loose comparison regarding electric motor size and nitro motors

[1945dave]

I have a large stable of wonderful Nitro boats that I would like to convert over to fast electric. I understand I could fit the largest motor and battery sets that the physical space would allow and probably exceed any of the performance numbers the nitro motors of old provided, Not my main objective. Is there a resource or could someone just give me an approximation of electric motor sizes that are generally thought a good switch for A (.21), C (.40), D ).60) and F (.90) nitro motors?

Thanks

Dave

[carlcisneros]

what are the actual boats and motors in the boats that you have.
would be much easier to make a starting recommendation for ya.

[puttekula]

Isnt it a good start to compare the stated effect for comparison?

[ozzie-crawl]

possibly the easiest way would be comparing power outputs.

If a .40 is stated as 1hp then a 735 watt motor should be a equivalent.
But its hard to compare apples to oranges. most nitro hp quotes are BS. plus either side of there optimum rpm there not so good.
brushless motor has a much more linear power delivery.

[jcald2000]

If you want to run with the Nitros, not blast pass them we need to know what hulls, Monos, riggers, sport hydros in what motor class .21 .45 .67 .90 ect.

[carlcisneros]

[1945dave]

Ozzie yoiur responce so far makes the most sence to me. On the other hand you are also correct that the HP numbers for Nitro motors are all over the place with nothing that I can hang my hat on. I have dupicates of several of my boats with different motor prop combinations. For example I have two identical 55 inch deepvee hulls and while the OPS 90 is super powerful from a brute force HP perspective it can not turn the rpm's of several less powerful motors that have given me faster mph results using smaller props turning perhaps 5,000 rpm's more. so I undestand the intrique in doing this with fast electrics. Thanks for your input.

[1945dave]

for those asking exactly what nitro models I want to convert to give me their advice.

My first interest is a 45 inch carbon fiber Seaducer rated for .90 nitro or 26cc gas. 70 mph is reality. i think a 5692 Leopard is calling me but what KV?

for a hydro choice I have many choices available. Every engine size available for my Crapshooter outrigger fleet. I also have three wonderful vee hulls. One a previous world record holder Sightler setup by the late Doug Floyd. This is a 55 inch that could also handle what ever we can stuff into it.

So my thought process involves getting several ESC,S and several good motors of some various power capabilities. I was just hoping to get an idea where to start.

I will use the existing drive hardware and setup. Only need to fabricate a motor mount for each case, and some protection for the batteries. Man I would like to talk to someone having done this for some of our older great memories.

thanks,

Dave

[JIM MARCUM]

1945dave, 1945 Jim here. As you know, I have every KV in Leopards 5692 series. Which one you choose depends on how many cells you're running. And that all depends on your target top speed. Pick the KV that will give you the RPM you want at whatever number of cells you are gonna run. There's a cool speed/prop calculatior here on OSE.

In my 44" Avenger Pro cat I'm going to run a 730KV on 10S2P, for 27,010 RPM, starting with a X670 prop. It's setup to run FE T Offshore class & will be my main squeeze - for sure the biggest squeeze - at the FE Nationals in June. It should be ready for testing next week, lots of prop variations to try out. Goal is to have a top speed of 65-70 while still pulling well thru the corners, and Not running to hot.

My backup plan is to try a 1090 KV for 40,330 RPM and smaller props, starting with an X668, but that's really more of a SAW setup. Probably would cavitate too much and/or wash out in the corners. Testing should confirm what works best.

Please keep us posted on how well your setup works.
JIM
AKA: 1945Jim

[carlcisneros]

DAVE
the main thing with the Shooters is where to put everything. The distance between the boom tubes needs to be long enough to mount the lipos up in that area.
then you will have to fabricate a cowl of sorts as the motors are mounted more towards the rear (front end of the existing radio box). You just have to play with things and figure out where everything will go.

The Sightler (that brings back fond memories), you should have no trouble sticking a big Leopard or TP Power motor in that thing to get it to move out.
The boat in my avatar is an Insane 45" mono which has seen all power types available and is currently running Twin outrunners in its present life.
That conversion went fine for me to do as there is so much room to work with.

I have a new in box Jaguar 2 rigger and am toying with making it FE power. I just need to get off mu butt and figure out what needs to go
where and such.

Carl