# CC's vs HP... Apples and Oranges?



## Dannoman (Jan 16, 2018)

In the old days, the snowblowers were rated by horsepower. Now it's CC's. What is the equal to a 10 HP machine in CC's or an 8 HP etc. Or are we comparing apples and oranges.


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## RedOctobyr (Mar 2, 2014)

You have to make sure of whether you're talking OHV or flathead engines. Everything nowadays is OHV, but mentioned just in case you're comparing with an older flathead. 

Tecumseh claims my 318cc OHV is 10hp, as one data point. Their ubiquitous HMSK80 318cc flathead was listed as 8hp. 

Honda has moved away from hp ratings, I believe, but their 270cc OHV used to be rated as 9hp. The 340cc was 11hp, the 390cc was 13hp.


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## GustoGuy (Nov 19, 2012)

RedOctobyr said:


> You have to make sure of whether you're talking OHV or flathead engines. Everything nowadays is OHV, but mentioned just in case you're comparing with an older flathead.
> 
> Tecumseh claims my 318cc OHV is 10hp, as one data point. Their ubiquitous HMSK80 318cc flathead was listed as 8hp.
> 
> Honda has moved away from hp ratings, I believe, but their 270cc OHV used to be rated as 9hp. The 340cc was 11hp, the 390cc was 13hp.


The newer OHV engines make more power per cc than do the older flat head engines too. I used to have a small flat head 5hp Tecumseh engine on my MTD 5/22 and while it got the job done it was never a powerhouse and it would bog big time when hitting the heavy snowplow packed snow at the end of the driveway when compare to the just 1.5hp more powerful on paper HF 212cc which was rated at 6.5hp. The new 212cc engine is a beast when compared to the old engine and with an impeller kit it actually throws snow 40 feet. Here is a video of it in action against 11 inches of snow.


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## 1132le (Feb 23, 2017)

GustoGuy said:


> The newer OHV engines make more power per cc than do the older flat head engines too. I used to have a small flat head 5hp Tecumseh engine on my MTD 5/22 and while it got the job done it was never a powerhouse and it would bog big time when hitting the heavy snowplow packed snow at the end of the driveway when compare to the just 1.5hp more powerful on paper HF 212cc which was rated at 6.5hp. The new 212cc engine is a beast when compared to the old engine and with an impeller kit it actually throws snow 40 feet. Here is a video of it in action against 11 inches of snow.
> 
> 
> https://www.youtube.com/watch?v=ONdFik8kges


Gusto ive watched your vid it throws great
the old 5 hp might have been 3.5 hp what was the rpms at 3100? most tecs very low ive owned a bunch
is the 212cc good yes does it make more stock then 6.5 hp and 8 ft lbs yes prolly
how much 10%? 20% maybe anything more No
can you mod it þo kiĉk a$$ yes
does it make 10ft lbs stock or 11 ño chance
my 8 hp fatty really around 6.8 hp
we all know the hp claims were bs
makes 12 plus ft lbs of torque
preditors run much higher rpms which spin the impeller much faster hence better throwing
my rust bucket st824 with impeller kit running 3725 rpm like all my tecs throws slop 30 feet and good snow 45 feet
impeller rpm is the gain not the magic hemi 212cc is the hemi nice but thats not the story honda showsthatwith there 1200 and 1350 rpm impeller speeds and less motor then ariensgx270
my 824 was 2800 rpm threw for crap uped by ear sounded like it was screaming checked it 3250 impeller rpm was barley above 1000 30 feet best throw
upped motor to 3725 rpm impeller 1090 rpm impeller kit 45 feet throws made it a beast
to say a 212cc stock has more power then a 8hp flatty is not right
i saw fearless with his vids he is running 4200 another 3900
impeller rpm makes the 212cc look much better
it still has trouble with lots of heavy wet bucket fulls compared to 318cc flatty with more ft lbs
displacement matters
before all you 212cc guys start writing all the ford vs chevy stuff
i like the 212cc ohv yes ohv makes more power
to say it makes more power then the 8hp flatty running right is disengenuios
3600 rpm plus or minus 150
ive run all mine there and they havent gone pop yet 
maybe the will ive been doing it for yrs
clean slighty over full oil running right it screams
the 212cc is a killer deal for 100 bucks and you can mod it for cheap
a good running 8 hp flatty at 3700 rpm is as well
Gusto i was not saying you said it made more then an 8 hp flatty
ive read it from the 212cc guys on this forum
this was a general post
i would never try and use a 5 hp tec anything to clear snow its under powered
and thee are others will say 5 hp is plenty
living on the coast of mass needs every bit of 12 hp or better for
4 plus feet of hard pack eod crap likes big motors


