V8 vs Inline four???

[datsunlover]

Funny.. I was talking to a friend tonite about engines.. got to thinking about the original Z 2.4 engine.. 150Hp from a fairly small 6cly.. and that was in 1970! Someone correct me if Im wrong (which I probly am..) but in 1970, a domestic V8 didnt make that much more Hp even though it was 2 X the size... At this point, the original Z L24/26/28 isn't anything special to look at, but it seams to me it could be considered quite the 'enginering marvel' 30 years ago. And on the 'reliability/longevity' issue.. I'v never heard of a 15 year old SBC (my L28 was rebuilt in 1980) that still runs well...

[pparaska]

Like I said before, i'm not bashing V8 iron. I'm probably going to put one in my Z. It just seems like a lot of the people who are into traditional domestic hot rodding aren't really aware of the performance you can get from high tech, high revving engines.

 

Yeah, us old hot rodders are really ignorant about high tech engines. We don't realize that you can rev 4 cylinder and make lots of power - WRONG.

My daily driver is a 92 Eclipse GSX. Fun. But I'd give up the finicky power of that engine for 250 all the time, NA hp in a heart beat. If the chambers get a bit of oil burnt in them (PCV valve) or it's a bit warm out the power falls off.

 

Plus, I like to cause a ruckus now and then

 

Why? You mean you like to piss people off, just for the heck of it?

Personally, I don't need that kind of BS in my life.

[pparaska]

Phantom' date='

Give me a break. There's nothing high tech about an LS1. It's the same pushrod engine they've been making for years, only with nice EFI. Don't get me wrong, its a good engine, but its not high tech.[/quote']

 

It's not? Hmm. I bet there are alot of GM engineers that could educate you on just how high tech it is. But you seem to have an issue with pushrods... The LS1 does exactly what the designers wanted it to do - make electric motor torque from below 1500 rpm to 6500 rpm. They knew that no one would want a Vette with a 4000-8000 rpm powerband. And they designed and engine with a very sophisticated combustion chamber, port designs, ECU, intake, exhaust, bottom end, to do the job. But yeah, those pushrods - such a mistake. NOT.

 

And parts for an LS1 are MUCH more expensive than any other SBC, and no cheaper than any parts for the L-series engines.

 

I'll wait for Mikelly to straighten that out for us. Just wondering, are there any aftermarket manufacturers of the repute of AFR that make cylinder heads for the Honda engine? Toyota? That are affordable?

http://www.strokerkits.com/afr_lsi.htm

 

Of course if the valve train is a pushrod design, it will be under WAY more load at 8000 rpm than an OHC design. Pushrod engines don't safely rev that high.

 

Ever watch any NASCAR? Sure, they won't from the factory, but they don't NEED to. But that doesn't mean pushrods are some kind of square wheel or something.

 

And you said that an american engine, when equivelantly designed, will last as long as other makes. But thats the point. They ARENT equivelantly designed. Most stock domestic engines have cast internals that are externally balanced, controlled by unreliable electronics, and have a neanderthal valvetrain.

 

Do I smell bias? Unreliable electronics? Neanderthal valvetrain? These are generalizations. They have no basis in fact. They only show you're reaching for straws... Cast internals - nothing wrong with that if it's all that's needed...

 

Contrast that with the average euro or jap engine and its a drastic difference: mostly forged, internally balanced rotating assemblies, with durable electronics, and ohc, sometimes VVTI, etc. valvetrains.

 

I bow down to the superior engineering. NOT Give ME a break vegeta. If you HAVE to turn rpms, use small journals since everything is about light weight, etc, you do get FORCED to use forged parts. That doesn't mean it's "a better design" - just a good design for the intended use - a very efficient high revving engine that's 2 liters or less.

 

Even in '75 the Z had forged steel crank, forged steel rods, OHC, EFI, and internally balanced.

 

In 1962, the Chevy 327 had a forged crank, forged rods, some had forged pistons. Internally balanced too. Some had fuel injection. OHC would have made the engine huge, and it WASN'T NEEDED - it made 360hp@6000rpm, 352 lbft@400rpm without it:

http://www.theautochannel.com/vehicles/muscle/corvette/62vette.frame

 

 

The average Nissan, Toyota, Mazda, BMW, etc today have these features. And the japanese cars with all of these high tech impliments sell for the same as the domestic equivelant. And last longer. Seriously, have you seen any reliability ratings lately?

