Whip sport 40 propping

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BACKEMF

Well-Known Member
Joined
Feb 16, 2005
Messages
154
Hi guys,

I'm building a Whip sport 40. My question is what rpm do the (nitro I assume) engines run at unloaded and loaded?

What size props can you turn with a 40 size engine.

I ask not because I will run a 40 engine, rather it will be electric but, it's important for me to know what size props nitro guys run and what rpm as well so I can be turning approx. the right sized prop.

Would 27,000rpm loaded be enough? What size props?

I could ask in the electric forum but, maybe I can learn more by asking people that have run this hull much longer with nitro than my electric power.
 
I run a X450/2 blade that i modified. Ran MAC 45. Some guys run a X648/2 blade. Depends on what your boat likes.

Call Brian Blazer. It's his hull. Good guy to talk to about boats.

Mike Starrett has ran a whip and it was cooking. Maybe he'll chime in.
 
Hey Ray,

I would definitely ask in the FE Forum to avoid using your motor or ESC as a fuse.

What works with a nitro engine is completely different that what will run with FE power. Your enemy is heat and high load. I'm sure the FE guys can offer a much better place for you to start with props suited to the engine/ESC/ cells you plan to use. Too big a prop with a nitro engine, will generally simply cause a nitro engine not to run very long. Heavy - too much prop load for you causes wisps of expensive smoke CHEERS !!! Bob
 
I run a 2280/5 Lehner 1450per/v on 6s....About 20 volts at amp draw. about 150 to 160 amps. Thats probably about 28k- 30k under load. Small prop 45/55 abc. Can't keep it on the water. 60mph plus. Lot more in it but it blows off.

I do know another guy that ran it on a 2215 Neu about 1400kv per volt with a x450...70 plus and he could keep it on the water.

Remember High amp draw means Great batts and Great Controller. I run a Schulze 40/160... and My buddy ran a 240HV.

Good luck keep us updated.
 
Hey Howard it's Ray S. I thought Mike Pages was running his Whip 40 at the MI Cup witha 1250kv 1527 1Y and turning about a 55mm prop.

I was getting worried a 55mm prop would case too much prop walk. I'll start smaller anyway. Hopefully the custom motor being made for me by TP Power will be a bit high in the KV range like 1300 or so. I asked them to make me a 4070 1Y with approx. 1250+ Kv It will be done in a few weeks but, the hull is just started.

I may call Brian Blazer or Mike Pags and see exactly what he's got cooking in his.

It's nice to know what size prop the nitro guys run so as not to go to big on prop. we will see. I sold the Sirius 1580Kv motor hoping the 1250kv would be less amps.

Off to the electric section I guess...

Thanks Guys.
 
Hey Ray,

I would definitely ask in the FE Forum to avoid using your motor or ESC as a fuse.

What works with a nitro engine is completely different that what will run with FE power. Your enemy is heat and high load. I'm sure the FE guys can offer a much better place for you to start with props suited to the engine/ESC/ cells you plan to use. Too big a prop with a nitro engine, will generally simply cause a nitro engine not to run very long. Heavy - too much prop load for you causes wisps of expensive smoke CHEERS !!! Bob
When I find the approx. correct prop I'll give you a shout for some tweaking.
 
Ray,

I run an X646 three blade or an X450 three blade on my gen. 1 Whiplash with an CMB 45 HR.

Good luck on your project.

Bert Dygert
 
Last edited by a moderator:
Thanks Bert. This gives me the confidence that turning a big wheel is going to be o.k.

Back to work on it.
 
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