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Discussion Starter #1
What would be an affordable motor to replace a 140hp inboard Chevy motor for a boat. It’s a 16ft closed bow with 780lb hull. I’m wanting to run some good lithium packs and install dolor over the closed bow and do a Bimini top with solar over the passengers. I’m wondering if a warp 9 would be sufficient.
 

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I would not use a brushed DC motor in a boat. Boats require a lot of continuous power, and brushed DC motors although very good at peak power have very low continuous power since they cannot be liquid cooled (this is because unlike AC motors most of the heat is developed in the rotor). In addition, they typically are not well sealed to the environment which I would think would be a requirement on a boat.

Also: What RPM do you need? This is important on an inboard.
 

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What about a hyper 9 then
That's closer. It's better sealed but still only IP56. I think it does have higher continuous power, but might be a little underpowered compared to what you are taking out.

You really need to get the torque curve for the inboard engine. The gear reduction is going to be what it is going to be, so torque and RPM are more critical than just HP numbers. If the Hyper9 is developing power at a higher RPM than you can run at, then you're going to definitely not have the torque you want.
 

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The gear reduction is going to be what it is going to be, so torque and RPM are more critical than just HP numbers.
Yes, unless you add a gearbox (or belt drive), or the existing gearbox is changed. Extra mechanical complexity is not good, and staying with existing gearing is simpler and easier, but if a change saves buying a much larger motor, it may be worthwhile.
 

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Yes, unless you add a gearbox (or belt drive), or the existing gearbox is changed. Extra mechanical complexity is not good, and staying with existing gearing is simpler and easier, but if a change saves buying a much larger motor, it may be worthwhile.
Regardless he's going to need to know those numbers to design any changes to the reduction, so really what we need is for him to figure out those numbers and then we can see what's available.
 

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With watercraft, you have the additional option of changing the prop(wheel) diameter and/or blade pitch to accommodate the power/torque output of the motor. Do you have a true inboard, or a sterndrive (inboard/outboard)?
 

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Discussion Starter #10
It’s a a inboard Chevy 140 hp inline four with a merc outdrive. It says the stock motor has a 4400-4800 rpm max. I was really hoping a warp 9 could handle this.
 

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A forklift motor is going to be basically the same thing as a Warp9 or Warp11 if you find a DC one. So, if you're going DC, then you might as well save some money and buy a forklift motor for $100-200 instead of thousands. However, see Hollie's not above about the unsuitability of a DC motor for a boat.

If you find a newer forklift they'll have AC motors, you could use one of those instead, but you'd need an AC inverter to make it spin (no easy spinning like with DC where you just hook up a car battery temporarily).
 

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Discussion Starter #14
I have been finding low mileage leaf motors from 400-800$ on eBay. Looks like there’s 1st and 2nd gen . I’m thinking of buying a second gen.
 

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I would maybe do a larger inverter. The Prius inverter cant put out as many amps as the OEM Leaf inverter, maybe get a Leaf inverter, a Lexus gs450h, or Chevy Volt inverter. Without as many amps you will be down on power.
 

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Discussion Starter #17
Well I bought a 23,000 mile leaf motor and inverter, Charger. I’m wondering do I have to run leaf batteries. I would like about a 150-170hp any battery suggestions
 

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You're going to want high voltage to get the most out of the Leaf kit you bought. A Leaf battery is 96S - so try and stick to this cell-count. Definitely lithium over lead - unless you can get practically free, practically new lead acids.

Best bet is to use an OEM car pack - will be the best value. Chevy Volt batteries aren't too pricey - Small so you may need more than 1, but doable. A Leaf pack might work - though the cells do degrade quite badly, so if you do spring for one - make sure it's in good health first. Tesla batteries are expensive, but the best for power density (though on a boat, this is probably a non-issue - you should have plenty of room).

New cells are possible if you find the right deal - but that is rare.
 

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Discussion Starter #19
Is it not a good idea to make my own lithium system. What would be a good cell and how many would make sense to get about 150hp, I wouldn’t be on throttle all the time some is spent just sitting on the lake and fishing.
 

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It’s a a inboard Chevy 140 hp inline four with a merc outdrive. It says the stock motor has a 4400-4800 rpm max. I was really hoping a warp 9 could handle this.
The Warp9 can handle that RPM range. Get a good solid controller like a Zilla.
 
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