 

Yes, I have. And just about all the cars out there a highly reliable, no matter where they come from.

 

But like I said, although they still dominate the SUV segment, Detroit has noticed the car market in America slipping to foreign companies, and they are responding very well with some great products on the way. Ford's Mustang has been pretty good when it comes to updating: even though the base model still has a live axle (as opposed to an IRS) the base v8 engine is a nice, aluminum, SOHC engine, and the Cobra has had a DOHC engine and IRS for a while now (might have something to do with the death of the Camaro). GMC has a very nice L6, DOHC, VVTI engine in the small SUVs that they sell, too. And the Cadillac Northstar engine is impressive with all of its features (dohc, vvti, etc). Chevy is about to release the Cobalt, which is basically a honda civic clone, but thats a hell of a lot better than the old cavaliers that it replaces. And Dodge has the SRT4, which has a badass turbocharged, dohc 4 banger, and even though it only costs around $20k, it is as fast as the last SS Camaro (which cost around $30k). The list goes on....SVT Focus, Saturn Ion Redline, Pontiac Solstice, etc. So the domestics have obviously noticed what's really going on and have responded. But it took a decade and a half of superior imports to provoke them.

 

Yep, they were for the most part asleep at the wheel. But over-generalizing will not sway me.

[wheelman]

Datsunlover,

 

When you say that the V8s of 1970 made little more power than the l24 in the 240Z I think you are actually refering to the smog era engines of the mid to late 70s. Those engines were so choked with emissions things they could hardly run let alone make HP. All engines had those problems. If you look at the stock power output of the Z motors the 1970-1971 240 had the most HP of all. Datsun was forced to increase the displacement to allow the motors to pass smog and make HP.

 

As for old tech VS new tech / low VS high we need to take a hard look at this arguement. The basic design of the internal combustion engine hasn't really changed since the first were built and all the "High Tech Innovations" attributed to "imports" had been tried in the dark past, except for electronic controls. So our engines are all relatively low tech compared to advances in other areas of science and engineering.

 

As for qualilty of imports VS domestic. There used to be a real difference but now that the domestic companies have had to compete with the imports for long enough their quality has increased dramatically. My impression is that most of the guys argueing the imports are better want to compare 80s era engines. Not a fair comparison. But compare a 90s era import to an LT1 or a Ford 5.0L and they compare very well as far as reliability. Most of the problems I've had with the newer cars weren't mechanical but electronic and all makes suffer equally with quality problems there.

 

Wheelman

[Guest 81na ZX]

I'll wait for Mikelly to straighten that out for us. Just wondering' date=' are there any aftermarket manufacturers of the repute of AFR that make cylinder heads for the Honda engine? Toyota? That are affordable?

http://www.strokerkits.com/afr_lsi.htm

[/quote']

 

Quality vs. quality I don't know about, but Dart makes Honda heads and blocks now.

[Guest vegeta]

Pparaska,

 

Hey man, don't get so upset. I wasn't trying to "piss you off", what I meant by "ruckus" was an interesting debate, not a shouting match. I have no cruel intentions, only my oppinions. Just relax . Besides, I didn't say domestic cars sucked, I just said they havn't been as reliably built as other makes in the last 15 years. Consumer Reports recently put out a list of manufacturers in order of reliability, and the top of the list was Toyota, followed by Honda, Nissan and the other Japanese makes, and then the European makes made up the middle of the list, with the domestic makes at the bottom. Turns out my statements ARE based on facts. Just go read Consumer Reports, honestly, they've been around for a long time and are respected for offering an unbiased, well supported evaluation of all kinds of products, especially cars. You can see that the domestic cars received much worse scores than other makes in reliability, especially electronics (ECU, etc).

 

In the days of muscle cars the domestics kicked ass. And I still like those cars. But the newer Detroit cars aren't as good, comparitive with other makes, as they once were. I was just trying to explain why. This doesn't mean I have a bias. I have only owned five cars, but three of them were fairly modern domestics (thunderbird and two camaros) and I didn't enjoy paying for all the gas they guzzled relative to their crappy performance, and all the repairs I made to them. My Z solved all these problems. Don't you just LOVE the Z? When comparing the '62 vette to the '75 Z, the vette did have fuel injection, but that was MECHANICAL injection, and it was a MUCH more expensive car. Back then the vette was pretty reliable, relative to the competition, but that changed in the mid '70s, and vettes havn't really caught up in terms of reliability. But they are awesome cars in terms of performance, no doubt. My dad had a '65 and now has an '88 (which blew a head gasket at only 80,000 miles ).

