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-   -   "cc" "hp" "torque"??? (https://www.rcuniverse.com/forum/rc-giant-scale-cars-234/7242316-%22cc%22-%22hp%22-%22torque%22.html)

da mad maori 03-18-2008 01:08 AM

"cc" "hp" "torque"???
 
ive been building rc boats with 2stroke engines for years and now own a hpi baja 2stroke
i know how the engines work but one thing that stumps me is how the cc rating relates to hp and to a lesser extent torque

i had 2 rc boats, one with a 32cc talon engine (cheapie) and one with a 26cc zenoah both stock and both boats weighed the same yet the talon produced 0.9hp and the zen produced 3.5hp! and the zen killed the "cheaper" talon

i also have a 15' halfcabin runabout (real boat) that has a 2Hp evanrude auxilary engine which when i did use it it pushed my 15' boat quite nicely YET if i put a zenoah 6hp engine on it........well it wouldnt move obviously

SO whats the deal?
what do you look out for?

im thinking compression ratio has something to do with it... you can have the same size chamber but one might compress more....meaning bigger boom....meaning more down force....meaning more power???
i dont know.... please disscus
:)


Ryan

Foxy 03-18-2008 02:58 AM

RE: "cc" "hp" "torque"???
 
HP is how hard you hit the wall, torque is how much of the wall you take with you. There's no replacement for displacement, as they say, but I'd wager that the Zen killed the 32 because it was well ported, and probably had higher compression (as you suggest, and yes, more compression does mean bigger bang and more power).

splcrazy 03-18-2008 03:45 AM

RE: "cc" "hp" "torque"???
 
is there a way to run a piston on the baja5b motor that has two rings instead of one , would a two ring piston have more compression than a single ring piston ?

da mad maori 03-18-2008 03:53 AM

RE: "cc" "hp" "torque"???
 
thought as much
so buy that, yould be looking for the cc rating (and quality of course)
i compared them buy thinking, the zen cost me 5 times more than the talon so it BETTER out perform it lol

Ryan

da mad maori 03-18-2008 04:00 AM

RE: "cc" "hp" "torque"???
 
splcrazy;

not really. the reason most "4strokes" engines have more than 1 ring is that they have engine oil at the bottom that the "oil" ring keeps out...
2 strokes dont have engine oil so it only needs the one compression ring

the way to get more compression is to shave the cylinder which you'ld have to enlongate your ports etc..... not recommended.. there are easier ways... like twin turbos LOL

Ryan

splcrazy 03-18-2008 04:22 AM

RE: "cc" "hp" "torque"???
 
has anyone done a turbo on a baja5b yet lol , thers more than enough exhaust pressure for it lol, ive got the rear DDM pipe and revving it up, the exhaust pressure blasted me in the face lol

beer=food 03-19-2008 05:45 AM

RE: "cc" "hp" "torque"???
 
hahahaha ! LOL !
Turbo on baja = megga dollars into drive line, yes ?
The whistle would be awsomely sweety though, have to admit !

da mad maori 03-19-2008 06:45 AM

RE: "cc" "hp" "torque"???
 
:) it would sound pretty sweet wouldnt it??

wen wen nen weeeeeeeeennnnnnnnnnnnnnnnnnnnnnnnwwwwwiiiisssssss ssssssssssssssssssssss 'BOOM'

LOL

Ryan

jtnktz 03-19-2008 11:07 AM

RE: "cc" "hp" "torque"???
 


ORIGINAL: da mad maori

:) it would sound pretty sweet wouldnt it??

wen wen nen weeeeeeeeennnnnnnnnnnnnnnnnnnnnnnnwwwwwiiiisssssss ssssssssssssssssssssss 'BOOM'

LOL

Ryan

That didn't sound funny until I actually read it. :p

Lunar Wolf 03-19-2008 06:12 PM

RE: "cc" "hp" "torque"???
 
Ever since the term "Horsepower" was invented it has always been a PR number or marketing tool - nothing more.

da mad maori 03-19-2008 08:34 PM

RE: "cc" "hp" "torque"???
 
yep ild agree with that lunar wolf
the measurement originally meant the power of one horse pulling a cart... but has changed since then
one horse can pull ALOT harder than a 1hp engine...

Ryan

Lunar Wolf 03-20-2008 03:36 AM

RE: "cc" "hp" "torque"???
 
The average horse can't sustain 1HP for long periods, its an intresting term anyway.


[edit] History of the term "horsepower"
The term "horsepower" was coined by James Watt to help market his improved steam engine. He had previously agreed to take royalties of one third of the savings in coal from the older Newcomen steam engines.[8] This royalty scheme did not work with customers who did not have existing steam engines but used horses instead. Watt determined that a horse could turn a mill wheel 144 times in an hour (or 2.4 times a minute). The wheel was 12 feet in radius, therefore the horse travelled 2.4 × 2π × 12 feet in one minute. Watt judged that the horse could pull with a force of 180 pounds (assuming that the measurements of mass were equivalent to measurements of force in pounds-force, which were not well-defined units at the time). So:


This was rounded to an even 33,000 ft·lbf/min.[9]

Others recount that Watt determined that a pony could lift an average 220 pounds 100 feet (30 m) per minute over a four-hour working shift. Watt then judged a horse was 50% more powerful than a pony and thus arrived at the 33,000 ft·lbf/min figure.

Engineering in History recounts that John Smeaton initially estimated that a horse could produce 22,916-foot-pounds per minute. John Desaguliers increased that to 27,500-foot-pounds per minute. "Watt found by experiment in 1782 that a 'brewery horse' was able to produce 32,400-foot-pounds per minute". James Watt and Matthew Boulton standardized that figure at 33,000 the next year.[10]

Put into perspective, a healthy human can produce about 1.2 hp briefly (see Orders of magnitude (power)) and sustain about 0.1 hp indefinitely, and trained athletes can manage up to about 0.3 horsepower for a period of several hours.

Most observers familiar with horses and their capabilities estimate that Watt was either a bit optimistic or intended to under promise and over deliver; few horses can maintain that effort for long. Regardless, comparison to a horse proved to be an enduring marketing tool.


[edit] Horsepower from a horse
R. D. Stevenson and R. J. Wasserzug published an article in Nature 364, 195-195 (15 July 1993) calculating the upper limit to an animal's power output. The peak power over a few seconds has been measured to be as high as 14.9 hp. However, for longer periods an average horse produces less than one horsepower.

http://en.wikipedia.org/wiki/Horsepower


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