow you to run it high and with very little to no positive trim. I think that cuts down on enough drag, allows boat to run flatter instead of nose up, and prop being on/ above surface allows for added stern lift. This setup makes my boat drive like a dream and allowed me to get in the mid 80’s. Only drawback is not worth a darn in rough water because boat runs so flat and on pad so quick it’s hard to hold nose up to prevent from piercing big waves

08-03-2018, 02:33 PM

You really need a nose cone/lwp to reap the benefits of a chopper style prop. You have to get it high enough to surface it! hole shot will also suffer if it's buried!

08-03-2018, 04:53 PM
I have a low water pickup on my torquemaster. However, I can only run as high as 2.75” below pad. With my Fury, which has a lot of stern lift, I run out of water pressure when it gets up and really starts compressing air. Do the 3 blades have less stern lift, more bow lift?

08-03-2018, 06:26 PM
I felt my fury three blade had more bow lift. It ran with the nose really high. In general the big round ears have more bow lift, the pointer the tips get the more stern. Three blades normally faster but the fours carry the load better, so can be faster on heavier rigs. The bass cat could react differently than the triton. The triton is concave just ahead of the pad before it flattenes out at pad then goes slightly convex at the very end of the pad. The concave part funnnels air under the pad, thus the reason it liked to run flat. In general a boat is more aerodynamic running flat, but the tricky part is finding a prop that’ll pack the load of these tubs we fooling with and get the rear up high enough out the water without sticking the noise in the air to reduce hydrodynamic drag. I never dreamed the little ole blades of the SRX would pack the load like it does, I wanna try a pro et style 4 blade next. I think the trick was getting the lower out the water, with mostly just skeg in the water. I feel the bottom of the extended gear case from the nose cone sitting above the water level actually helps pack the weight, acting sorta like a mini pad if you will. The paddling effect of the blades reentering the water also giving you extra lift upwards in the rear. I would think adding the extra blade of a four blade would improve stern lift even more. Also when you get the motor that high, it’s fastest with the motor at neutral trim preventing you from loosing thrust from having to go into positive trim wasting energy from the upward thrust instead of straight out the back.

It’s a lot simpler to stick with an over the hub prop like the fury. Because you gonna have to add a nose cone and block off your upper water intakes to really make most over hub props run right. And if the over hub don’t work out, the nose cone will more than likely slow you down sub merged. If ya can borrow someone’s over hub prop, run it where your motor is and see how it acts, if its within a mile an hour or so with your fury, then more than likely it’ll fly when you get it on the surface. If it’s a turd don’t waste your time. The bass cat is a little heavier than mine, so I think a big diameter 4 blade like the eagle 4 would be your best bet

08-04-2018, 09:38 PM
That is good info, thank you for the time.