 

Anyways, the LS1 is not very sophisticated. All of the engineering time they spent trying to find efficient port design with the two valve heads could have been solved by adding two more valves to the chamber. With a 4 valve chamber, you get a 15% increase in valve area = more power, more efficient burn, etc. And 15% is an increase that most engineers would kill for. Even adding variable cam technology would be a HUGE improvement, because the computer can vary the duration and lift at any given rpm. I hear guys debating for hours about what cam is best for their old school v8, weighing the tradeoffs between smooth idle and top end power, and the tradeoffs between more lift and passing smog, but with the VVT you can just tune the ECU and there will be no tradeoffs. DOHC does not make an engine huge, either. Go look at a Northstar, they're pretty compact.

 

As for high rpm, I don't think anyone would say that a Nascar engine would be good for more than a few races at most, its not like they're streetable, not to mention the valve train is signifigantly different than your average SBC, SBF, etc. ANY speed shop mechanic will tell you that you don't want to rev a pushrod engine very high for any amount of time unless you plan on rebuilding. The rules in Nascar prohibit the use of any kind of technology that came out after the '50s. They force the teams to use pushrod, carbureated engines coupled to a four speed trans and a live axle rear suspension. And although that is very cool for nostalgic purposes, its not nearly as good as it could be, which is why 99% of racing series allow for better technology in the cars. When Chevy really wants to rev their engines, such as in the IRL series, they use a Northstar/Aurora based DOHC vvti V8 engine.

 

The way I see it, Chevy keeping the old SBC design in the vette, and Dodge bringing back the Hemi, etc, is a way to make sales to the die hard fans by retaining their desired nostalgic image. It's EXACTLY why Porsche sold the 911 with an air cooled engine for so long (until around 1997, I think). The die hard Porshe fans were hell bent on their belief that air cooled was better, and when the 944 and 928 came out with water cooled engines, the fans freaked out, and those models were eventually discontinued. So the 911 went on with air cooling, but eventually Porsche had to move on because they knew a water cooled design is better. Why do you think there aren't many (any?) air cooled engines made today?

 

Aside from reliability, if you're just talking performance, I agree with you that if you want more power you can just make the engine bigger, which is what they do. And I have nothing against hot rodding with old school iron. In fact I think its frickin great. But in a modern everyday car, making the engine bigger instead of making it better is just lazy. If you just decide to make it bigger, without improving the design, then you get the required power, but you get worse mileage and worse emissions, and worse reliability. Remember, I'm not putting down the old v8 in anyone's Z, that's cool because its a fun toy thats fast as hell and was never intended to get good mileage or have any modern electronic conveniences that might break, it's a different scenario and I support it. I'm talking about the average Detroit car these days. And I'm not some idiot ricer either, I don't confine my interests to any one narrow type of car. I like them all, as long as they're fast and badass.

 

This is a great thread. I like hearing everyone's thoughts, and like I said, I'm only trying to encourage healthy discussion.

[Guest vegeta]

Wait, I just remembered this thread started as "V8 vs I4", and I'm not necessarily arguing that exact point. Maybe that will clear something up?

Later

[Pop N Wood]

I hear guys debating for hours about what cam is best for their old school v8' date=' weighing the tradeoffs between smooth idle and top end power, and the tradeoffs between more lift and passing smog, but with the VVT you can just tune the ECU and there will be no tradeoffs.

[/quote']

 

No tradeoffs? Are you serious? So there is no reason to ever put an aftermarket cam in a Honda? One could argue whether the average Honda owner is knowledgeable enough to upgrade a cam, let alone know how they work.

 

The way I see it' date=' Chevy keeping the old SBC design in the vette, and Dodge bringing back the Hemi, etc, is a way to make sales to the die hard fans by retaining their desired nostalgic image.

[/quote']

 

You just answered your own question on why the Japanese are so enamored with DOHC. Marketing. Make people think what you have is better.

 

DOHC, 4 valve per cylinder inline 4 engines have been present in production engines for almost 100 years now. What the hell is high tech about that?

