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Posted by salty on October 11, 2009, 5:06 pm
On Sun, 11 Oct 2009 10:26:37 -0400, "Worn Out Retread"
show/hide quoted text
>> On Sat, 10 Oct 2009 11:19:38 -0400, salty@dog.com wrote:
>>>wrote:
>>>>>I am looking for a new snow blower and have discovered that the power
>>>>>rating of the engines are no longer in "Horse Power" but in "Foot
>>>>>Pounds"
>>>>>if given at all. Sometimes all that is given is the CC's of the engine.
>>>>> Even the people selling these machines don't know what the "Horse
>>>>> Power"
>>>>> ratings are so that old geezers like myself can understand what is
>>>>> going
>>>>> on. Does anyone have any general rules regarding the conversion of Foot
>>>>> Pounds or CC's to Horse Power?
>>>>Horsepower to CC is highly variable and not a good measure of power. My
>>>>cars have different engines. The 3800 cc is 190 HP but my 3300 cc is 234
>>>>HP. I suspect smaller engines are similar.
>>>For the types of engines generally found on lawn equipment, comparison
>>>of new engines and old engines of same brand and displacement is a
>>>valid comparison. These are utility engines designed to run at optimum
>>>RPM's while in use. A car engines is vastly different in it's
>>>requirements.
>>>If an old snowthrower with a 13 hp Briggs engine is 350cc, then a new
>>>350cc Briggs powered snow blower will be about the same HP.
>> Unless the old 350cc 13hp Briggs is a "side valve" engine with 5.6:1
>> compression ratio, and the new 350cc engine is an overhead valve
>> engine with 11.5:1 compression ratio - which MIGHT be a 18HP engine.
>> Numbers just picked out of thin air, but the principal is there.
>This is perfectly true. Engines of the same displacement can vary greatly in
>power developed due to the ratio of diameter of piston to the length of
>stroke, valve configuration, exhaust tuning and other factors.
But in THIS category of engines, that isn't generally a factor. Old
and new Briggs utility engines of the same displacement will also have
similar power characteristics.
You probably won't find a snowblower with a turbo option, and lowered
suspension, either.
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Posted by clare on October 11, 2009, 10:11 pm
On Sun, 11 Oct 2009 17:06:26 -0400, salty@dog.com wrote:
show/hide quoted text
>On Sun, 11 Oct 2009 10:26:37 -0400, "Worn Out Retread"
>>> On Sat, 10 Oct 2009 11:19:38 -0400, salty@dog.com wrote:
>>>>wrote:
>>>>>>I am looking for a new snow blower and have discovered that the power
>>>>>>rating of the engines are no longer in "Horse Power" but in "Foot
>>>>>>Pounds"
>>>>>>if given at all. Sometimes all that is given is the CC's of the engine.
>>>>>> Even the people selling these machines don't know what the "Horse
>>>>>> Power"
>>>>>> ratings are so that old geezers like myself can understand what is
>>>>>> going
>>>>>> on. Does anyone have any general rules regarding the conversion of Foot
>>>>>> Pounds or CC's to Horse Power?
>>>>>Horsepower to CC is highly variable and not a good measure of power. My
>>>>>cars have different engines. The 3800 cc is 190 HP but my 3300 cc is 234
>>>>>HP. I suspect smaller engines are similar.
>>>>For the types of engines generally found on lawn equipment, comparison
>>>>of new engines and old engines of same brand and displacement is a
>>>>valid comparison. These are utility engines designed to run at optimum
>>>>RPM's while in use. A car engines is vastly different in it's
>>>>requirements.
>>>>If an old snowthrower with a 13 hp Briggs engine is 350cc, then a new
>>>>350cc Briggs powered snow blower will be about the same HP.
>>> Unless the old 350cc 13hp Briggs is a "side valve" engine with 5.6:1
>>> compression ratio, and the new 350cc engine is an overhead valve
>>> engine with 11.5:1 compression ratio - which MIGHT be a 18HP engine.
>>> Numbers just picked out of thin air, but the principal is there.
>>This is perfectly true. Engines of the same displacement can vary greatly in
>>power developed due to the ratio of diameter of piston to the length of
>>stroke, valve configuration, exhaust tuning and other factors.
>But in THIS category of engines, that isn't generally a factor. Old
>and new Briggs utility engines of the same displacement will also have
>similar power characteristics.
>You probably won't find a snowblower with a turbo option, and lowered
>suspension, either.
The difference between a side valve and overhead valve engine of any
displacement in any application is generally considerable.
It IS a factor, as anyone who is fammiliar with small engines will
know.
