Difference in going from 2 bladed to 3 bladed prop?

[tremors]

I have a 30inch tunnel hull with a K&B 3.5/gold carb. I've been using a 2 bladed Octura X440 prop and the boat really hauls. I recently received a X440 3 bladed prop by accident (shipping foul-up) and decided to keep it to try it out. What if any performance changes can I expect? I would just go and try it but I haven't had time to get to the lake and I have been real curious.

Thanks, Geno

 

[ggillman]

Well to me the 3 blade prop's bite harder, but do not rev out as high as the two blade.

A lot of the guy's runnin .21 Seaducer mono's run the 3 blade X440.

I have not tried a 3 blade on a tunnel, check it out and see how it does, I would be interested in what ya find out.

Gene ;D

 

[tremors]

I'll be running the tunnel this weekend. I'll take some notes on the differences between the props.

I'm posting some pics of it below. I never did figure out what kind/brand of hull it is. Make by the pics one of you guys know????

View attachment 69

 

[tremors]

Its a wood hull. Just about 31 inches long. I bought the hull built and already finished. I just installed all the mechanics.

View attachment 70

 

[tremors]

Last pic

View attachment 71

 

[Brian]

I tried the X440/3 on my K&B powered 3.5 hot shot sprint last year.It really pulls hard coming out of the turns,a little slower on the straights just dont slow down. I think its a little too much prop for a stock K&B, but give it a try and let us know.

 

[chunk t]

I inherited a x437/3 a while back that I'm now in the process of getting ready to run. I've made some mods to it (similar to what i've done to my 2-bladers) just to see what happens in comparison. I'll let you know once I get to run it.

chunk

 

[ggillman]

Nice hull by the way, as far as what it is, Sheeeeesh!

I am guessin here so, It reminds me of the older Dumas Hotshot IV

but the nose is shorter and the backcut colwing is different,

Also reminds me of the early Prather Lapcats, but they were glass, Whatever it is, Nice job on the buildup

Gene ;D

 

[Brian]

Geno, I was looking through some old plans and found your boat. Its a Dumas,Hot Shot 21 Kit#1313,no longer in production.My grandfather had this boat years ago.It came with a all wood center section and the hull and deck were fiberglass.Someone has modified the nose of yours to a point , the original had a blunt tounge shape. Brian

 

[Brian]

Geno if you would like this paper(not really plans but a assembly instruction sheet) I can mail it to you. Brian

 

[GTR]

Hi Guy's

The tunnel might be a modified early hotshot but looks suspiciously like one of the Steve Muck tunnels (lightning I think they were called). I'm pretty sure he did these as both glass and all wood kits.

GT 8)

 

[tremors]

Wow, thanks for all the info guys. I bought the hull finsihed and never run from a guy for $50 bucks that was unloading some of his R/C stuff. I didn't think to ask him any info on it other than if it floats, LOL.

As for the tips being modified, they were. Twice by me after some minor shore contact. As of this past weekend the tips are now black. My friend bought a used MRP Miss Bud and while running itI got cought looking at it while my tunnel speared the shore.

As for the X440 3 bladed prop. I didn't like it. It seemed to go a bit slower, skip a bit on the straight aways and drop the transom lower into the water on the turns. Even after trying different angles and hieghts on the outboard.

I'm back to the X440 2 blade and she runs great. I also tried a Prather 215 2 blade prop without noticing any differences compared to the X440 2 blade.

Laterz, Geno

 

[TimD]

The 3 blade prop seems to work better on Mono's.

The 2 blade props generally work better on tunnels from my experience.

Tim.