[Phantom]

Engines are built for specific services. By definition

America engines tend to be larger and designed for lower end torque for several reasons:

1) Our cars are generally larger & heavier,

2) Our people are generally larger & heavier

3) Our roads are designed for long distnace relatively high speed driving (no Autobahn arguments here please) by the masses rather than the rich elite, and

4) Americans have been spoiled by relatively powerfu, quiet automobiles.

Please note that I am talking in generalities here - there will alwasy be exceptions.

If you look at foreign cars you will notice an interesting trend. They came to this country with engines in the 1.3-1.8 liter size I4. Now they are up to a 5.6 liter V8 from Japan (Please note all the Japanese Luxury cars are over 3 liters now) and the Germans are up to 6 liters & V-12's.

The high technology in the heads was induced again by need, not desire. The global economy has forced - especially in Japan - the development of small I4's. Just look at the taxes they pay for something larger than 2.0L!! Like any other enthusiasst they too like powerful engines so they focused on the smaller engines to try to provide something to their local market that would perform similarly to the american cars which were able to get the same HP by just going up in displacement. Fuel economy was not a major issue here (we may complain about the cost of fuel but how many guys on this forum are designing their cars for better fuel economy?) and the V-8 provided excellent low end torque (especially the 2-valve designs) and HP for daily driving in the larger sedans and SUV's that dominate the market. Remember the battle cry - "There is no replacement for dispacement!" It still holds true when talking apples to apples.

Has anyone read up on the new Cadillac V-12? 750 HP and over 20 mpg. Variable valve timing, 3 or 4 valves per cylinder, dual overhead cams, rev's to like 9,000 RPM. I think it is due for production in 2005 or 2006.

I postulated for 5 years about what I was going to put in my car and then opted for the LS1. I wanted an engine with readily available parts, significantly upgraded technology over the L28 and I wanted the day-to-day reliability I would get from a "stock" motor versus a hopped up I6. I've driven the L28 for 18 years now, it's a great engine but it is really long in the tooth design-wise. My co-workers 1967 Mercedes SL280 has the same basic engine but with mechanical injection - 40 year old technology! And the LS1 isn't higher technology?

[Savage42]

Alright, there is definitely a difference of opinion and different experiences or preferences. Here's my 46 cents.

 

First, I started with my '71 Datsun 510, which came with an L-16 SSS motor, which had flat-top pistons, peanut head, cam, & dual SUs. It was fast enough to keep up with my buddy's 240Z (w/ L24). That wasn't enough, so I built a .080 over L18 w/ flat-tops, bumping up the HP & torque a bit. I was probably at a whopping 150 HP, but this was a decade ago & was my daily driver. It also got close to 30 mpg hwy. Then I stepped up and built and L22 (stroked L20B) 4 cylinder, headwork, cam, dual Mikunis. I had about $3k into the long block, then got rid of the Mikunis and went with the TWM/Electromotive EFI/direct ignition setup, another $3k. This was good for about 200 HP and was pretty good for my 2100 lbs 510.

 

When that wasn't enough, I could either spend a ton of money supercharging the 4 banger or go a different route entirely. I then went with a VG30 turbo (3 liter V6) that put out 340 HP / 400 ft lbs. That was fun for a couple years and the larger displacement and added torque made it much more driveable than the 4 cylinder motors. I've ridden in SR20DET 510s with virtually the same HP numbers at the wheels, but they are totally different beasts. It was the torque of the V6 that made my car so much nicer to drive than constantly working the shifter and revving to 7500 rpm like the SR20DET. I sold the 510 and am now building the V8 Z, due to the fact that you can only get a brick of a 510 to go so fast due to aerodynamics and I couldn't fit much more motor in there. Also, turbo cars also tend to get fairly crappy gas mileage, as it takes more revs & boost to get power, where a V8 car works down low with less pedal.

 

Even though I'd never own a car with less than a V6, I have nothing against these high tech import motors. The Japanese are the kings of getting monster power from small displacement motors, due to the fact that they are limited in displacement due to regulations & taxes in Japan. It's obvious that the domestic guys have the V8 thing down pretty well. You'd be hard pressed to get any 4 cylinder motor to get 400HP/400 ft lbs, excellent driveability and nearly 30 mpg. Torque is king and only those who have had it know what I mean. Those who haven't......well, they don't have a clue.

