V8 vs Inline four???

[Michael]

So one has to wonder why all the emphasis on power vs. displacement; why racing organizations group cars based on displacement, why governments tax engines based on displacement (as opposed to, say, horsepower), why bench-racers focus on hp per cubic inch. “It is what it is” certainly summarizes the fact that our little discussion here won’t change the world. But despite that fact, there is merit in discussing whether hp vs. displacement is or is not a relevant measure of efficiency and engineering prowess. I just think that it’s a case of a excessive devotion to a tradition.

[Guest vegeta]

Just to set the record straight, Pparaska:

 

The S2000 will pull a 14.00 sec 1/4 mile time, while the Camaro will pull a 14.00 sec 1/4 mile time. I've seen numbers that are +/- to 14 seconds for BOTH cars (depending on track conditions) so I'd say they were even. Considering the Honda corners a HELL of a lot better than the live-axle, 3450 lb Camaro, I'd say it was faster. No disrespect, it's just the facts.

 

If you look at any issue of Consumer Reports, where they compile information on just about every make and model car in the last 10 years, you will find that the facts show Japanese manufactured cars last longer, and have fewer problems than ANY OTHER MANUFACTURERS cars. The European brands are high to low average, and the American brands were the bottom of the list. FACT.

 

As far as power is concerned, we know hp is just torque times rpm divided by 5252, and that hp is the rate at which a vehicles mass can be accellerated. So you can make hp with torque or rpm. Jap cars tend to use high rpm to make power, while U.S. cars turn less rpm, but make more torque in order to make hp. But everyone always quote PEAK hp, which is not an accurate measure. As it was stated earlier, it's the AREA UNDER THE HP CURVE that determines accelleration, as well as the weight of the vehicle. The area under the curve would tell you how much hp through the entire range an engine makes. So with equal gearing, if 2 cars made equal PEAK hp, with equal vehicle weight, equal traction, etc, the car with more AREA UNDER THE CURVE would win. At any given rpm, say 3000 rpm, whichever car had the most hp would be faster for that instant, so if you have more average hp across the rpms, in equal conditions, you would be faster. So one might assume that since a higher displacement engine (like the 350 sbc in an 80's corvette) making 240 hp at around 4000 rpm would be better than the S2000 engine's 240 hp at 8500 rpm, because the bigger engine is making more torque and therefore more power across its range, one might forget the fact that the vette engine redlines at 6000, while the S2000 engine goes on to 9000. So the S2000 might have as much AREA under the curve as the vette (area meaning length times width, so if you think of a dyno chart of engine hp being a graph of the area, in this case length is the rpm length on the dyno chart, and width is the hp at each rpm on the dyno chart) because although the honda doesn't make as much hp at each rpm (width) as the vette, it makes its hp across a longer rpm band (length). Plus, since the S2000 turns 1.5 times as many rpms as the vette, it can be geared 1.5 times higher, and still have the same speed in each gear as the vette. This means 1.5 times power output. Anyhow, that's just an example, and I KNOW ITS A BAD EXAMPLE, because any SBC can make well over 400 peak hp, but I just needed to show large displacement, low rpm versus small displacement, high rpm, and that example came to mind.

ANY engine, regardless of make, type, or what have you, will make more power if you either A)increase displacement, or B)increase rpm. Or both!!!! Like NASCAR's Winston Cup 5.8 liter v8s that turn 9000 rpm and make close to 900 hp!!!!!! The thing is, since those engines are old-school pushrod v8s with lots of rotating mass etc, they need to be rebuilt frequently because they can't handle the stress of 9000 rpm nearly as well as the Honda STREET CARS that regularly hit 9000 and run to 200,000 +miles on the odometer.

 

Anyways, there are a lot of very intelligent people on this forum with very interesting posts. I'm not saying Japanese engines are better or worse than American engines for performance, because a big v8 is nothing to mess with. But we have to look at facts before we make judgements.

[Guest vegeta]

By the way, if we were talking about pure Horsepower Per Dollar, its almost impossible to match a SBC. Why do you think so many people put v8's in Zs?

[baddriver]

"By the way, if we were talking about pure Horsepower Per Dollar, its almost impossible to match a SBC. Why do you think so many people put v8's in Zs?"

 

That really sums it up, in my opinion. Go to the junkyard and tell them you need a 250 hp engine for $400. You'll get a chevy, or at least a V8. Yes, you can get more HP with less weight. But more with less money? I haven't seen it.

[David K]

Honda has better engineers then General Motors. GM is even buying Honda V6 engines to put in future Saturns

 

Thats the most ridiculous thing ive ever heard...I hope it was meant as a joke.

 

If you built that 5.7liter motor to the same specs as the S2000 motor (9000RPM redline, higher compression, etc)...it would probably eclipse 8 or 900 horsepower.

 

Thank you for making Johns point even clearer.

