Gas motor to electric motor swap

I have a hotsy machine at my shop that has a 16hp motor that blew a connecting rod. I want to put a electric motor in replace of it. Pump rpm is 1500 gpm 4.8 psi 3500. I only have single phase. Local electic motor shop told me a 10hp 1750 rpm motor would work but I am concerned with the pulley ratio. Right now I have a big one on the pump and small one on the motor.

I also would like to set up the hot water up to plug in to my power source when I hook up the motor. From what I gathered the motor put out ac voltage for the burner so I should be able to just wire that to a breaker and use the same switch on the machine?

One thing you have to remember is your gas engine was spinning at around 3400-3600 rpm. It’s the pulleys that reduce the rpm of the pump to 1500 rpm. With that being said you don’t want an electric motor that only has 1750 rpm. Imagine what would happen if your Vanguard was only spinning at half throttle? You wouldn’t be getting much flow or pressure coming out of your gun. Get an electric motor that puts out the same rpm as the gas engine or 3600 rpm. By doing so you shouldn’t have to change any pulleys. If for some reason you want a slower turning motor you’ll have to go much larger on the pump pulley. I have no idea what sizes you’d need but I imagine like twice the size on the pump.

A ten hp electric motor takes a lot to get turning so you’ll also want a magnetic starter with thermal overload. Otherwise it’ll just kick the breaker. is handy. It tells you wire size, breaker, and even tell you what size of magnetic starter you’ll need.

Another thing you’re probably going to have to swap out is the flow or pressure switches. This kicks the burner off when you’re off the trigger. The one or ones you have now are setup for 12v and not 110v. What kind of fuel pump does your burner have? Is it powered by a belt and pulley? If it’s a 12v pump you’ll also have to swap that out. You have to know what you’re doing so that burner turns off when you’re off the gun trigger. Otherwise the burner coils will continue to heat and eventually blow. It’s dangerous.

Be sure to add the price of everything up because you might be better off rebuilding the engine or slapping a new one on. You can get an 18hp clone for about $350 delivered. Cheap engine but I’m sure you don’t use the washer day in and day out so should last awhile. Duromax is the brand name. I threw one in our golf cart and have had good luck with it. It has a 2 or 3 year warranty. Just something to consider because it would be easier and cheaper. A 10 hp electric motor isn’t cheap. By the time you buy everything you’ll probably have more into than just sticking with a gas engine. You might just be better off fixing it up with an engine, selling it, and then buying one with a motor.

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Not really to concerned on the cost its at my farm and we have 3 pressure washers and seems like we can never keep them running when we need them. Want to go to all electric as the motors go out. The hot water will be something I will tinkle with once I have it set up.
I was thinking I would need to put a smaller pulley on the pump but maybe I am wrong.
I found a 12.5 hp 1800 rpm motor earlier.
I am a farmer and when we finish harvest I have 4 guys washing 3 with pressure washers and one with a 2 inch hose from the city line and it seems like I have to stay working on them all day from starter ropes carbs gas etc just want to eliminate some trouble. 2 of my pumps are pretty new otherwise I would trash it and get a big ectric one.

All 3 are down right now waiting on parts for the two good ones fuel trouble ordered new tanks for them. Had to go get my moms little electric 1200 psi pressure washer yesterday to clean a tractor up to find a leak. Was so nice to flip a switch and wash.
I will have a electron install a breaker box close to my wash slab and make sure he wires it big enough to add 2 more 5–10hp motors the other washers I have are smaller but want the option to go bigger if needed.

I keep trying to talk my buddy into buying a 5.5 gpm hot water for when they wash their farm equipment. He just keeps buying the little 2.5 hp cold water homeowner unit. He might actually have a little spare time if he had a hot water machine.

I don’t blame you for wanting electric if it stays in one spot. Like you said, a flip of the switch would be nice. Not having to listen to the noise from a gas engine running would be even better.

I don’t really know anything about electric washers or swapping from an engine to motor. It just seems like to me that if the gas engine was spinning at almost 3600 rpm and the pulleys are sized to that they should be the exact same size for an electric motor turning at 3600 rpm. I know hp or torque is different between gas engines and electric motors but rpm’s are rpm’s. It’s the pulleys that drop the pump’s rpm’s down to 1500 so it shouldn’t matter what’s power source you have as long as it’s turning 3600 rpm’s. Now if you did get a motor that only spun 1750 rpm’s that’s half of what the gas engine was turning so you’d have to change up the pulleys. If you’re not changing the engine or motor rpm there’s no reason to change the pulleys because that would change rpm’s to the pump.

I’ll tag Dezmar. He’s good at all this stuff. @dperez.

I only briefly read the responses so I’m not really all that present at the moment.

A 7.5hp motor should get it, just watch the amp draw at start up. 10’s are just too much money so run a 7.5 and open up your nozzle if you’re crowding it. It should have the nads to spin it though. 1750 rpm at the drive so just double the sheave size. And your burner needs 12vdc not 110vac

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Could he just use a motor that spins at 3600 rpm and use the current pulleys that were used with the 16 hp Vanguard? Or are you just thinking less wear and tear on a motor that spins at the lower 1750?

As far as 12v for the burner what’s the best thing to do? A 12 vdc transformer or little power converter?

Yes, but the 3600 rpm motors won’t last anywhere near what the 1750’s will. Look at the 1750 motors like the HD diesel version. Not industrial like 3 phase motors but they have way more duty in them then the 3600’s.

$20 convertors on eBay

Something like a 20amp 120 watt should get it.

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What would my pulley ratio need to be if I go with a 10hp 1750ish motor
I am even open to going with a 12hp single phase motor there is only one that I can find. I will have a electrician wire the motor up correctly with a

Measure the o.d. of your drive pulley you have now and just double it.

Wouldn’t I need to keep it close to the same size just a tad bigger. The gas motor spun around 3600 and pump is 1500 if this electric motor is 1750.
Just wondering if i’m thinking about this all wrong or not.

Don’t worry about the driven end just look at it as the drive end was spinning twice as fast as it once was. You’ll need to double that speed to put you at 3500 IF they had the engine pullied to run flat out at 3600. To be honest I’d just run a calculator and replace both sheaves to get everything exact but if you just double it on the drive in it will be good enough for gooberment work with out the added cost and calculations.

It’s just best to measure out everything you have and start from there with a pulley calculator. I don’t know what you had installed or what you have laying around. Borrow pulleys from friends/family and you’ll find something you like that you can replace for them.

@Case215 Hey I was thinking why don’t you just run matched sheaves and over speed your pump 250 rpm? Your pump is more than good for it and you’ll squeeze two more cups of water out of it :joy:

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I ain’t following, I believe non E fuel and some seafoam would cure his situation without going through all this. IMO.
I run gasser,diesel pumps,hay bailers, chicken spreaders etc,etc randomly all year. Hell the rice field boys run their stuff for 2 weeks to flood the fields, Sea foam then tarp it till next season.

Sorry I’m late to this I may have missed it but is your burner 110 or 12v. How do you plan on running the electric motor. The last thing you want to do is plug it into a customers house.

He’s a farmer and uses them on his own farm implements and other equipmenr. The washers his has all stay in one place. @dperez has him all lined out on everything.

LMAO this is the greatest ha

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Golly, You doing alright ? Do I need to summon @Infinity for grammar lessons sir, This is twice now in less then 3 days, Just a concerned uneducated rubber scrubber is all.

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