QuestionI have an old self propelled, walk behind, lawn mower with a 6.25 hp Briggs %26 Stratton engine. New mowers are now rated by torque or cc, and instead of hp. How can I tell if a new mower is likely to be at least as powerful, or more, as the old one.
AnswerHello Jim:
>>I Located this Information on CC to HP Conversion Online a Few Years ago;
>>The Formula that works best only applies to the small newer normally aspirated (carburetor) 4 cycle engines.
>>The ratios change slightly worse with altitude and slightly better with fuel injection and tuning. Most American mowers and the newer 4 cycle outboard motors fit into one of these two formulas:
>>Typical new (carburetor) engine well tuned:
1 x HP per each 25 cc
>>Fuel injected:
1 x HP per each 22 cc
>>Note:
>>Most engines are tuned down to a lower HP for better engine life.
>>It is common for the same cc engine to be built in 3 different HP versions with the highest rated being the maximized HP per cc version. That is how you see price and HP changes on the same cc engine made by the same company.
>>Some of the newest (2008 and newer) engines from Japan perform slightly better.
>>A typical 150cc motor should equate to between 3.5 - 6 HP+ depending on tuning with 5 HP being the adv.
>>The Actual Formula plots as a Curve and Not Linear but does not apply to Max/High Performance engines like motorcycles.
>>If you Hit a Snag or this Does Not Correct the Problem, I Hope to be Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 5 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Comments and Ratings are Greatly Appreciated. Thanks.
Respectfully
John