[pparaska]

ANY engine, regardless of make, type, or what have you, will make more power if you either A)increase displacement, or B)increase rpm. Or both!!!! Like NASCAR's Winston Cup 5.8 liter v8s that turn 9000 rpm and make close to 900 hp!!!!!! The thing is, since those engines are old-school pushrod v8s with lots of rotating mass etc, they need to be rebuilt frequently because they can't handle the stress of 9000 rpm nearly as well as the Honda STREET CARS that regularly hit 9000 and run to 200,000 +miles on the odometer.

 

I seriously doubt that if any Honda STREET CAR is revved to the 9000 rpm range very often, and kept there long enough to make it accelerate well, that it would last 200,000 +miles.

 

BTW, The S2000 was just redesigned due to too many complaints of it's power band being too high in the rpm band.

[SleeperZ]

"By the way' date=' if we were talking about pure Horsepower Per Dollar, its almost impossible to match a SBC. Why do you think so many people put v8's in Zs?"

 

That really sums it up, in my opinion. Go to the junkyard and tell them you need a 250 hp engine for $400. You'll get a chevy, or at least a V8. Yes, you can get more HP with less weight. But more with less money? I haven't seen it.[/quote']

 

Unless it's an L28ET for $200. Stock you can make 300hp.

[johnc]

I seriously doubt that if any Honda STREET CAR is revved to the 9000 rpm range very often, and kept there long enough to make it accelerate well, that it would last 200,000 +miles.

 

As of early September, Bob Endicott's 2001 SCCA T1 S2K has over 100K miles and it competed nationally road racing for 18 months and his wife has been driving it on the street and autocrossing the car. As far as I know the engine's never been apart.

[Guest vegeta]

Pparraska,

I was trying to point out that the Winston Cup engines that push 9000 RPM with the old fashioned pushrod, carburated design need to be rebuilt after EVERY RACE. Granted, those race engines never see below 5000 RPM, but anyone who has ever driven an S2000 knows the tach has to be burried near redline all the time to maintain speed. Obviously the thousands of S2000's that see daily street duty are not being rebuilt all the time. No hard feelings, just my 2 cents

[Guest vegeta]

...I hope I didn't sound like I was trying to talk down on American Iron- I LOVE a good V8. I was just speaking in terms of modern cars' reliability.

[Guest Smooth Operator]

Pparraska' date='

Obviously the thousands of S2000's that see daily street duty are not being rebuilt all the time. No hard feelings, just my 2 cents [/quote']

 

Well they're fairly new. I'm interested to see how they hold out over te next 10 years or so.

[Guest 81na ZX]

A quick overview: intake air comes rushing in at ~the speed of the piston, valve closes, air 'bounces' off the back of the valve and this negative (because of direction only) wave propigates back into the intake. It bounces around in there, and then comes back down the runner again at some point. If you time the intake to be open when the positive wave propigates back down to the valve back, you get extra air forced in by the wave, if you are a split second too late, the wave has bounced back (negative), and instead it pulls air away from the valve, lowering VE.

 

Old thread, but....

 

There are two main theories that pertain to manifold tuning and allow the formulation of geometry that should lead to improved volumetric efficiency. One holds that a plenum- runner manifold combines the effects of a quarter-wave organ pipe and a Helmholtz resonator and that each can operate either independently or in conjunction as a "system." The other contemplates "wave motion" within the manifold, varying as a function of rpm, piston displacement and a host of related variables.

 

Using the helmholtz resonator theory, you can design the lengths of intake runners to utalize these waves to your advantage. What ends up happening is that when the valve closes, the intake hits the back of the valve and reflects back. Using the duration of the cam, and a guess at the pressure wave speed (1250-1400 fps), you can find the exact length of runners so that the valve opens the exact time the refelcted wave has hit that location (or the 2nd time its back, or the 3rd time, or the 4th time, etc.). You need these subsequent waves, because in a theoretical 5,000RPM engine with 30mm runners, the runner would need to be a 39.6mm long to catch the first wave. But only 12.3mm to catch the 2nd wave.

 

 

max RPM is realated to piston speed and valve train speeds. Piston speeds are measured in feet per minute, with 4500fpm a good limit for most OEM components. if bore is given in mm, piston speed = (Stroke * RPM) / 152. Thus, a RB20 (stock 69.7 stroke) can, by piston speed, spin to almost 10,000 RPM. Piston Speed @ 10k = 4585fpm. However, I don't think the valvetrain can take that...

[cameraobsess]

hey i liked what moridin2004 said, not all four bangers are the same. you can find some that make nice power. dont get me wrong im a big engine kinda guy but i dont dis the little guys to much. my good friend is obsessed with his ford focus and well i still try to convince him of the folly of his ways i have to admit it has some nice low end power. takes off fast. he hasnt done much to it ither. i still say my car could beat it even with the tranny problems im having but its a nice powerful paper weight.

as for them being lighter, well yea they would be lighter most of the time. they are four bangers not six or eight or ten or twelve but if you get a big enough four its going to be heaver than a small eight. i have seen lots of guys on here with 302 fords that weigh less than the l6. funny that.

