I thought that I had seen one of the guys doing builds now choosing an Ultra Prop 4 blade but couldn't find it. I'm going to order the 4 blade setup and give it a try. If it don't work out the way I want I can use the blades on my 3 blade hub and have a spare.

Im going to try this because I like the longevity of the carbon blades but the Ultra Prop blades are narrow and don't seem to have the push I get from the wider wood props. My solution to this is going with more blades for more surface area. I've not seen anyone trying the four or five blade on a 084 so I'm going to give it a whirl. The ultra prop is also a little quieter than my stick prop.

Hi Papee, I have a general question about the multi-blade props...In this case lets use your 3 and 4 blade ultra props...Theoretically... How will going from a 3 blade{with a higher pitch} to a 4 blade{with a lower pitch} shift the RPM powerband ?? Where's the trade-off between the two ??? {One would have more thrust at a lower RPM}...Or would the 4 blade offer more thrust throughout the working range ???

Adding a blade would lower the pitch because of the torque necessary to spin the prop. I'm looking for more surface area and more push. Multiple blades are supposed to be more effecient at moving air. The more blades should have more thrust in all rpm scenarios if set up correctly providing the motor has the torque to spin it.

I think it was salt texan that was going with either the 5 or 6 blade ultra. As u know im in the works with building a reduction drive and I was throwing around that same idea with multiple blades but im not sure. I'll be looking for the results. Oh ima send you a pm in a sec. Itll be worth your while to take a look ;)

Steve

I am using the ultra 5 blade on a generac 40 hp
Ron

Thats right lol ok yeah I knew it was someone from texas lol. Hows your build going Ron?

I knew someone was but I was thinking it was on a 084. Guess I'll have to try it, you just don't know until you try it. I do like the ultra prop but the narrow blades just don't have the cruise performance compared to the wider blade/chord of my stick prop. Adding more blades will help with that hopefully. This is just something I wanted to try before changing the motor position to put on a reduction drive.

I haven't had any time to work on the redrive because I'm still working on body panels for the 65 GTO we are restoring.

I got side tracked with bow season want start it till after the first of the year.
I do have redrive,prop,alum sheets and motor sitting here.
Ron

Ok hope your at least out there sticking something. Ill be awaiting the results with the multiple blades like that.

back to the original post..For what its worth papee my buddy had a three blade sensenich prop on his big boat and then he traded it for I think a 6 blade warp drive. Same diameter and he said the multiple blades gave him more push and top end. So who knows. Experiment and see how it works. Im still throwing around using multiple blades vs a 2 blade when I go with my reduction drive. A buddy that works at water walker said I should look more at getting the tip speed up as opposed to multiple blades but idk. Kinda conflicting results between the two. I think it really boils down to what ive read you say a long time ago about every boat is different and will perform differently.

I'm not sure what he meant by getting the tip speed up. Running direct drive we are turning these props at their high end recommended speed already. I do know that most props have that sweet spot that is lower than the max rpm where the perform the best.

I know from running the ultra prop that you can run them at around 2800 rpm and if you push them to a higher rpm they do not gain any thrust even though they are rated at a max rpm of 3100 rpm. It's better to just jump up another degree and drop the rpms to the 2800.

With the ultra prop three blade on my engine each degree changed the rpm about 250 rpms. This would be different on each motor even though they are the same motor depending on the condition of the motor, how it's tuned, and the modifications done to the motor. The size and design of the hull would also come into play for this figure.

Im thinking about the 67 or 65" whirlwind and I was asking him about what the diference is with a multiple bladed prop with less diameter such as the ultra prop with 5 blades at 60". I think he was getting at the certain mach speed that it should be turned at. Idk it was all greek to me lol. I would think that the more blades the better as well. When I get the drive made up I may just buy a set of hubs because I have enough blades with the two probs. Time will tell.

so far I have had pretty good luck, 3 turkeys ,a doe and a big 10 point.
Backstrap gravy and hot biscuits is hard to beat.
Ron

Very nice. Send some of that this way so I can make some deer jerky.