Engine hp per liter

[Guest Z2nr]

I have a question about domestic motors. Before I do so, know that I am asking out of pure curiosity not insult, I honestly think that the Z06 corvette it the best streetcar I have ever driven. It has great handling, power, torque, and good gas mileage to boot.

 

BUT, the ls1 engine is like 10:1 compression it is a 7.0l engine, why does it only make 405hp to the fly? I have heard people say the design of the engine is state of the art, I find that hard to believe. My 99 Civic Si has 10.2:1 compression and it's 100hp per liter, and it was state of the art back in the late eighties.

 

Why is it that import n/a engine seem to make so much more hp per liter than domestics with similar compression, is it because domestics can't rev and take advantage of bigger cams? I think the ability to rev hinders the domestic motors. I personally like low end torque, but I also love high revving screamers. It's seems that for an engine high revs are the only way to make the engine efficient.

 

Am I totally in left field, can someone help, this is an on going debate between me and a friend of mine and I want to see everyone else’s opinions on the matter.

[johnc]

Do a search. This was discussed at length buy a bunch of folks and no conclusion was reached. Its not a topic that has an obtainable objective result and will become just a mass of opinion with no one's being changed. Most folks already have an opinion and accord greater weight to the folks who reinforce their preference.

 

Basically, HP per liter is just one of many ways of comparing engines and its not intrinsicly better then the others. Racers focus more on power per pound. OEMs focus on power per dollar. Big truck manufacturers focus on power per gallon of fuel burned.

[Pop N Wood]

Plus the LS1 is a 5.7 litre, not 7.0

[Guest ON3GO]

Plus the LS1 is a 5.7 litre, not 7.0

plus the Z06 is a LS6 motor.. sorta the same but not. lol

 

mike

[auxilary]

ah, how you should really ask this question on ClubSi.com's Si vs. All forum...

 

answers:

 

1. Z06 has an LS6 350cid motor, 5.7 liters, not 7. This is now at 71hp/liter

 

2. japan car manufacturers get taxed based on displacement. This is why so many cars are 2 liter or under turbo vehicles, or extremely well engineered car that make crazy power but no torque.

 

3. "if honda made a 6 liter v8, it would make 600hp blah blah". No, this is not true, because if honda did make a v8 making 600hp, it would cost an arm, leg, and a testicle. This is why honda does not produce big engines. Biggest engine they make is a 3.5 liter v6, and most powerful is the 3.2 liter v6 in the NSX

 

4. State of the art? vtec? Ford had variable valve timing back in the 40s. DOHC design? Back in the 20s used in racing. I have a rotary rocket magazine I got from RacerX from 1982 that has an article of a prototype mazda hatchback, awd, WITH variable valve timing, 1.3 liter dohc 16 valve turbo motor. Just because it has high compression it doesn't mean it'll make crazy power. It just means you have to fill up with 91 octane instead of 87.

 

FWIW, my '99 neon r/t is 2 liter, 150hp dohc, 3.94 gearing, and runs as fast as a 160hp civic si. And gets better fuel economy. And has no resale value

 

5. LS1/6 engines are underrated, and undertuned. This is the same reason turbo vehicles from factory make low boost. We all know the L28et can do 10psi without changing anything but adding an intercooler and a manual boost controller and making 60 more hp. My friend's 01 z28 camaro made 440 hp to the wheels with an ls6 hotcam package, and some other tweaks. Naturally aspirated. You won't see a honda making that much power on a b16a2 block.

 

6. While we're at it, let's bust another myth. The chevy smallblock, ranging from the old 4 bolt main 350 from '50s to the all aluminum ls1/2/6 blocks of today, are all (with exception of the LT5, that was a DOHC 32 valve motor) over head valve design with pushrods. Honda crowd always refers to pushrod motors as DINOSAUR motors... When in fact pushrods were introduced some 30 years after overhead cam design was created. Pushrods are simpler design, less moving parts

 

7. In short, hp/liter arguement is good for people who like to punch numbers into a calculator and masturbate to the end result.

[Guest ON3GO]

ah' date=' how you should really ask this question on ClubSi.com's Si vs. All forum...

 

answers:

 

1. Z06 has an LS6 350cid motor, 5.7 liters, not 7. This is now at 71hp/liter

 

[/quote']

its a 346ci if i remember correctly..

 

mike

[Hugh]

Thats why I love turbo. My last motor made 197.5 horsepower per liter at the WHEELS.

[auxilary]

mike: yeah, kind of like the ford 5.0 technically 4.9, and the real 5.0 was the ford inline 6. basic rule is 61cu per liter, and real displacement is 5,665. that puts displacement at 345.565, or 346cid

[Hugh]

3. "if honda made a 6 liter v8' date=' it would make 600hp blah blah". No, this is not true, because if honda did make a v8 making 600hp, it would cost an arm, leg, and a testicle. This is why honda does not produce big engines. Biggest engine they make is a 3.5 liter v6, and most powerful is the 3.2 liter v6 in the NSX

[/quote']

 

 

This is the classic argument, but if you forget about Honda and look at Nissan motors... check out the current Infiniti Q45. Thats a 4.5 liter V8 that makes 340hp and 330 some odd lbs/ft of torque. Still rather small displacement, and yet Hp and Torque numbers are up to snuff. This motor hauls that train from 0-60 in under 6 seconds according to magazine times. Thats pretty damn impressive in my book... even if it is a $45,000 luxury car.