[Guest penguin]

i just wanted to say a few things, i know this thread is old, so ill make it short.

 

i believe nascar is limited to 500cid, not 5.0l, so thats really 8.2L

 

yes, japanese cars have a history of lasting longer. but thats the 65hp/L toyota camry, not the 120hp/L s2000. i dont care if so and so from east lower hoboken has one that has run for 1,000,000 miles, he has had to invest more than the price of the car to keep it running the long.

 

an s2000 is a high tune engine. high tune engines arent cheap. arent cheap to fix. and boy howdy do they break. when was the last time you heard people gushing about the reliability of thier ferrari 360? it gets more than 100hp/L. it breaks, and high strenght, low tolerence parts arent cheap.

 

and as far as honda engineers being better, i see no new idea coming out of them. they sure toot thier own horn about the precision of the insight with its electrics and range. ferdinand porsche built a totally electric car in 1908, when he was 18.

 

honda just has better commericals.

[Guest vegeta]

penguin,

 

First of all, Nascar's Winston Cup (which will be called the Nextel Cup next year from what I hear) cars engine displacement is limited to 358 CI, which is 5.8 liters. Look it up

And just because old Ferdinand had an electric car in 1908, it doesn't justify the big three's (Ford, GM, Chrysler) incredibly neanderthal engineering in 2003. Honda came out with variable valve timing technology and offered it at very affordable prices LONG before any Detroit manufacturer even thought about it. That's better engineering, or maybe just better business practices (offering better products at affordable prices). And Honda has continued to evolve that technology even further over the years, offering cars with higher output per displacement, while still being fuel efficient and driveable at lower RPM. Did you know they can vary the duration of both intake and exhaust cams INFINITELY at any rpm? And there is a SECOND SET of cam profiles (for each of the FOUR valves per cylinder) that provide more lift at higher rpms? The few American cars offered with variable cam technology aren't as sophisticated. And there are far less U.S. built cars with this tech. Add to that the far greater reliability of Japanese manufactured cars and you see why someone might have the oppinion that Honda has better engineers than (insert U.S. manufacturer name here).

Don't get me wrong, I had two Camaros and they were fun, and my dad's 1965 Stingray was VERY nice

But these days the domestics just can't compete with Japan as far as reliability. Honda S2000 included.

[cameraobsess]

you know i doubt anyone was really dissing any of the companys. why do we keep trying to stick up for them like someone is blatently dissing them. we all have diffrent views on what we like and what we dont. personaly i like the less complex engines. i think that when we make something more complex than it needs to be its just asking for problems. im not saying that high tec is bad, but sometimes they go overboard on new engines just to make them look good. i would rather have a time tested and proven v-8 than a new "high tec" four. Eventualy these new techs will be proven. when they are i wouldnt be supprised to see some V-8s with them. it might not be the people designing the engines who are holding the designs back but more the companies unwillingness to except change. the market for the Japanese cars requires them to be more willing to change so that their product is diffrent than the american cars. im not saying that any one company is the better for it but they both still sell cars, go figure they are doing something right.

[Guest vegeta]

I agree with alot of what cameraobsess said

 

But as far as the new techs being "proven" I think 15 years of production and great reliability is pretty solid proof.

 

The high tech/low tech thing has alot to do with where the cars are being sold. The price of gasoline in the U.S. is WAY cheaper than 99% of other countries in the world, so it would make sense that there is less of an emphasis on efficiency in U.S. Domestic cars. (assuming that efficiency= higher tech). This explains why many European V8s have quad cams and vtec, like BMW, AUDI, etc. because gas is like $4 a LITER!!! (they sell it in liters, not gallons ) The Japanese car makers also have to deal with this, as well as strict emissions laws, and so all their products reflect this, even cars made for the U.S. market, because this is what we expect from them.

[cameraobsess]

i agree that gas prices have a lot to do with it, but thats not all there is to it. if you look at europe the car to family rartio is less than america (england is close but its not the same) for the most part the car is still a symbol over there. and the richer you are the biger the car and engine are. cars here follow a simaler rule just everything is already big. it just gets bigger. when you are dealing with people who want a symbol of their wealth you want to give them new gysmos things that sound good and look expensive. people want to show off and it shows in how the cars are built.

[Guest vegeta]

Yeah, that's true. It's why everyone wants an SUV these days instead of a minivan. Bigger, cooler, etc

[cameraobsess]

exactly, but it effects how the companies design their cars. here in america it would be bad for sales of some cars to say new high tech engine is more fule efficent. the selling point on the car is that it guzzles gass. it has a statment. "i can afford to fill this tank all the time". there are exceptions but for the most part it would be bad for sales to do to go to far right now. plus Bush dosnt want us to go efficent. his administration is based around keeping our economy tied closly to oil. im not talking about the iraq war. more about his constent search for oil. alaska is a prime example. plush he changed the government funded research on clean cars from what clinton had. no offense to ither president but clinton got us results when it came to efficentcy. politics plays a role in car development as well as all the other things we have already talked about.