 

It's obvious that times are changing and these hot import cars are the modern day "muscle cars". Different strokes....... I just laugh at these guys who spend $30k on a Honda (grocery-getter) and $10k of "go-fast" parts on it and get spanked by a 10 year old (or less) Vette for half the price. Personal taste, performance goals, the process of simply building your own car are all things we have the luxury of doing, although "taste" and ways of going about it are going to cover the entire spectrum.

 

Bottom line: I think the only valid opinions comparing the different motors, etc would come from people who have owned & driven all of them. Some guy talking "theory" and giving their "opinion" means nothing to me and the rest who have "been there, done that". Like they say: "Opinions are like.......". I once heard someone say "size does matter" and I'd have to agree. hehe

[johnc]

I think the only valid opinions

 

Valid Opinion is an oxymoron...

[Savage42]

Just like:

 

Postal Service

Military Intelligence

Country Music

 

Ah, you get the point.

[Phantom]

I think Jay Leno has the right idea. He has a hot rod with a Sherman Tank engine. 810 HP and 1276 lb-ft. of torque!!

[Guest vegeta]

Once again, I'm not really arguing the original point of this post, but....

 

Savage42,

I don't know if you were directing your comments at me or not, but like I said, I have owned a few "bigger" american cars (t-bird and two camaros), as well as a couple imports (prelude and 280Z), and I was a valet for a year up in Napa County (where folks have lots and lots of money ) and I got to test drive all kinds of cars (believe me, "Farris Bueler's Day Off" was not lying about valets ) I drove a ferrari 360, F355's, a 348, porsche 911's, a turbo 911, 928's, boxster's, old and new corvettes, supras, bmw M3's, M5's, roadsters, mustang/cobra's, a 3000gt, a couple 300zxtt's, an S2000, an rx7 tt, integra type-R's, a celica gts, a hopped up old nova, a chevelle, a new camaro ss, a late model impala ss, an svt focus, and every plain-jane car in between. I even drove a newer Rolls Royce convertible owned by this guy who looked like a Sultan. So I have first hand experience (been there, done that) with this subject, maybe not 20 years worth like some of the guys on HybridZ, but definitely enough to know the difference. Not to mention that I have worked on plenty of cars of different makes throughout my automotive training at COM/ROP. I would never say I have all the answers, but I always try to back up my oppinions with facts.

And just to set the record straight: I DO BOW DOWN TO THE WISDOM OF THE HYBRIDZ GURUS.

 

Responding to what you said, though, $30,000 gets you way more than a grocerie getter, hell, you could get a new 350Z or a Lancer EVO VIII or an RX8 or a WRX STI or an S2000, all badass machines capable of matching and/or beating a 10 year old vette, in STOCK form. If you don't believe me, you can grab a back issue of your favorite car mag, and a new issue, and compare performance of these cars. In fact, the STOCK EvolutionVIII and WRX STI match the performance of a NEW vette. And they do this with 4 cylinder engines (there, that relates to the original post ). Plus, they are 4 door sport-SEDANS that get better overall gas mileage, have 4 wheel drive, nicer interiors, and are cheaper

 

And anyone who spent 10,000 bucks in performance parts on their honda that isn't getting at least high 11's in the quarter mile is obviously doing something wrong. I've seen many turbo H22 Honda CRX's at the strip that are at least that fast (it makes sense: 1800 lbs, 300+ hp). And turbo cars actually tend to get better MPG than an N/A car of equivelant HP (thats why there was a boom in turbo performance cars in the gas-starved 80's). I do appreciate hearing your perspective, though, because you've had lots of experience with different cars and are willing to share your ideas with me, so I'll try to be open minded.

 

Pop 'n Wood (awsome name by the way ),

Most tuners of Honda B-series engines don't need anything more than the stock type-R cams (civic type-R, integra type-R). They already come with mild enough low end lift, and very aggressive lift on the second lobe profile. The rpm at which the second lobes kick in, as well as the duration of the cams at any rpm, is controlled by the computer, and therefore tuneable. Also remember that Honda is not the only company from Japan, and not the only company with this technology. My whole point was that any of these high tech engines are very cool because you can VARY the lift and duration as you please, so you can get killer power in your power band, and still be docile, smooth, and clean at the lower end. Since you get the perfect duration for each incremental RPM, you don't sacrifice low end driveability for high end power, etc. There are many aftermarket companies producing these computers. Its all basically plug-and-play type stuff, so you can bring your laptop to the track with you and tune your engine on the fly- with no wrenches even! THATS whats so high tech about DOHC, the possibility of more sophisticated valve control. If there were pushrod (OHV) engines with any kind of VVT, that would be high tech, too, except there would be no seperate control of intake/exhaust valves, as there is only one cam to control them all, and you would be hard pressed to fit 32 cam lobes for VVT on a pushrod type single cam anyways.