 

I'm not trying to argue about import VS domestic, thats for sure... just pointing out some interesting numbers on Nissan engines that are sometimes overlooked.

[Hugh]

mike: yeah, kind of like the ford 5.0 technically 4.9, and the real 5.0 was the ford inline 6. basic rule is 61cu per liter, and real displacement is 5,665. that puts displacement at 345.565, or 346cid

 

The SR20DET is pretty close to 2.0 liters for real, its 1998cc. Most people look at the engine bay badge and think thats the year of the car.

[Guest ON3GO]

well reason i say what i did was because wasnt the LT1 a real 350ci and the LS1 was 346ci.... shit i know its not much at all of a difference but still..

 

just like you im a ******* alex

 

mike

[auxilary]

yeah, but if we're using the masturbation calculations, then the infiniti is only 2 hp/l ahead of the corvette.

 

On a side note, if Honda was to make efficient v8 motors... why are they going to be making trucks with GM motors at heart?

[Hugh]

I calculate 4hp/liter, but you knew that.

[auxilary]

woops. I must've hit a wrong button when punching it into the calculator

[Hugh]

I figured it was something like that.

 

 

Anyway, the old argument of Japanese companies not being able to make a motor with any real power is right out the window with that Q45 engine, ha? It makes a LOT of power by American V8 standards, or any V8 standards for that matter. I couldn't believe it when I was reading the article way back when the new one was coming out. 340hp NA is no joke, especially from 4.5 liters.

[ZHeadV8]

Auxiliary - great response earlier, thought provoking to say the least !

 

Here in the UK we have LOADS of high powered Japanese cars but very few American style muscle cars (that term is used in the nicest sense of the word) and I think the whole choice thing comes down to how you like a car to drive. Getting crazy BHP from an Impreza turbo or a Mitsubishi EvoVIII is child's play , 5 - 6 - 700BHP no problem but they simply do not have the really low down grunty torque of a big V8.

 

However - the engineering on the Japanese engines is superb and although they CHOOSE not to build an engine like the LS6 I am convinced they could do it with their eyes shut if they wanted to - they evidently don't want to for tax / marketing / image or some other reason.

 

For my money I prefer the growl of a V8 and lots of torque but I guess that's the beauty of all this, we all like and want different things. Looking forward to smokin' some high BHP Japanese cars though

[auxilary]

1bad180sx: I agree. Even in '90, the q45 made 280hp from a 4.5 L v8. Even the LT1 vette that came out in 92 made 5 hp less from a motor 1.2 liters larger in displacement.

 

Everything comes down to pricing: it costs americans a lot less to produce those engines and make a much bigger buck on them in the overall run. When you look at the corvette, for example, it does not have any competition in the pricing department. It is the best car in its class in handling, power, and cost. I mean, what other new car can you buy with warranty for 50k that makes 400hp, runs 12s, pulls 1g on the skidpad, and brakes like crazy?

 

Close competition would be m3, but it's 70hp shy, and doesn't do 12s. Viper? Can do all that and better, but 30k more.

 

In my opinion (and partial fact) the z06 motor is just detuned from factory. It's capable of a lot more, but there's always the warranty issue that's easier for manufacturer to avoid by not stressing the motor as much.

 

One thing I noticed about japanese is that they never invent anything ground breaking: they just do a hell of a job improving and perfecting the existing designs. Piston motors, dohc design, variable valve timing, rotaries... hell I should know, I have one

[johnc]

However - the engineering on the Japanese engines is superb and although they CHOOSE not to build an engine like the LS6 I am convinced they could do it with their eyes shut if they wanted to - they evidently don't want to for tax / marketing / image or some other reason.

 

Well... Nissan/Infinity had a horrible time (and eventually gave up) trying to build a V8 that could compete in the Indy Racing League against the Chevy engines. Honda and Toyota showed up later and put Chevy on the trailer even after Chevy redabged a Cosworth. Toyota had a very difficult time and spent years and hundreds of millions of dollars developing their NASCAR V8 for the Craftsmas truck series.

 

Engine development is not a slam dunk for any manufacturer. Toyota and Lexus 3.0L V6s are getting a pretty bad reputation for blowing head gaskets. Same issue Ford had with their 3.8L V6.

 

Again, this discussion is pointless and no opinions will be changed.

[Pop N Wood]

DOHC design? Back in the 20s used in racing.

 

The 1918 Stutz Bearcats had DOHC, 4 valves per cylinder 4 bangers in a production vehicle.

[auxilary]

toyota v6 motors in 4runners (88-97?) were prone to blow headgaskets after a while. toyota 4 banger motors in camries have been known to have the timing belt slip off teh waterpump and pop off