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## zandor (Dec 15, 2017)

I've heard there was some lawyer BS related to claimed HP and what they report to the EPA. Usually claimed HP is peak HP, like a car might claim 200hp @6200 rpm. The EPA version is some sort of complicated government mess involving averaging output at various engine speeds.

So bye bye standards, hello confusion.


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## Shryp (Jan 1, 2011)

zandor said:


> I've heard there was some lawyer BS related to claimed HP and what they report to the EPA. Usually claimed HP is peak HP, like a car might claim 200hp @6200 rpm. The EPA version is some sort of complicated government mess involving averaging output at various engine speeds.
> 
> So bye bye standards, hello confusion.



About 8 years ago or so there was a huge class action lawsuit going around. Basically they were trying to get anyone and everyone that bought anything with an engine on it in the previous 10 years or so to join.


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## tpenfield (Feb 24, 2015)

About the best correlation of old (HP) vs. new (cc) is that 32cc gets you about 1 HP. Not an absolute, but a decent approximation.

Similar to automobile engines, there can be changes in intake, exhaust, timing, etc that can get more or less power from a given size engine. I would imagine that rating engines in terms of displacement instead of power has made the the spec'ing of engines more absolute.


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## HCBPH (Mar 8, 2011)

tpenfield said:


> Similar to automobile engines, there can be changes in intake, exhaust, timing, etc that can get more or less power from a given size engine. I would imagine that rating engines in terms of displacement instead of power has made the the spec'ing of engines more absolute.


I've got a lCT 291 SnowForce engine in the box that says right on the box it's a 10 HP engine.
Do I believe it - maybe, maybe not.
As has been said, with vehicle engines there are a number of factors that can affect HP. About the only way to know for sure is if you could get one mounted to a dyno and see what it produces at any given RPM.
Even then, manufacturers played games with the numbers. Some used readings right off the crankshaft. Others used it measured at the rear wheel. Others did measurements with no accessories yet other included them.
As has been said previously, engines of the same displacement using older vs. newer can have a wide range of HP values noted. None are all right nor are all wrong. It just depends on who's generating the numbers.


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## GustoGuy (Nov 19, 2012)

HCBPH said:


> I've got a lCT 291 SnowForce engine in the box that says right on the box it's a 10 HP engine.
> Do I believe it - maybe, maybe not.
> As has been said, with vehicle engines there are a number of factors that can affect HP. About the only way to know for sure is if you could get one mounted to a dyno and see what it produces at any given RPM.
> Even then, manufacturers played games with the numbers. Some used readings right off the crankshaft. Others used it measured at the rear wheel. Others did measurements with no accessories yet other included them.
> As has been said previously, engines of the same displacement using older vs. newer can have a wide range of HP values noted. None are all right nor are all wrong. It just depends on who's generating the numbers.


 

NR Racing has tested stock Predator 212cc engines with the stock Honda style baffle mufflers at nearly 7.4HP right out of the box with out any modifications and with low restriction K&N conical style air filter with richer jetting were achieving 9hp with out any modification of the internal parts of the engine. Stage 1 kits from NR Racing found nearly 9.5 hp with out any internal modification of the engine. I hogged out the opening of my air box on my Predator 212cc and jetted the engine bigger and the bike became a wheelie machine. I needed to add 3 pieces of 3/8th inch thick plate steel one down low on the frame and 2 pieces over the number plate to prevent the bike from wheeling over when novice riders gun it because no matter how much I told them to lean forward they never would and the bike was downright dangerous to ride until I did this modification. Now it just goes forward instead of wheeling over.