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Posted by salty on October 12, 2009, 6:24 am
On Sun, 11 Oct 2009 22:11:11 -0400, clare@snyder.on.ca wrote:
show/hide quoted text
>On Sun, 11 Oct 2009 17:06:26 -0400, salty@dog.com wrote:
>>On Sun, 11 Oct 2009 10:26:37 -0400, "Worn Out Retread"
>>>> On Sat, 10 Oct 2009 11:19:38 -0400, salty@dog.com wrote:
>>>>>wrote:
>>>>>>>I am looking for a new snow blower and have discovered that the power
>>>>>>>rating of the engines are no longer in "Horse Power" but in "Foot
>>>>>>>Pounds"
>>>>>>>if given at all. Sometimes all that is given is the CC's of the engine.
>>>>>>> Even the people selling these machines don't know what the "Horse
>>>>>>> Power"
>>>>>>> ratings are so that old geezers like myself can understand what is
>>>>>>> going
>>>>>>> on. Does anyone have any general rules regarding the conversion of Foot
>>>>>>> Pounds or CC's to Horse Power?
>>>>>>Horsepower to CC is highly variable and not a good measure of power. My
>>>>>>cars have different engines. The 3800 cc is 190 HP but my 3300 cc is 234
>>>>>>HP. I suspect smaller engines are similar.
>>>>>For the types of engines generally found on lawn equipment, comparison
>>>>>of new engines and old engines of same brand and displacement is a
>>>>>valid comparison. These are utility engines designed to run at optimum
>>>>>RPM's while in use. A car engines is vastly different in it's
>>>>>requirements.
>>>>>If an old snowthrower with a 13 hp Briggs engine is 350cc, then a new
>>>>>350cc Briggs powered snow blower will be about the same HP.
>>>> Unless the old 350cc 13hp Briggs is a "side valve" engine with 5.6:1
>>>> compression ratio, and the new 350cc engine is an overhead valve
>>>> engine with 11.5:1 compression ratio - which MIGHT be a 18HP engine.
>>>> Numbers just picked out of thin air, but the principal is there.
>>>This is perfectly true. Engines of the same displacement can vary greatly in
>>>power developed due to the ratio of diameter of piston to the length of
>>>stroke, valve configuration, exhaust tuning and other factors.
>>But in THIS category of engines, that isn't generally a factor. Old
>>and new Briggs utility engines of the same displacement will also have
>>similar power characteristics.
>>You probably won't find a snowblower with a turbo option, and lowered
>>suspension, either.
> The difference between a side valve and overhead valve engine of any
>displacement in any application is generally considerable.
>It IS a factor, as anyone who is fammiliar with small engines will
>know.
Absolutely not a consideration in a snowblower engine, which is run at
two speeds. Stopped and Full Throttle.
Don't bother with a reply unless it actually applies to snowblower
engines specifically. Hint: Snowblowers are not motorcycles.
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Posted by clare on October 12, 2009, 3:11 pm
On Mon, 12 Oct 2009 06:24:16 -0400, salty@dog.com wrote:
show/hide quoted text
>On Sun, 11 Oct 2009 22:11:11 -0400, clare@snyder.on.ca wrote:
>>On Sun, 11 Oct 2009 17:06:26 -0400, salty@dog.com wrote:
>>>On Sun, 11 Oct 2009 10:26:37 -0400, "Worn Out Retread"
>>>>> On Sat, 10 Oct 2009 11:19:38 -0400, salty@dog.com wrote:
>>>>>>wrote:
>>>>>>>>I am looking for a new snow blower and have discovered that the power
>>>>>>>>rating of the engines are no longer in "Horse Power" but in "Foot
>>>>>>>>Pounds"
>>>>>>>>if given at all. Sometimes all that is given is the CC's of the engine.
>>>>>>>> Even the people selling these machines don't know what the "Horse
>>>>>>>> Power"
>>>>>>>> ratings are so that old geezers like myself can understand what is
>>>>>>>> going
>>>>>>>> on. Does anyone have any general rules regarding the conversion of Foot
>>>>>>>> Pounds or CC's to Horse Power?
>>>>>>>Horsepower to CC is highly variable and not a good measure of power. My
>>>>>>>cars have different engines. The 3800 cc is 190 HP but my 3300 cc is 234
>>>>>>>HP. I suspect smaller engines are similar.
>>>>>>For the types of engines generally found on lawn equipment, comparison
>>>>>>of new engines and old engines of same brand and displacement is a
>>>>>>valid comparison. These are utility engines designed to run at optimum
>>>>>>RPM's while in use. A car engines is vastly different in it's
>>>>>>requirements.
>>>>>>If an old snowthrower with a 13 hp Briggs engine is 350cc, then a new
>>>>>>350cc Briggs powered snow blower will be about the same HP.
