Predator 212/420 durability

Messages
6
Location
West Virginia
Just got an idea and had some questions. I live off grid with free natural gas. My NG is free but the well has limits and if I use to large of a generator, it sucks water out of the well and pressure drops. I have an excellent high efficiency inverter charger that handle some pretty huge loads. I don't much care for high rpm generators or even inverter generators because of the possible finicky electronics. I have a 24 volt 300 amp military niehoff alternator. Weighs about 60-70 lbs so I am pretty sure its a true 300 amps continuous. I plan on running it at a lower speed and only using around 140 amps tops. Does anyone know how long a predator 212/420 will last at a lower rpm? I've seen people on youtube saying they have over 3000 hours on the generator so i figure 1800-2000 rpm should be a breeze for the engine. Most likely will be a steady state 1800-2000 rpm. Any modification I can do to help engine life? I may put a K&N filter on it and remove the smog box filter and replace with just a regular filter for it so no nasty crankcase air going in. Extra zinc? 120/300 bucks right now but the long it lasts, the lower the running costs. I might put a big old box fan or blower on it to make it cool. I will remove the gas tank as well since i won't need it. I would prefer pressure lubricated so I could put a external oil cooler with thermostat in and a bypass of some kind. I just can't justify something that expensive though that might not last. v twins costs as much as rebuilt car engines. Most of these modifications can be reused if the engine nukes itself. Thoughts?
 
Messages
718
Location
MN
I'd run it as it comes out of the box. Under light load they won't get hot, you will want the larger motor. Do not put a K&N filter on it, they're actually really crappy at filtering out fine dust which is what will kill your rings in the long run. Change the oil every 1-200 hours after the first 2-3 50hr changes and use a good HD oil. When the motor eventually dies they're cheap enough to just stick a new one in and being that you left it stock it'll be that much easier and quicker to do so. I'd want filtering on the fuel source for sure, NG can get kinda dirty. Definitely a moisture trap at a minimum.
 

Deveak

Thread starter
Messages
6
Location
West Virginia
I was thinking about the K&N because its reusable and lowers long term costs. I will be using this a LOT. most likely 1000+ hours a year. I do have a moisture trap but is there a way to passively filter the well gas?
 
Messages
4,445
Location
Massachusetts
I don't know about exact longevity, but I installed a Predator 212 on my log splitter 3 years ago and it's been working great. It starts on one pull in summer, and maybe 2-3 pulls in the dead of winter. We burn for heat. I don't have an hour meter, but it gets used often. At about $100.00, it's been a great replacement engine. You could probably fab additional air filtration. The fan inside the pull start seems to cool the unit just fine. You could test running conditions with an IR gun if you have one. I think HF sells those too.
 
Messages
12,492
Location
North Carolina
I think the predator engines are straight shaft, a lot of generators need a tapered shaft. Investigate your generator head before you buy an engine.
 
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Messages
6,346
Location
Connecticut
Originally Posted by spasm3
I think the predator engines are straight shaft, a lot of generators need a tapered shaft. Investigate your generator head before you buy an engine.
+1
 
Messages
3,014
Location
USA
24 volts at 140 amps is 3.4 kWe, which would require at least 4.4 hp from the engine assuming 100% conversion efficiency. This proposed "light load" is actually near the rating of that little engine, so expect to run it to rated rpm.
 
Messages
2,312
Location
WY
Run a hit and miss possibly or magneto low rpm one lunger from the 1920-1940s off of the natural gas and use the flywheel to spin a generator 24/7. Go to some old tractor or equipment show and see what's out there.
 
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Deveak

Thread starter
Messages
6
Location
West Virginia
Originally Posted by spasm3
I think the predator engines are straight shaft, a lot of generators need a tapered shaft. Investigate your generator head before you buy an engine.
I am going to belt drive it, its a 28 volt alternator, not a generator head. spline shaft, will take some adapting.
 

Deveak

Thread starter
Messages
6
Location
West Virginia
Originally Posted by mk378
24 volts at 140 amps is 3.4 kWe, which would require at least 4.4 hp from the engine assuming 100% conversion efficiency. This proposed "light load" is actually near the rating of that little engine, so expect to run it to rated rpm.
Yeah thats why I am leaning more towards the 420. The alternator I have should be higher efficiency, I think around 70-80% instead of the usual 50-60%. I call it a light load because 99% of the time its going to be 1 kw or less.
Originally Posted by sloinker
Run a hit and miss possibly or magneto low rpm one lunger from the 1920-1940s off of the natural gas and use the flywheel to spin a generator 24/7. Go to some old tractor or equipment show and see what's out there.
I thought about that but its likely to cost 3-4x as much, I will have no idea how to service it and parts availability is non existent.
 

Deveak

Thread starter
Messages
6
Location
West Virginia
I bought the engine today for 400. I got the two year warranty for 10 bucks. Not sure if its any good but I might be able to run the dog [censored] out of it in two years and see what happens. I got a hold of the alternator manufacturer. Its a niehoff N1375. 2000 rpm is peak efficiency, 75-76% efficient which is actually a lot higher than I was expecting. Probably from the fact that its a 6 phase alternator. I think I can do a 1:1 connection than. I can't find torque curves for the motor but its a clone of the gx 390 with slightly more displacement and it lists the torque at 18.4 ft lbs of torque at 2000 rpm. The predator is listed at a peak of 18.4 at 2500 so I think they should be pretty close if not the same.
 
Messages
71
Location
South Dakota
The Predator engines are stupid reliable. I have five 212cc Predators in my garage powering all kinds of stuff from my snowblower to mini bikes. The mini bikes probably get abused the absolute worst and the one issue I EVER had was um..... operator related...

For setup it is very simple. I highly recommend changing the oil twice at the beginning: once at one hour and a second at two hours. The reasoning for this is all of the glitter and unicorn pee that flushes out. After that you can run it darn near forever. Leave the engine stock. Leave it absolutely stock. It's not a racer, it's not on a kart, just leave it alone. It will not overheat. The oil will be fine without pressurization or filtration. For your application a Preddy 420 will only last for about seventy continuous years.
 
Messages
33
Location
Shelton, CT
24 volts at 140 amps is 3.4 kWe, which would require at least 4.4 hp from the engine assuming 100% conversion efficiency. This proposed "light load" is actually near the rating of that little engine, so expect to run it to rated rpm.
You beat me to it. The calculator was in my hand.
 
Messages
957
Location
Pennsylvania
Does iridium plug make any difference in these engines?
I can't say for sure, but I did replace the factory plug with a NGK Iridium plug at the time of first oil change on my Predator 3500. I was pleasantly surprised to find a Bosch plug in it, although the number looked more like the typical Torch brand you find in Chinese engines. The only case where I can say that a spark plug made a difference was in a 254 cc LCT engine on an Ariens snowblower. That thing refused to run well on the factory Torch brand plug, and was nearly impossible to start. Now it purrs like a kitten with the NGK Iridium.
 
Messages
71
Location
South Dakota
Those engines will last forever. For that application just leave it stock. You could rig up a 55 gallon barrel of gas and run at 1/2 throttle for months on end. I don't have a 420 but I've bought six 212s for various projects plus I have three other GX200 "clone" engines. The Predator engines are a rather good Honda clone with a cast iron bore that should last thousands of hours with proper maintenance. I use a standard NGK plug and Rotella T6 oil.
 
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