 

DOHC is not just a marketing gimmick. Do the math. In any combustion chamber, you can fit four slightly smaller valves that will have more total circumferance (= more flow) than if there were two large valves in the same space. And the inherent crossflow, hemispherical, central spark plug nature of the four valve chamber is an added bonus. If it were not a better design, then it would not dominate most forms of racing (excluding series like Nascar, where the rules prohibit it), because the teams design engines to WIN, not because they bought into some marketing ploy. That's also why in some forms of racing, such as classic car or showroom stock, where some cars are OHV, and some are OHC, the less sophisticated OHV designs are sometimes allowed to have more displacement than the OHC engines, just to keep things competitive. Even in American LeMans, when the C5R Vettes weren't doing so well with the "small" displacement of the LS1/LS6 engine, they changed the rules to allow 7.0 liter vettes. The Ferrari 550's that were powered by 5.5 liter v12's were just as fast in that series last year with much less displacement. There's more involved in that story though, like the Ferrari team being a small budget, private team as opposed to the Vette and Viper being factory backed teams, I could go deeper into that but I won't.

 

My oppinion is its just such a waste to have all that clanking machinery (16 lifters, 16 pushrods, 16 rocker arms) in the valvetrain of OHV (pushrod) engines, just to get the valves to open. It's unnessecary. Even in a two valve per cylinder design, if the cam is on top of the valvesprings theres much less reciprocating weight, less frictional losses, and much less flex in the valvetrain, which results in smoother operation, higher rpm capability, and quicker translation of the "ramping" of the cam-lift to the actual valve. This is why Ford made the "modular V8" in their newer cars. Even though they are only 2 valve per cylinder, they are SOHC, and high performance variants use the 4 valve/DOHC heads. In fact, I'd say that Ford is probably the most progressive of the domestics, next to Cadillac (Man, my Bowtie buddies are gonna kill me for that one ) If you look at all the V8's from over seas you'll see that they are all OHC, mostly DOHC, sometimes with VVT.

 

I understand why an oldschool V8 is so apealing for a hotrod project, its VERY powerful, compact for its displacement, simple to work on, and parts are cheap and widely available. But like I said earlier, those are qualifications for a hotrod (or a HybridZ ), not an everyday modern production car, which has to make power while having all kinds of other equipment (electronic controls, emissions devices, etc.) while still being very reliable, fuel efficient, and clean burning, in which case you need a more sophisticated design.

 

and Phantom (you're starting to scare me with the squishy hand thing ),

I think you're missing the point. Americans don't want big heavy gas guzzling low tech cars anymore. That's why sales slipped to the foreign competition over the last decade and a half. That's why the "big three" are now starting to put out cars of a similar nature. The average American consumer's tastes have changed. I don't know if I'd call that a "need" or a "desire", but it's true. That doesn't mean people don't enjoy hotrodding, it just means they want a 2.5-3.0 liter SOHC/DOHC, VVT, v6 (say Accord, or Camry, or Maxima, etc.) in their everyday car instead of the crummy 3.8 liter OHV v6 (say Lumina, or Stratus, or Taurus, etc.) and they also want good build quality, nice interior materials, practical ergonomics, RELIABILITY, and on and on, all at an affordable price. Detroit is not quite there YET. And according to HOTROD magazine, there is a replacement for displacement: TURBO / SUPERCHARGING. Its pretty much the only way to make a 4 cyl get any kind of power equal to a decent V8 (unless you're comparing some anemic '70s V8, in which case a well built N/A 4 cylinder could do it).

