2.5/3.5 Displacement not giving as hp

[Zerep]

i was reading road & tracks 08 buyers guide and they rated the accord coupes 2.4 liter engine at 200bhp and the altimas 2.5 at 170bhp and the accords 3.5v6 was also rated 3bhp higher then our vq35z(270) now i always thought higher displacement meant more horse power, but it might mean just more torque or both. also i like to add that the accords 4banger was tested at 7000rpm which made me think they did not say at what rpm the altima coupe was tested at. so if anyone would be nice enough to answer what gives.
Modified by Zerep at 3:31 PM 3/2/2008

[Rmuth25]

as an american muscle enthusiast will tell you...."there is no replacement for raw displacement"

[Rmuth25]

Oh and you answer your question, no bigger engine displacement does not always mean more horsepower. THere are alot of other factors like compession, as well as the quality of pistons, cams and headers that have to factor into an engines output. Think of it this way, the newer cars the engines keep getting smaller but the horsepower keeps going up comparaed to cars like 20 years ago. I had a 3.1 liter chevy corsica(which they put that 3.1 6 cylinder in alot of their cars), and I think it would be generious to rate that car 145 horses.

[Rmuth25]

Besides for me, the real important number is torque

[Zerep]

thanks for the response and do you think that the 2.5 can get the same numbers by allowing it to reach the higher rpms

[Buzzman]

thanks for the response and do you think that the 2.5 can get the same numbers by allowing it to reach the higher rpms

As mentioned above, HP and displacement are 2 different things, and they are generally not related. Just look at all the different outputs of the 3.5 engine. Every model has a different HP output.Secondly, a bit of info on the 2.5 engine: It is not a high reving engine, and never will be, in it's current state. It red lines at just over 6K for a reason. (This topic came up in the Sentra forum as well by the way.)This engine has a long stroke, compared to the bore. As a result, piston speed becomes an issue at higher revolutions. When this engine is spinning at around 6K, the pistons are traveling at the same speed as most 4 bangers spinning at 7,500, or higher. If you try to increase the rev limit, the pistons are traveling so fast that it would probably self destruct. Hope this helps a bit.

[Zerep]

thats acctually what o needed to clear up. i knew the qr had a really long stroke but i didnt know that made a difference on the the speed of the pistons. so i guess has that bike effect.

[LongBeachCoupe]

I think this is really funny and truly american.... My girlfriend's stepfather is a big republican (i wont even comment) and a big chevy fan and wont drive anything else... with a marlboro red hanging out of his mouth he asked me engine size and then gave me this quote while looking at his old corvette... I guess he thinks that an abacus works better than a calculator too... lol

[cliffy21]

Guys, for reference:

Horsepower= torque X rpm /5252

Therefore, the higher the rpm the engine can go, the more power the engine can output. Car and Driver was just discussing this in the last issue. Higher RPM engines are an easier way to create a higher HP number. Only problem is the the peak power band is so high, you may never hit it.

[Hussain]

what sort of power gains could you get from increasing the displacement on our 3.5se? i know the Nissan frontier has a VQ40. has anyone ever bored out a engine before? any idea on costs? power gains? i'd love to have a 4.0se altima coupe lol