Duromax 274cc

Have any of you seen this new Duromax 274cc engine?

I just discovered it last night, it looks more similar to small block than a big block, it looks to have the typical 6 bolt side cover of a small block, and the mounting pattern is the same as a small block. On the other hand it has the 1” output shaft of a big block.

According to Duromax it weighs 42 pounds, compare that to a Predator 212, which according to Harbor Freight weighs 34 pounds, a predator 301 weighs 57 pounds according to HF, a Honda GX270 weighs 25.8 kg, which equates to 57 pounds.

As for bore / stroke, Duromax claims a 75mm bore and 62mm stroke, a Honda GX270 has a 77mm bore and 58mm stroke. So this new engine has a smaller bore but a longer stroke than GX270, it also weighs quite a bit less than a GX270.

So, I don’t know what to think, is it big block or is it a small block? Looks and weighs similar to a small block, but has the 1” shaft of a big block. Either way pretty interesting.

It’s also worth noting, that on GFO’s website the description states:

“The DuroMax XP9HP is one of our most compact and lightweight engines available”…

The website also shows it on a mini bike a couple times, perhaps they were trying to make an engine that would be more compact for those kinds of applications.

Here’s the links to Duromax and GFO, if anyone wants to check it out.

Duromax: https://www.duromaxpower.com/collec...274cc-25mm-shaft-recoil-start-gasoline-engine

GFO: https://www.generatorfactoryoutlet....274cc-25mm-shaft-recoil-start-gasoline-engine
 
Technially (kart speaking) it's a small block since it bolts up like one. I'd like to take one apart and check it out.
 
Have any of you seen this new Duromax 274cc engine?

I just discovered it last night, it looks more similar to small block than a big block, it looks to have the typical 6 bolt side cover of a small block, and the mounting pattern is the same as a small block. On the other hand it has the 1” output shaft of a big block.

According to Duromax it weighs 42 pounds, compare that to a Predator 212, which according to Harbor Freight weighs 34 pounds, a predator 301 weighs 57 pounds according to HF, a Honda GX270 weighs 25.8 kg, which equates to 57 pounds.

As for bore / stroke, Duromax claims a 75mm bore and 62mm stroke, a Honda GX270 has a 77mm bore and 58mm stroke. So this new engine has a smaller bore but a longer stroke than GX270, it also weighs quite a bit less than a GX270.

So, I don’t know what to think, is it big block or is it a small block? Looks and weighs similar to a small block, but has the 1” shaft of a big block. Either way pretty interesting.

It’s also worth noting, that on GFO’s website the description states:

“The DuroMax XP9HP is one of our most compact and lightweight engines available”…

The website also shows it on a mini bike a couple times, perhaps they were trying to make an engine that would be more compact for those kinds of applications.

Here’s the links to Duromax and GFO, if anyone wants to check it out.

Duromax: https://www.duromaxpower.com/collec...274cc-25mm-shaft-recoil-start-gasoline-engine

GFO: https://www.generatorfactoryoutlet....274cc-25mm-shaft-recoil-start-gasoline-engine
Landon and Mike, i got one that hot rodded and did couple mods to it. stroke the crank some more to a 67mm and only punch it out to a 76mm bore and change the intake to a 34mm, ported the head, milled...etc.. 13.1, 30mm round slide Mikuni , turn the crank down to a 3/4/ keyway and YES technically it's a small block frame. runs like a freight train. just on race gas now with a 320 main, so yes it does have little power...lol. might try it out this summer for flat track racing. we will see.
 

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