Chainsaw Repair

Chain - Grinders - Filing - Wood Milling - Tools - Welding - Machinist - Mowers - Tillers => Mowers Tillers Tractors etc => Topic started by: Cut4fun . on February 01, 2015, 09:14:39 am

Title: CC v/s HP
Post by: Cut4fun . on February 01, 2015, 09:14:39 am
Ok I am still old school on this stuff and confuses me when I want to know the hp size of something now days when it is listed in cc.

Talking gas motors like it used to be.  1.5hp 2hp 3hp 3.5hp 5hp 12hp etc etc. That way I know what size something is on a push mower, riding mower or snow blower etc.

I am starting to see everything in cc that is newer. If I ask what hp would that be folks selling dont even know.

So just trying to get some ballpark info put together to be able to do comparisons of hp and cc.


Title: Re: CC v/s HP
Post by: Cut4fun . on February 01, 2015, 09:17:06 am
Reasons why for new cc figures.

copy paste

Manufacturers have always given max. HP ratings, just like auto makers. But mower engines have a 'speed limit' of about 3200 RPM for safety reasons. So, an engine that produces 6.5 HP at 3600 RPM will produce less at the mandated lower speed. Duh. As long as everyone uses the same rating method, a 7.0 HP rating would always mean a more powerful engine than a 6.0 HP rating. So after a bunch of whiney-cats sued them, they now have to give torque ratings (usable work) instead of HP ratings.
The 'cc' number is cubic centimeters of displacement, or the 'size' of the engine. All things being equal, a larger engine makes more power. Currently, mower engines have grown to about 190 to 195 cc as a result of the horsepower war brought about by the trend toward mulching and self-propelled mowers.
So, if you need a very powerful snow blower, go by the rating and displacement, although the two do not necessarily go hand in hand.

Title: Re: CC v/s HP
Post by: Cut4fun . on February 01, 2015, 09:19:23 am
copy paste

cc to horsepower

    Snowblower season is now upon us. Going to buy a new snowblower this year? But you don't know how powerful it is? Here is an approximate cc to horsepower chart for small engines. This chart ONLY gives an IDEA of how much horsepower CAN BE achieved by a stock engine of that CC size. There are too many variables, such as carb size, muffler flow, timing, valve duration. Some of these were taken from ads that stated "replacement 179 cc engine for 5hp snowblowers". This just lets you know that a 179cc engine can NOT be a 10 hp engine. Hope this helps in deciding which snowblower you buy.

    123 cc = 4 hp
    179 cc = 5 hp
    208 cc = 5.5 to 6 hp
    277 cc = 7 to 8 hp
    291cc = 9hp
    305 cc = 9 to 10 hp
    342 cc = 11 to 12 hp
    357 cc = 13 hp
    420 cc = 13-15 hp
Title: Re: CC v/s HP
Post by: Cut4fun . on February 01, 2015, 09:21:00 am
Dont know if this info is right or not but gives me something to start at.

copy paste

It is hard to convert cc to H.P. on the engine specs they usually now tell you max kW at what rpm

1 hp = .75kW,
and 1 hp. = 550 foot pounds per second, of torque.

On a mower or for that matter a outboard motor where you are spinning a blade or propeller torque is more important than horse power.
Title: Re: CC v/s HP
Post by: Cut4fun . on February 01, 2015, 09:22:38 am
I been living under a rock it seems.

cc to torque to hp Conversion Update November 2014

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

123 cc = 4 hp
179 cc = 5 hp
208 cc = 8 to 9 Gross Torque = 5.5 to 6 hp
277 cc = 11 to 11.5 Gross Torque = 7 to 8 hp
305 cc = 13.5 to 14.5 Gross Torque = 9 to 10 hp
342 cc = 15.5 to 16.5 Gross Torque = 11 to 12 hp
357 cc = 14 hp
420 cc = 15 hp
Title: Re: CC v/s HP
Post by: RoyM on February 01, 2015, 01:14:33 pm
It does get confusing especially for the consumer who has no clue about torque or cc's and the manufacturers only add to it. Briggs replaces the very common 21M314-0017 with the 20M307-0001 service engine and some complain they are getting a less powerful unit. I highly doubt anyone would notice in the real world but it is one cu inch smaller.
Title: Re: CC v/s HP
Post by: srcarr52 on February 01, 2015, 11:48:31 pm
Honda GX200, 196cc, 21hp. Just a little modified drinking alcohol.
Title: Re: CC v/s HP
Post by: 660magnum on February 02, 2015, 01:32:09 am
I have several B&S push mower variations and they all have the 6.75 ft lb torque engine. 190cc or 11.6 ci.

 I like them very well.

Tonight I went to the B&S website and they had a torque curve chart for that engine series. The 6.75 ft lbs torque is at 2600 rpm.

I looked at what torque they have at 3600 rpm where the engine normally runs and converted that to horse power.

They are 4 hp at 3600 rpm. This doesn't sound as impressive as 6.75 ft lbs torque?
Title: Re: CC v/s HP
Post by: fuzz1500 on February 11, 2015, 06:12:48 pm
I hate thst they have gone away from hp ratings :(
Title: Re: CC v/s HP
Post by: Al Smith on April 06, 2015, 03:50:20 pm
Briggs had a tendency to fudge the HP ratings.I have for example several 18 HP horizontal oppossed flat heads rated at 18 HP .Seems funny I also have one,same model and displacement rated at 19.5 HP .
Title: Re: CC v/s HP
Post by: Cut4fun . on January 03, 2017, 02:36:04 pm
TTT needed this again to find some info.