Given To Fly

I have always been really confused about something when it comes to engines, why do many European cars have smaller displacement engines that make equal or more power than American engines that have much more CI. For example, the BMW M3 makes 333 hp out of a 3.2 liter engine (might be a little off on the exact #), where as an LS1 makes about that same amount out of a 5.7 liter engine. Or another one would be the Ferrari F430 that makes roughly 500 hp out of a 4.3 liter engine, where as a Z06 makes 500 out of a 7.0 liter engine!
I know the basic rule for making power: fuel+air+compression+ignition = power, so how are these smaller displacement engines making more power without the aid of turbo or superchargers? Thanks for any info you can give me.

Andros

iTrader: (5)

Dohc > Ohv

ebear

yeah.. but look at the torque to

Engine horsepower 333-hp @ 7,900 rpm
Engine torque 262 lbs.-ft. @ 4,900 rpm


Also look how high it's revved

Weezzer

I think it is because gas costs almost twice there what it does here so they make smaller engines that produce larger amounts of power.

Another reason could be that some European countries charge a vehicle tax that is based on engine size, I know this was common in the 60's & 70's and is probably common today. The larger the engine the larger the fee.

Its one reason several motor cycle dealers developed small engines with multi-cylinders, such as the Benelli six cylinder, and the Honda 350 - 4 cylinder.

It seems the auto makers have followed suit and it has become standard engineering practice.

Another factor is mid and rear engine cars, many of these have smaller engines because there isn't alot of room the way the cars are configured.

Smaller engines also mean easier cooling, especially if your engine isn't located in the front.

jrivera04

Small Displacement DOHC + High RPM = Higher peak power but low torque. Dyno queens love this. 1000HP for 1 second at 9000 RPM
Bigger Displacement DOHC/OHV + Mid to High RPM = More fun across the entire power band.

The Honda S2000 is a prime example of small engine and high revs and its not European. Also, look at the Ford 5.4 DOHC + Supercharger in the Cobras. DOHC lets it breathe better at the top end while the supercharging gives it more grunt on the low end. Perfect marriage of technology.

America is the torque loving nation.
"There is no replacement for displacement"

coldsteelmike

Let's not forget that horsepower = really nothing. You can think of it like this: torque is the AMOUNT of power an engine can output...horsepower is how FAST an engine can output it. Not only that, but horsepower is nothing but a calculatioin derived using torque. Torque is the actual twisting force. It's what actually gets the car moving. ****, I bet you could find a snowmobile engine or some **** with over 200 hp. It wouldn't be able to get a car movin though. No torque. Torque = what you need.

blackbird95

speaking of snowmobiles I've seen people up north put wheels on the front in place of the skis and they run anywhere from a mid 9 to a mid 10

1994Z28Lt1

iTrader: (1)

First of all it takes a certain amount of fuel and air to make 300 hp so a 4 cylinder motor putting out 300 horse and a V8 putting out 300 horse comparing them they will consume about the same amount of fuel with slight differences due more internal friction in a V8

have you ever noticed what european cars such as the m3 and these other imports getting a lot of power through a small motor they dont get very good milage none of them can hold a candle to an m6 LSX car which can easily pull 29-32 mpg loafing around on the highway below 2000 rpm

and as far as cooling its easier to cool a 5.7 litre V8 putting out 300 horse than a 3.2 litre putting out 300 horse because again it takes a certain amount of fuel and air to make that power and making that power will also produce about the same amount of heat with of course differences due to engine design aluminum vs iron and what not

i think more so the reason for smaller engines putting out a lot of power has to do with weight and handling plus the awe factor which also creates the status symbol ( well my little 3.2 litre puts out more power than your 5.7 litre) its all BS

Give me a V8 that gets 28 mph gallon and they can have their little high spinning micro machine that can barely get 25 mpg

ebear

What he said

BigDaddyZ28

Not very likely to see 32mpg out of a LS-1 Camaro... You numbers are even higher than the EPA estimates for our cars and keep in mind that the EPA numbers are estimated on the 'big' side and their tests were done on a closed course.

EPA numbers for the 2002 SS were 19 city, 28 highway (with the optional 6 speed). (EPA info taken from the 2002 SS brochure I got with the car)

Even when my car was new, I never saw close to the EPA estimates as far as mpg is concerned. (Not even while crusing at 2k on the highway)

I think to see 32 MPG you would need a different tune or a different car.


Hope this helped someone out... I was trying.

ls1charged

iTrader: (8)

hell yeah! when i use to live in MI we drag raced snowmobiles on ice, and we were doing 4.5sec.@110mph in 1/8 mile. those things can f$#*ing move. especially the ones that we had.

bowtieman81

iTrader: (35)

This guy is on the right track. It is not difficult to make large HP by revving an engine pretty high, see formula.

hp = Torque (ft-lb) * RPM / 5252

BlueSix

Tell that to everyone that has seen 30+ on the highway.

v8hunter

iTrader: (2)

As many good engine builders will tell you...build a race motor for torque and the horsepower will take care of itself.

I found it funny how when I was a young punk 10+ years ago...one of my best friends had a lt1 z28 and his mom had a stock 140hp honda accord. The z28 got better highway mpg and had twice the power than his moms rice burner. A larger motor doesn't have to work as hard as the smaller one to do the same thing.

Many consider the perfect motor to have equal horsepower and torque ratings for best drivabilty.

The thing I don't like about imports is that you either need to work them hard (rev the **** out of them) to get performance out of them or you have turbo lag to deal with. Not that I woudn't mind driving an sti, m3, or a is350...but that is not what I would prefer.