Horsepower?

WOULD THIS BE THE WAY TO FIND HORSEPOWER IF I DIDNT HAVE A DYNO AND ONLY KNEW THE TORQUE THE RPM AND THE NUMBER OF CYLINDERS

YES I NO THERE IS A DYNO AND THERE IS A FORMULA BUT I THOUGHT THE FORMULA WAS WRONG BECAUSE FIRST I FOUND TWO TORQUExRPM/(5252 OR 5254)

SO HERE IS A SETTING

THERE IS A 4 CYLINDER ENGINE SPINNING AT SAY 60 RPM(I NO THIS IS NOT A REAL FIGURE) WITH 10 FT LBS OF TORQUE PER CYLINDER

SO THERE IS ONE FIRE OF THE SPARK PLUG EVERY 90 DEGREES ROTATION OF THE CRANKSHAFT AND EACH FIRE PRODUCES 10 FT LBS OF TORQUE SO IN A SECOND THERE IS 40 FT LBS OF TORQUE CREATED NOW MULTIPLY THAT BY 3600 AND U GET 144000 NOW DIVIDE THAT BY 33000 AND U GOT URE ANSWER SO 4.36 HP

IS THAT A CORRECT EQUATION?( I REPEAT I NO THERE IS A DYNO I JUST WONDERING I M A VERY CURIOUS PERSON)

IF YOU CAN SUPPLY ME WITH SOME TORQUE GRAPHS AND CYLINDER NUMBER OF SOME CARS THAT WOULD BE GREAT AS WELL AS ANSWERING THIS QUESTION

SERIOUS ANSWERS PLEASE

Help.! My motor won't start!?



Answers:    whelp, that looks okay in premise, but there's a few holes in it. For starters, the number of cylinders is irrelevant when discussion about horsepower - typically power is calculated from an engine, as a adjectives.

Horsepower is a measure of applying a force over a distance.

Torque = Work
Rate at which work is done = RPM
Horsepower = power

to divide power, it's Torque * RPM / 5250

the 5250 is not some lame number outta nowhere either, it's in fact arrived at by taking 33,000 (1 horsepower) divided by (3.14 x 2) = 5252.11312 - rounded to 5250 as a constant in the automotive industry.

Let's progress a bit further with your multiplication.

a 4 cylinder 4-stroke engine will fire one piston every 180 degrees of crank rotation, a 4 cylinder 2 stroke engine will fire one every 90 degree of crank rotation.

so anyhow, based on what you originally said 60 RPM, near 10 ft. lbs of torque per cylinder would be 40 ft. lbs. of torque, at 60 RPM's

40 * 60 = 2400 units of work.

2400 unit of work / (33000 / (PI *2)) = 0.465 horsepower

what I don't understand is where on earth the multiplication of 3600 would come from, and then why you're dividing by 33000 - are you trying to subtract up 3600 RPM's? Unfortunately, you can't calculate torque base on a lower RPM - Torque is something that's created based on the success of an engine, you'd have to subtract SO many variables (like Volumetric use, engine size, etc) to figure out the torque produced by that engine, from that weighing up, you'd be able to arrive at a modest horsepower estimation.

that's a VERY basic explanation. and when I say aloud VERY basic, I plan very, ultra, bottom of the butt explanation.

My van is not starting properly?


There is no equasion because all engine are built different. in that is also the fact that you loose horsepower through the drivetrain(trans, reverse differential). Therefore, your engine would have more horse by itself than whats calculated through the drive wheels(as on a dyno test)

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