 

I'd also like to point out that the 4.3L V8 in Lexus/Toyotas, and the 4.5L V8 in Infiniti/Nissans make 340 HP, both are DOHC, VVT, are very docile, incredibly reliable, are classified as LEV (low emissions vehicles) and are capable of much more, thanks to their wonderful design. And they don't have to rev very high to make the power either. I don't want to sound like I'm not giving the LS1 enough credit, because although I have explained my point about the LS1 not being high tech, I did say it has a cool EFI system. It's an open-loop, direct-injection setup, and it's very cool. But that's the only thing on the LS1 that's new, and it's pretty much standard issue on most nondomestic engines. The LS1 still has the inefficient OHV, 2 valve per cylinder setup, with a single, NONvariable camshaft. And there are many other amazing technological advances in modern engines that the LS1 does not have, and that are hard to find on any domestic, such as oil cooled pistons, distributorless coil-on-plug ignition, variable length intake manifolds (awsome), hollow camshafts, forged titanium parts like connecting rods and valves/springs, etc. But Detroit IS starting to catch up, like I've been saying this whole time.

 

Oh, and that Caddy V12 made me drooooollll But I heard later on that they weren't going to produce it, that it was only for show-purposes?

 

Keep the great ideas coming.

Later

[pparaska]

vegeta, there's alot I could say, but I don't have the time. One minor point, most people, when told to relax, do just the opposite.

 

I think you keep missing the point about DESIGN for the intended use, and KISS. For the DESIGN parameters of the C5, the LS1 does all it needs to, with the "low tech" stuff you talk about: 2 valves per cylinder, cam-in-block, non-VVT, activated by pushrods get the job done, simple as that. No need for all the extra rotating and reciprocating parts that 4 valves per cylinder, VVT, bring along. The cost is lower, and the number of moving parts are lower, increasing reliability, most likely reducing friction as well.

 

4 valves per cylinder are only really needed if you plan on reving the engine. In the LS1, 2 valves make plenty of power to 6 grand.

400 crank hp. Going to OHC, 4 valves/cylinder, VVT isn't needed for the DESIGN parameters (high, table-flat torque curve from 1500 to 6000 rpm) of the C5. So why would GM spend the extra development and production costs, if it's not needed? It's called KISS. And it's one of the reasons that the C5 is spoken of as the best bang for the buck in the sports/GT class.

 

4 valves per cylinder, without VVT that basically shuts down the second set of extra valves, kills low rpm response, since it lowers the port velocity. To make a 4 valve/cylinder engine have any low or low-mid rpm torque, you HAVE to go to VVT. Otherwise, you likely get a high rpm torque band. And the GM engineers decided that was NOT in their DESIGN parameters.

 

It really is FORM following FUNCTION. And not over-engineering the engine just to please those that think pushrods are a joke.

 

The EvolutionVIII and WRX STI must be comparatively BEAT ON to get the performance the C5 delivers. Nothing wrong with that, as long as you're willing to always have the engine screaming at the right rpm, etc. Great for a race car, no doubt! But many of us would not want to have to beat on our street cars to get the performance. Hence, the low revving, unsophisticated, large displacement, pushrod V8.

 

Having said that, I'd LOVE to have 4 valves/cylinder and user tunable VVT on a large displacement V8. That's been my dream for over 20 years now. Of course, I could just buy a new BMW 745iL engine and have that - with almost complete control of the valve events. But who'd foot the bill?

[Guest vegeta]

Pparaska,

You know, you're a pretty cool guy when you're not pissed off

And I'll try not to say "relax" next time (he he)

I do agree with a lot of what you said, too. Like I agree that the C5 is excellent bang-for-the-buck, although I'd say a WRX STI or EVO8 or 350Z are also pretty damn good bang-for-the-buck. And I agree that a 745i powered Z would be one of the most badass hybridz's ever, and that unfortuneatly, noone is ever going to foot the mile long bill for it (I know, it makes me sad too).

 

But as far as the 4 valve design not being right for a small block chevy, I think you are quite mistaken.

Check out this website

 

http://www.ronsraceshop.com/companies/araoeng_chevySB.php

 

They sell custom 4 valve heads for SBC/BBC/SBF, etc. That's right, its not a typo! These heads retain the OHV design, but use special rocker arms to actuate the extra valves. As the site says, with these heads, at 6000 RPM you can have 474 hp from a 350 chevy with an LT1 cam and 750cfm carb. Thats a sh!tload more power than a new Z06 vette, and that was with a carb, for cryin out loud! Plus it had a very flat torque curve. Even the Z06 doesn't reach peak torque until 4500 RPM. Image an LS1 with 4 valve heads!!!! These heads are only expensive because its a limited production specialty part. Any manufacturer could mass produce something like this for way less money. So imagine a modern SBC with 4 valve heads and you see why I feel the way I do. Come on, even you die-hard old-school guys gotta love that!

