[DH1]

Been going through some manuals and found some interesting specs.

Tecumseh
HH80 8hp rating 384cc flathead
HH100 10hp rating 384cc flathead
OH140 14hp rating 388cc OHV -40% more hp than the 10, 75% more hp than the 8.

China Honda clones
13hp rating OHV 389cc

I don't know how long ago Tecumseh made these engines (40 years ago?) but they were able to get more power with OHV technology than a 2010 China made engine of the same size.
So I ask whats better?
Or is it all about the $, manufacturing cost, and having something new that will sell???
I've used 4 of the clone engines on different things and the biggest difference I notice is they are quieter, better muffler.

 

[NUTNDUN]

I think a lot of the reason for the power differences is because of the emission standards. Then as far as anything else goes it is all about the money. The clones can be had sometimes for half the price which to a lot of consumers that is very important. I wouldn't be afraid to run a clone but as long as I have the old iron I will keep running them. I have thought about getting one of the diesel clones sometime for a project but that is a couple years away.

 

[poncho62]

Hard to compare engines unless you put them on the same tractor......I have 10 hp Tecumseh and Kohler flatheads on my MF and Ford.....Have a 13 hp Chinese knockoff on my National Mower......I am sure either of the 10 hp ones could outpull the 13 hp......Just the sound of them seems more powerfull.....Chug, chug, chug as compared to that tinny sound....lol

 

[mikebramel]

yeah you cant really compare the horsepower but you have to compare the stroke of the motor because the stroke is really where the torque (twisting force) comes from

 

[DH1]

Sure you can
Honda clone - 389cc makes 13hp
Tecumseh flathead - 455cc makes 12hp
At low rpm the larger engine is going to have more torque, the only reason the smaller engine has more hp is OHV, better breathing at high rpm which is where hp measurements are taken.
You have the same situation for Tecumseh OHV engines made 30-40 years ago.

 

[hitempguy]

I found that the 11hp clone engine I had worked very well. Good on fuel and easy to start. Seemed to make good torque as well, definitely smoother. Why the balancer shaft snapped, I don't know... We'll see how the 13HP one lasts.

 

[hitempguy]

Here are some specs for the clone vs Tecumseh

--------------HH100-----------HP11 Clone-----HH120--------HP13 Clone
------------------------------Honda GX 340 ----------------Honda GX 390
Bore: --------3 5/16------------- 3.25---------- 3.50--------- 3.54
Stroke: -------2.75-------------- 2.50---------- 2 7/8---------2.50
Displacement: 23.7/388cc-------- 340cc------ 27.66/453cc---- 390cc

All engines rated at 3600 RPM, so the smaller engine is not making power like a ricer mobile, through RPM
Based on this info, the Tecumseh's would probably make even more "horse"power if the heads were the more efficient overhead design and way more torque with the HH 120 having 13% more stroke(agreeing with DH1 and mikebramel)
I would agree that the Tecumsehs' would "pull" a lot better, even with a lower HP rating

 

[teyhan1]

Hi. This is my first reply since becoming a member. I run a small garden machinery business in the U.K. We see alot of these copy engines coming through our shop and all I ever say about them is that they are rubbish. I refuse to sell anything that I cannot back-up and these engines are notoriously bad to obtain spares for. On top of this the chinese understanding of metalurgy leaves a great deal to the imagination. hitempguy has no idea why his balancer shaft snapped. I DO.
Why doesn't China stun us all and come up with something good (like Zama carbs) that is designed and manufactured in China with pride and engineering excellence instead of stealing everyone else's ideas and making western con men rich.:mad2:

 

[mjodrey]

teyhan1 :welcometogttalk:glad to have you here.

 

[caseguy]

teyhan1, :wave:! Welcome to the forum...and I agree! Just to add my $.02 to the discussion, The mass of the moving parts also factors in to the torque of any given system. The newer engines are made of lighter weight materials by and large and that actually takes away from the torque they can develop.