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## tadawson (Jan 3, 2018)

At what RPM? Horsepower specs are typically listed at rated speed (typically 3600) and anything else is not terribly meaningful in comparison.


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## 1132le (Feb 23, 2017)

tadawson said:


> At what RPM? Horsepower specs are typically listed at rated speed (typically 3600) and anything else is not terribly meaningful in comparison.


The hp ratings were bs thats why they got rid of them
same engines 3 hp rating all different

torque is what matters for blowers


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## tadawson (Jan 3, 2018)

1132le said:


> The hp ratings were bs thats why they got rid of them
> same engines 3 hp rating all different
> 
> torque is what matters for blowers


Which is still listed at a specific RPM . . . still making my point valid, in that if similar conditions (RPM, whatever) are not used, the numbers are inckmparable BS . . .

And, considering that horsepower is torque multiplied by RPM, they are still related. For that matter, an engine putting out, say 10 ft-lbs of torque at 2750 RPM is clearly lower powered than one that does so at 3400 . . . (but, if the machine wants 2750, it would also be the clear choice, and also explains why diesels have such 'off the line' grunt (torque), but usually get killed at max speed (horsepower).)

Max torque is not always at max (or the desiredd operating) RPM, so it's important to note the RPM on that as well . . .


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## 1132le (Feb 23, 2017)

tadawson said:


> Which is still listed at a specific RPM . . . making my point valid.
> 
> Max torque is not always at max RPM, so it's important to note that as well . . .


Max torque is never at max rpm

hp is a function of torque

newer ohv valve motors usually between 2900 and 3100
most honda are at 2500 to 2850
old flat heads are around 2700 to 2850 ish
20 ft lbs at 3050 rpm are maybe maybe 18 ft lbs at 3600 rpm my engine 
414cc div by 32=12,93 hp
18x3600=64800 div by 5252=12.3 hp old way 20x3600=72000 div by 5252= 13.7 hp
my engine is turning 3835 rpm
nobody knows what the torque output is at 3600 rpm
all the motors were over rated before with the hp bs

my 2005 ohv 358 tec was rated @13hp @3750

358 div by 32=11.18 hp
it had 17 ft lbs 15.2 maybe at 3750 15.2x3750=57000 div by 5252=10.85


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## tpenfield (Feb 24, 2015)

There are several HP calculators online to check engine spec's.

1 horsepower = 550 ft.-lbs. / second or for rotational calculations it comes out to . . .

HP = ( Torque x RPM ) / 5252

Engines that have published torque spec's can be approximated fairly well, and if you have information on the torque curve, even better.

The nice thing is that most of these engines have a fairly flat torque curve in the RPM range of significance, which is usually around 2800 - 3600 RPM.

If I take my Briggs 1450 series engine that is spec'ed at 14.5 ft-lbs . . . I don't have the torque curve handy, but I can make some approximations. . .

If I'm getting the max torque (14.5 ft-lbs.) at about 3000 RPM, then it is capable of producing 8.28 HP @ 3000 RPM. 
If I'm getting only 13.5 ft-lbs. of torque at 3600 RPM, then it is capable of producing 9.25 HP at 3600 RPM

So, I guess in the old days it would be called a 9.25 HP engine. 

I also found an article about testing a 'stock' Predator 212cc . . . which made 9.83 HP @ 4700 RPM . . . the only thing is that they changed out the intake and the exhaust before testing it . . . so I guess it really wasn't completely 'stock' . . . here is the article. https://www.kartpartsdepot.com/product_p/001.htm

However, it does make the 6.5 HP stock spec. quite believable.


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## AbominableSnowman (Nov 14, 2016)

Here's a little bedtime reading on the subject for you all. Enjoy!

http://www.snowblowerforum.com/forum/general-snowblower-discussion/18545-discussion-engine-size.html

https://www.abbysguide.com/ope/discussions/59569-0-1.html

https://movingsnow.com/2008/cc-to-torque-to-hp-conversion-update/

http://www.snowblowerforum.com/forum/general-snowblower-discussion/17242-horsepower-print.html


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