Convert 72 inch gas to electric

[R2j2texas]

Using formulas found on line I figured I need a 8500w motor. The boat is a 72 inch mono hull. Not sure if I need to go to dual props or single. Then I found a TP5660 (56mm x 92mm) on OSE web page which say it produces 10K watts max. Should I start with a motor like this or something else. The boat is old and made out of fiberglass. It looks like it has a weed eater engine. Would maybe like to race in one day. There was a club her in San Antonio Texas before COVID but not sure if they are still here. Don't want to build this boat and break rules that will cost me money to correct. Will need help deciding other options. I have gone through the videos about calculating motor, and power but not sure what is the best options. I would appreciate any help you could provide.

[fweasel]

Racing classes have specific rules with regard to the batteries, motors, hull type, and hull length. If you want to race, you need to know the class you plan to compete in first. I don't race in sanctioned events and know nothing about that.

A 72" mono is a big hull and would do better with twin 56mm motors. You'll be running 10-12S per motor to keep your current demand down. You desired run time will determine how many batteries and their capacity. Hopefully someone with a similar build will chime in with first hand experience.

[tbonemcniel]

Using formulas found on line I figured I need a 8500w motor. The boat is a 72 inch mono hull. Not sure if I need to go to dual props or single. Then I found a TP5660 (56mm x 92mm) on OSE web page which say it produces 10K watts max. Should I start with a motor like this or something else. The boat is old and made out of fiberglass. It looks like it has a weed eater engine. Would maybe like to race in one day. There was a club her in San Antonio Texas before COVID but not sure if they are still here. Don't want to build this boat and break rules that will cost me money to correct. Will need help deciding other options. I have gone through the videos about calculating motor, and power but not sure what is the best options. I would appreciate any help you could provide.

The boat racing sanctioning bodies that I, and most people on this site race under, limit hull length to 60" and LiPo cell count to 10S. The boat would surely be fun to drive around, but is a bit large for racing that I know of.

By the way, one or two guys from San Antonio drive out to Katy once or twice a month and race with the club I'm a part of, HOTMBC (Heart of Texas Model Boat Club on Facebook). All we race are electric boats. Check us out.

[NativePaul]

A 72" boat is well outside my wheelhouse so I have no idea how much power it would take, but if your formula is right and its 8500W that motor won't be enough. Max power ratings are just for a few seconds for SAW use, if you want more than a few seconds runtime you need to use the continuous rating, which for that motor is 5500W.

[vvviivvv]

Take a look here,

Motors are rated at 34,000 watts in it... (for the pair)

https://forums.offshoreelectrics.com...uot&highlight=

my 72" twin build.

Still currently in paint, im offshore anyway until October.

[Doby]

Go with a decent gas engine.....you are going to spend a crap ton of money for very little run time making it electric..unless of course you want to spend a crap ton of money for very little run time. Plus you will never be able to "formally" race that size of a boat, electric or gas. Go gas and have fun with it.

[R2j2texas]

Thanks for the information. I will keep it gas and use it for the fun of it.