 

And more about the vette, all I have to say is that Chevy could have done like Ford and AT LEAST made the newer SBC's SOHC. OK, fine, so they dont want the extra technology and advantages of DOHC and VVT. And OK, so they wanted it cheap and simple. So why didn't they just go SOHC? A SOHC is much simpler than OHV, and is smoother, more reliable (less moving parts) less friction, so even for a 2 valve non-VVT type head its a better choice. And it would be cheap, too. Don't try to tell me its not cheap, because Ford puts those SOHC 4.6 engines in all kinds of cars/trucks that are WAY cheaper than a vette (like the mustang gt, F150, etc).

 

That's all for now.

Later

[fl327]

The Japanese would make engines a whole lot bigger if the JDM cars didnt get taxed a bunch for over 2 liters. The 4cam Lotus Lt5 SBC put out the same, maybe even a little less hp and makes torque later in the powerband for sure than the LS1, and that was DOHC with a 16 runner sequential port intake and a bunch more stuff. The Japanese stuff has to be high tech, they have to work with a smaller engine in general, just makes sense. Chevy has been toying with the idea of OHC SBCs since the 60s, and pushrods it is.

[Phantom]

I just looked again at the torque "curve" on my LS1 dyno sheet. It is at 90%+ of maximum torque from 1,500 to 5,400 rpm with the maximum torque being 326 lb-ft. We have to be careful about making statements about where maximum torque occurs on a power band and look instead at the shape of the "curve" In the case of an LS1 it's more like a plateau.

I've seen too many cars - especially NA high revving I4's that have an extremely peaky torque curve that forces them to remain in a very narrow, high rpm band. The Honda S2000 comes to mind. Great car but you have to thrash it to move it.

Evo VIII & STI - let me boost the engine of my Z and they'll never get close on a dry road (can't beat the 4wd in the rain, even with boost). You are correct, the big move in the 80's to turbo-charging was to still maintain some semblance of performance while improving fuel economy. Then they learned how to do it without boosting (electronics, VVT, etc.). Now boosting is found only on the expensive models of most cars. It is there so those that want more performance than the standard engine can deliver can get it from the "standard" engine with boost. This saves the OEM money in developing a larger engine. Economics. I've run against an STI on the track. I beat him with a 2nd gear start and my 1/4 times fall between a stock C-5 and the Z06.

Another thing, look at the top ten sellers and tell me that Americans are now buying the small cars. I see a lot of mid-size sedans, SUV's & pick-ups on that list. YOUNG people are buying the small cars because they can get something cool and that's fun to drive for a reasonable $$$. Economics again. When they get older and have 2 kids they'll also have at least one large car, and that may be the only one they have. I have two Z's and a Suburban. I drive my Z daily but last week when I went to Branson I drove the Suburban and towed the Z. I like my comfort and am not up to 6-8 hours in my Z. It would have made the trip but I wouldn't have. I think many people here will agree with that.

All these vehicles have their place and most of them do a good job of doing what they were designed to do - some of them an outstanding job. Approaches to achieving those goals are as varied as paint colors. I'm seeing reports of hybrid gas/electric vehicles that will outrun and out mpg their gas only counterparts. Fuel cell development is getting closer and closer to marketability. The face of the market is continually changing but much of it is built on "old tech" just with a fresh appraoch.

[tannji]

I drove my Z with original seats 2000 miles home when I bought it.... and had no real complaints. I may have done a lot of stretching every gas break, but I was grinning all the way home. Not having had a Z for about 14 years probably had something to do with my tolerance, tho.... The looks, questions, and cussing when I opened the hood probably didnt hurt either.... 8)

Like Phantom, I have a people carrier (4Runner) and then the Z. The truck has its strong points, and I appreciate its versatility for our family, but I love nothing about it.

I think the optimal engine setup is possible only with possession of 2 Z's... one with a SBC, the other with a beefy L series motor. Both setups have so much to offer experience-wise, I always feel like I am missing out, no matter which one I am driving.

[johnc]

As my friend the Civil Engineer says, "Any Wanker with unlimited time and budget can build a bridge but it takes a real engineer to build a bridge with no time and no budget."

 

Thinking along those lines, I have much more respect for the designer of the original VW Bug then I do for the designer of the Ferrari Enzo. I think that's what Pete's trying to say.