morehorsepower
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This is true that's why I said in my previous post that torque gets you moving horsepower get you going faster.
Lo 206 comp psi
- Thread starter Popatopracing
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This is true that's why I said in my previous post that torque gets you moving horsepower get you going faster.
alvin l nunley
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Torque x RPM / 5252.1 = HP. Horsepower; it's a name given to the sum of a calculation.
From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory.(Al Nunley
spud majic
New member
my guess is you would see about 100psi if the comp release is out of the way. less than 80 and most engines have a very hard time starting. leakdown takes a few minutes if you have the setup ready to go. its more informative than compression check.
our karts are not horses. we have gearing. this equals out high rpm and low rpm engines. that is essentially what hp tells you. a 2 strokes makes way less torque at 12k. but they run a lot more gear. really want to see effective power? torque x gear ratio. the torque curve at rear wheels is what matters.
our karts are not horses. we have gearing. this equals out high rpm and low rpm engines. that is essentially what hp tells you. a 2 strokes makes way less torque at 12k. but they run a lot more gear. really want to see effective power? torque x gear ratio. the torque curve at rear wheels is what matters.
In which case I apologize. I thought you could pull the recoil off without breaking the seal.
If you're SUPER eager to get a compression PSI reading I guess you could weld/lock an old clutch, mount the motor and spin it with a strap around the axle.
To see if its leaking anywhere just whip the valve cover off, release the rockers so the valves seal, put it at BDC, apply compressed air via spark hole a listen to leakage. A little past the rings is normal, a lot isnt good. Valve ideall will have near-perfect seal but again a little seep wont hurt.
While Al is absolutely correct that "horsepower" is just a name given to something derived form a calculation that results from torque, (I think) I kind of get what you're saying.
Normally you get your bigger torque numbers at lower rpm... it "gets you going".
The only way you get "BIG" horsepower numbers is if you continue to see "BIG" torque numbers at higher rpm... it "gets you going faster"... even if the reality is that it's the torque that's still applied at the higher rpm - and not the horsepower, per se - that gets you going faster.
alvin l nunley
Site Supporter
10 x 5252.1 / 5252.1 = 10 HP
the two 5252.1s cancel each other so you get
10 x cancel / cancel = HP
10 lbs torque = 10 HP
spud majic
New member
a lot of people mistake hp with a engines ability to rev quickly. an engine under full load may make 10ft lbs at 4k without changing rpm. but in low gearing where the rpm is changing quickly a lot of that energy is absorbed in rotational inertia and may only produce an effective 8ft lbs as it revs through that range. engines with high hp gerenally make torque at higher rpm which means they tend to rev faster giving the impression that hp=acceleration. this is why on a dyno most cars will make more power in 3rd or 4th gear. and why turbocharged cars wont hit peak boost until 2nd or 3rd gear.
alvin l nunley
Site Supporter
Torque x RPM / 5252.1 = HP
horsepower, as you can see, is a calculation. The more torque, at any given RPM, the more horsepower. In all cases, more horsepower will result in faster acceleration!
The rest of the post is so bewildering, I must refrain from saying anything.
From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory.(Al Nunley
spud majic
New member
i would ask you to dyno a car in 2nd gear and then in 4th gear and tell me they make the same power curves at each condition... for a real life example my car makes 400ftlbs wtq and 300whp in 4th gear. it only makes about 280whp in 2nd gear. one dyno run is in no way a means to determine engine power dynamically through the opperation conditions of an engine. my engine is a "torquey" engine, meaning it makes lower torque in the high rpm range than at the low end and thus lower peak hp. therefor my engine tends to not rev hard in lower gears both in reality and in theory which is apparent by the 20whp drop. my post was to point out how some people come to a conculsion of how hp equates to speed and torque moving weight dispite that being untrue... hence back to my earlier comment of "the torque curve at rear wheels is what matters" this is what is used to determine shift points in race cars in real life conditions. its what actually matters.
Of course they do. Mathematically, they HAVE to... it all goes back to the calculation that Al keeps referring to. It's really not complicated at all.
Take 2 engines, both max torque of 10 ft-lbs, but that 10 ft lbs of torque comes at 2 different rpm points:
10 lbs torque at 5252 / 5252 rpm = 10 hp (at 5252 rpm)
10 lbs torque at 10504 rpm / 5252 = 20 hp (at 10504 rpm)
spud majic
New member
no they dont. you can make high hp at low rpm which obviously requires lots of torque down low(this is how my 2.5 liter car makes 300hp at 4500rpm) however most engines arent built this way. most make hp in the high rpm range simply because its easier to do so. adversly a n/a 2.5 that will spin up to 9000+ will make 300hp and wont make peak torque until a much higher rpm.
Of course you can make high hp at low rpm... and yes, it is harder to do.
But take your engine that makes 300 hp at 4500 rpm (350 ft-lb torque @ 4500), and apply that same 350 ft-lb torque at a higher rpm, and your hp number is higher than your 300 hp... math.
Therefore, of course "engines with high hp generally make torque at higher rpm".
alvin l nunley
Site Supporter
if an engine makes peak torque at a high rpm, that's where it's going to make the most horsepower. Look at the formula, (which I repeat time and time again); torque x RPM / 5252.1 = HP. Can you not see that! Peak torque – high rpm – horsepower. Do you not understand that horsepower is a calculation! It's a word used to describe the "Work" being done.
"5252.1", do you know where that number comes from? Wikipedia will tell you. Do you know where the term horsepower comes from? Do some research on James Watt. If I work at the rate of one horsepower, (550 pounds one foot in one second) for one minute, I will have done 33,000 pounds feet of work. There are 2pi radians in a circle. Divide 33,000 by 2pi radians, (6.283185307) and you get 5252.1.
From the desk of Al Nunley
Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory.(Al Nunley
spud majic
New member
al i know the formula... at no point did i ever state ANYTHING that doesnt support that... you just keep implying it... PS YOU CAN MAKE PEAK TORQUE AT LOW RPM AND STILL MAKE PEAK HP AT HIGH RPM. hp rises as rpm increases if torque stays the same. we both know this. however i can show you numerous instances of people with the same car as me who make peak torque at 3500rpm and peak hp at 7500. where as mine makes it at 4500. their torque curve maintains at a slow diminishing rate due to VE loss but peak torque point is still peak torque. i would attest that you probably arent familiar with these types of conditions because you dont work with variable valve timing or turbos but nevertheless that doesnt discount the fact that they are possible. which goes back to what i said originally. torque x gear ratio for each gear ratio in a gearbox or gear change in a single speed situation= functional comparison of acceleration and shift point calculations.