New engine--18 hp for $300

[KartFab123]

Has anybody tried this engine ? It looks like a great deal. I might try it on a project

http://www.homedepot.com/p/Duromax-...erhead-Valve-Portable-Engine-XP18HP/206799897

 

[anickode]

I kinda get the feeling that 18 hp is a drastic overrating, or the 440cc bit is a misprint on home depot's part.

An engine of that size should be in the 12-14 hp range. It would be odd for an 18 hp engine to have electric start as an option, as opposed to standard.

I'm betting it's just an over-rated Chinese motor.

 

[KartFab123]

Yea it looked like it could be to good to be true.

 

[itsid]

I kinda get the feeling that 18 hp is a drastic overrating, or the 440cc bit is a misprint on home depot's part.

An engine of that size should be in the 12-14 hp range. It would be odd for an 18 hp engine to have electric start as an option, as opposed to standard.

I'm betting it's just an over-rated Chinese motor.

I disagree... the duromax is IIRC a lifan really.. yes a gx clone just like the preadtor is,
but not inferior to it ... let's just put it that way.

So yeah, buy it if you like!

the 18hp is also a plausible rating.

the 420cc duromax always had 16hp.. I don't see why another two aren't possible

And yes, I know the predator cannot compete with the hp..
but the predator is just another cheap chinese clone..
maybe this one has slightly more oomph.

'sid

 

[anickode]

Could be... I know the Honda GX440 (when they made it) was rated 15hp. Plausible I suppose, but I would still guess that rating is based on parameters outside of its normal scope of operation.

Kind of like how my shop vac says 2.5 hp and draws 11 amps on 120v. If connected to a 30 amp circuit and the motor is loaded down to the point of burning out, that motor *might* make 2.5 hp for an instant before it fails.

 

[Kansaskart]

Theres threads dating back years on this forum people asking about duromax. Ive also wondered.

Do us all a favor and buy it. Take the govenor off and let us know how it goes. Lol.

I know im gona want a bigger engine on my project in the competition forum eventually. Its not a safe build to have a high top end so I was thinking one of these and leave the govenor on it. With 18hp I should be able to use a smaller sprocket and get close to 40 and still have power. Or hoping.

 

[itsid]

motors have always been tested without airfilter and exhaust AFAIK,
so yeah it is kindof a stretch
(Honda no longer does that IIRC they changed they're mechanism a while back)

And electric motors and engines are not comparable.. not AT ALL!

a shop vac likely not talks about hp as you know it but about an
air rating (watts) which they then converted to hp (for some douche reason)

And air ratings are just insanely misleading (1200W air rating can be achieved with as little as 400W mechanical power or ~600 W electrical power)

or the vac allows to run from a 220V line as well.. then it'll push 2.5hp at least drawing 11amps.
IDK, frankly IDC much

But truth is, the predator is only great for ONE reason : it's cheap!
it's not actually predatory in the beasty sense ... if it'd be an animal it's more a sheep than a wolf if you know what I mean

Anywhoo.. Lifan 420 makes 15 horses with CA compliance... (close to 16 w/o)
the Kohler command ch440 with CA compliance close to 16 (15.7 or something)
different jets, slightly different airfilter and just 200 more rpms (3800 instead of 3600) and you should see 18 IMHO.

So I still call the hp rating plausible
(I can't tell I don't have a duromax nor a dyno to test it)

'sid

PS the iGX440 has a rating of 13hp alright.. the gx200 of the same year 5.5hp btw...
the gx390 not quite 11hp (10.7)
early gx200 had a rating of 7, gx390 a rating of 14.5 (IIRC) and all they changed was the way they measure AFAIK.

 

[anickode]

motors have always been tested without airfilter and exhaust AFAIK,
so yeah it is kindof a stretch
(Honda no longer does that IIRC they changed they're mechanism a while back)

And electric motors and engines are not comparable.. not AT ALL!

a shop vac likely not talks about hp as you know it but about an
air rating (watts) which they then converted to hp (for some douche reason)

And air ratings are just insanely misleading (1200W air rating can be achieved with as little as 400W mechanical power or ~600 W electrical power)

or the vac allows to run from a 220V line as well.. then it'll push 2.5hp at least drawing 11amps.
IDK, frankly IDC much

But truth is, the predator is only great for ONE reason : it's cheap!
it's not actually predatory in the beasty sense ... if it'd be an animal it's more a sheep than a wolf if you know what I mean

Anywhoo.. Lifan 420 makes 15 horses with CA compliance... (close to 16 w/o)
the Kohler command ch440 with CA compliance close to 16 (15.7 or something)
different jets, slightly different airfilter and just 200 more rpms (3800 instead of 3600) and you should see 18 IMHO.

So I still call the hp rating plausible
(I can't tell I don't have a duromax nor a dyno to test it)

'sid

PS the iGX440 has a rating of 13hp alright.. the gx200 of the same year 5.5hp btw...
the gx390 not quite 11hp (10.7)
early gx200 had a rating of 7, gx390 a rating of 14.5 (IIRC) and all they changed was the way they measure AFAIK.

Yeah, I'm well aware. I was just using it as a comparison to show how they can get reeeeeaaaal creative with their rating techniques.

 

[KartFab]

So I dug more into this and here are the REAL important numbers (not hp because its bs). You cant fake max torque, and it usually always peaks around 2500ish rpm, and trails off from there so it keeps everybody somewhat 'honest'. TORQUE MATTERS.

Max Torque
predator 420 18.4 ft-lb (420 cc)
honda gx340 19.5 ft-lb (337 cc)
honda gx390 19.5 ft lb (389 cc)
duromax "16" hp 21 ft-lb (419 cc)
duromax "18" hp 21 ft-lb (440 cc)
predator 670 33.19 ft -lb ("22 hp") (670cc)
honda gx 630 35.6 ft-lb (20.8 hp) (688 cc)

So as you can CLEARLY SEE with torque

1) duromax probably over-rated their torque, and it probably only has in all likely-hood 18ish ft lbs. The website i pulled the info from had the EXACT salesy 'capable of up to 21 ft lbs torque" line in the description.... like im capable of being a millionaire, doesnt make me one though...
2) "horsepower" is severely underrated with hondas, and/or outright BS with duromax

P.S. I prefer hondas.
P.P.S. knockoffs usually under perform the original123
P.P.P.S Heres a chart that one could use to estimate a more realistic "HP" of engine based on displacement alone, using honda ratings for the gx200, gx390, and gx630 as the standard (assuming linear relationship between hp and displacement)

This puts things a bit more into perspective
predator 420 =12.2 hp honda hp
duromax "16hp" =12.2 hp honda hp
duromax "18 hp" =12.7 hp honda hp
predator "22 hp" =20 hp honda hp

 

[Kansaskart]

I have read a few complaints of the rod seizing to the crank but those were without the govenor. Thats why I just stick to predators. They are field tested. I was hoping by now the other ones would get some info out. Of course everyone likes hondas but pretty apparent why many of us dont have them. I have a couple but I got them used. If I spent $800 on one for one of my 'toys' , as my wife calls them, she wouldnt be real happy unless it was attached to a powerwasher. So I just piece together predators here and there lol.