>>>>> Unless the old 350cc 13hp Briggs is a "side valve" engine with 5.6:1
>>>>> compression ratio, and the new 350cc engine is an overhead valve
>>>>> engine with 11.5:1 compression ratio - which MIGHT be a 18HP engine.
>>>>> Numbers just picked out of thin air, but the principal is there.
>>>>This is perfectly true. Engines of the same displacement can vary greatly in
>>>>power developed due to the ratio of diameter of piston to the length of
>>>>stroke, valve configuration, exhaust tuning and other factors.
>>>But in THIS category of engines, that isn't generally a factor. Old
>>>and new Briggs utility engines of the same displacement will also have
>>>similar power characteristics.
>>>You probably won't find a snowblower with a turbo option, and lowered
>>>suspension, either.
>> The difference between a side valve and overhead valve engine of any
>>displacement in any application is generally considerable.
>>It IS a factor, as anyone who is fammiliar with small engines will
>>know.
>Absolutely not a consideration in a snowblower engine, which is run at
>two speeds. Stopped and Full Throttle.
>Don't bother with a reply unless it actually applies to snowblower
>engines specifically. Hint: Snowblowers are not motorcycles.
See my later post. I have not been talking motorcycles. I've been
talking lawn mowers and snow blowers.I have been a small engine
mechanic. Worked for an Ariens dealer back before OHV small engines
were available. Have also been an auto mechanic for many years. Have
owned and worked on flatheads as well as OHV and OHC engines and I
know the difference, and the advantages VERY well.
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Posted by dpb on October 10, 2009, 11:04 am
Worn Out Retread wrote:
show/hide quoted text
> I am looking for a new snow blower and have discovered that the power
> rating of the engines are no longer in "Horse Power" but in "Foot
> Pounds" if given at all. Sometimes all that is given is the CC's of the
> engine.
>
> Even the people selling these machines don't know what the "Horse Power"
> ratings are so that old geezers like myself can understand what is going
> on. Does anyone have any general rules regarding the conversion of Foot
> Pounds or CC's to Horse Power?
Unfortunately, not at all precisely, no...thanks to the dam lawyers :(
One can _VERY_CRUDELY_ estimate hp at about 60-70% of torque.
The relationship I recall (I'd have to go off and think again to
re-derive the denominator) of hp ~ torque (ft-lb)*rpm/5250 which boils
down to the above since most ratings are at 3200-3600 rpm.
Unfortunately, that's about best one can do other than simply try to
find similar engine w/ known rating and compare based on displacement.
Problem there is that tune and emissions requirements, etc., make that
comparison as variable as the above.
Earlier Northern Tool catalog still listed an unofficial "old hp rating"
as well but I just looked and the last one doesn't. Now I'm hoping I
didn't throw the old one away and lose that cross-reference.
All in all, it sucks to guess how to compare even worse than before when
ratings could be tweaked--at least you knew what Sears was doing w/
"peak" or "instantaneous" horsepower; the torque ratings might be
absolutely accurate but they're still nearly useless as a comparison to
previous ratings and certainly there's not even the same measure used if
only provide displacement in one and torque in another.
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Page 3 of 13 < 1 2 3 > last >>
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>>>wrote:
>>>>>I am looking for a new snow blower and have discovered that the power
>>>>>rating of the engines are no longer in "Horse Power" but in "Foot
>>>>>Pounds"
>>>>>if given at all. Sometimes all that is given is the CC's of the engine.
>>>>> Even the people selling these machines don't know what the "Horse
>>>>> Power"
>>>>> ratings are so that old geezers like myself can understand what is
>>>>> going
>>>>> on. Does anyone have any general rules regarding the conversion of Foot
>>>>> Pounds or CC's to Horse Power?
>>>>Horsepower to CC is highly variable and not a good measure of power. My
>>>>cars have different engines. The 3800 cc is 190 HP but my 3300 cc is 234
>>>>HP. I suspect smaller engines are similar.
>>>For the types of engines generally found on lawn equipment, comparison
>>>of new engines and old engines of same brand and displacement is a
>>>valid comparison. These are utility engines designed to run at optimum
>>>RPM's while in use. A car engines is vastly different in it's
>>>requirements.
>>>If an old snowthrower with a 13 hp Briggs engine is 350cc, then a new
>>>350cc Briggs powered snow blower will be about the same HP.
>> Unless the old 350cc 13hp Briggs is a "side valve" engine with 5.6:1
>> compression ratio, and the new 350cc engine is an overhead valve
>> engine with 11.5:1 compression ratio - which MIGHT be a 18HP engine.
>> Numbers just picked out of thin air, but the principal is there.
>This is perfectly true. Engines of the same displacement can vary greatly in
>power developed due to the ratio of diameter of piston to the length of
>stroke, valve configuration, exhaust tuning and other factors.