Displacement
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Torque moves cars horsepower sells them. Why exactly did engines from the 20's come up? I should damn well hope that a newer smaller engine makes as much, or more, horsepower. We have had over 100 years to develop the internal combustion engine, wheras they had <u>maybe</u> 30. If technology is the replacement for displacement then why are race teams, drag teams in particular, using massive V8 engines? With all the technology the top teams have access to why aren't they building small inline 4 motors, or even small V8 motors for that matter. The arguement that RPMs are a replacement can be made, i.e. indy cars, but what are you doing when you run an engine at higher RPM. Moving more air into and out of the engine, pretty my the same thing as using a bigger one in the first place. Except with a bigger one you don't have to put as much time into making it hold together so its cheaper.
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capitlj;213341 wrote:
Torque moves cars horsepower sells them. Why exactly did engines from the 20's come up? I should damn well hope that a newer smaller engine makes as much, or more, horsepower. We have had over 100 years to develop the internal combustion engine, wheras they had <u>maybe</u> 30. If technology is the replacement for displacement then why are race teams, drag teams in particular, using massive V8 engines? With all the technology the top teams have access to why aren't they building small inline 4 motors, or even small V8 motors for that matter. The arguement that RPMs are a replacement can be made, i.e. indy cars, but what are you doing when you run an engine at higher RPM. Moving more air into and out of the engine, pretty my the same thing as using a bigger one in the first place. Except with a bigger one you don't have to put as much time into making it hold together so its cheaper.Why don't they use V12s or bigger if displacement is the best thing ever??? 8 cylinders is the magical number i guess??
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8 cylinders is (generally) the largest practical motor you will fit in most engine bays....aside from that, it is readily available already so the whole concept doesn't need to be redesigned. Then there is the cost factor of a larger block, 33% more pistons, re-engineering the cams/crank/etc... Then, there are class restrictions and other obstacles when it comes to professional racing which can limit the displacement and/or the number of cylinders allowed.
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zbrown;213379 wrote:
yes HP is determined from TO and RPM............. but a car's acceleration G's is directly proportional to the HP curve .......... not the TO curveWrong. A car will accelerate exactly matching its torque curve, not its horsepower curve. A car will accelerate hardest at its peak torque.
300 foot pounds of torque will accelerate you just as hard
at 2000 rpm as it would if you were making that torque at 4000 rpm in the
same gear, yet, per the formula, [HP= (Torque * RPM) /5252] the horsepower would be double at 4000 rpm. -
you are correct accel. G's match the TO curve directly not the HP
horsepower is still the determining factor in the rate of acceleration of any vehicle though
http://www.yawpower.com/tqvshp.html
really good article, there was a second more in depth section but do you think i could find it
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inspector01;213354 wrote:
Why don't they use V12s or bigger if displacement is the best thing ever??? 8 cylinders is the magical number i guess??Chuck touched on this lightly but 8 <u>is</u> sort of a "magic" number. An 8 cylinder four stroke engine has two cylinders on the "power" stroke at any given time vs a 4 cylinder engine which only has one. Why is it you think a V12 ferrari with 500 hp feels different than a V8 ford with 500 hp. Its because the engine has three cylinders on the "power" stroke at any given time so its power delivery is smoother, although it does not have any more power than the V8 engine.
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OK, so what you are saying that more displacement isn't necessarily better?? OK, thank you very much.
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capitlj;213438 wrote:
Chuck touched on this lightly but 8 <u>is</u> sort of a "magic" number. An 8 cylinder four stroke engine has two cylinders on the "power" stroke at any given time vs a 4 cylinder engine which only has one. Why is it you think a V12 ferrari with 500 hp feels different than a V8 ford with 500 hp. Its because the engine has three cylinders on the "power" stroke at any given time so its power delivery is smoother, although it does not have any more power than the V8 engine.I'd rather have the non-smooth power delivery of a 500hp 4cyl...
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^^^agreed.
my honda was slow
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