NW-99SS

iTrader: (6)

I think he was referring to the bolded part??

It'llrun

V8 "Cammer" engines weren't banned from both NHRA(TF) and NASCAR because they were inadequate. They were banned because they basically made the competition null and void.

There is much more to this than how the fuel is burned, like how much fuel is burned, how quickly it's burned and how efficiently it's burned.

In the end, the valve is indeed opened at X rate for Y amount of time... OHC can surely make those rates and times increase or decrease and for a pushrod engine to do the same, more work is required to cover more moving parts. It has been done, of course. It just takes more effort.

You don't see why OHC would be considered moving forward? Well, there's not much help for you on that, unless you simply pay attention to the automotive world once in awhile. In automotive terms OHC engines have been around nearly forever, true. The abilities of them, however, weren't truly recognized in America until the 1980's and not in earnest, till the 1990's.

It'llrun

The reality is, they DO need to do better, period. In order to do better, they will eventually be forced to drop OHV engines altogether because our government WILL mandate that by ever more tightening EPA rules/ CAFE standards.

Looking at it as you are, I agree.

Conversely, if a company does as Ford did with it's Modular V8 lineup, for example, that company can cut its overall budget on V8's, thus saving production costs. Ford has taken a slightly different approach with the Ecoboost lineup and GM has followed suite with it's Ecotec offerings. Instead of using so many interchangeable parts as the V8's did, they are using a few engines in the entire lineup. You can get the 3.5L in the pickup, the Explorer, the Taurus and some Lincoln offerings. The 4cyl Ecoboost lineup is large, to say the least, but many of these are all but identical in design, which saves money. GM's Ecotec is available in several models as well, in various forms. Chrysler now does this as well, but they are (from my view) even more crossed up than GM on engine choices.

Engine to engine, anything is possible. That said, often we see the more economical engine passed over by the "lower emissions" engine and OHC engines have long been stated as cleaner, but less efficient. With DI incorporated into the 5.L(which it was designed for), it will get better economy than it does. Expect this for the 2015 model F-series and probably, the Mustang.

The problem is, our government doesn't want OHV engines to continue... That's that. Due to that problem, and because we're of the belief that OHC engines can burn cleaner, we're already seeing more OHC.

Couple that with the relatively true statement that OHC engines also use more fuel and noting that our government also wants more fuel burned(no matter what they say-based on their own implemented rules), it only makes sense that they(gov't) will "push" out pushrod engines.

Besides, consider the result of a DOHC 7L with a supercharger... or a 6.2L DOHC with that or a TT setup...

Oh... I was talking about balance of the car, along with weight. Of course, I wasn't talking about anything with a power adder. Those add weight, period, but had nothing to do with what I was saying.

NW-99SS

iTrader: (6)

I think the real future in valve events belongs to Koenigsegg with their valve actuator technology. It supports RPMs well past 14000 and uses air to function the actuator. Of course this tech is years away and only in R&D.

The OHC vs OHV arguement will go on without a clear winner. I think the only reason OHC "appears" to make more power is due to the fact of running 2 cams and 4 valves. There is the arguement the the SOHC, 2V/Cylinder engine is not as efficient as its OHV counterpart as well due to lengthy timing chains, and turing 2 cams vs 1. The real limiting factor it seems is the 2V/Cylinder for cam-in-block applications. It's fair to say GM has optimized the OHV/pushrod motor nearly as far as it can go with the new LT family of DI V8s, where they go from here is anyone's guess.

I still think the importance of the valve actuators is significant. Smaller engine blocks due to no cams, no timing chaings, plus save the rotational mass and energy required. Of course the air supply would need to be addressed, and a pump is a parasitic loss for sure, then again, almost all new cars have an AIR pump for smog reasons.

JD_AMG

Please explain how a highly restricted and regulated racing series pertains to street production cars. That is what is being talked about there.

I think you may not be reading between the lines here. Im pretty sure everyone is talking about V-shaped engines (not inline engines), specifically V8 engines.
Do you know of any other engine out there thats both smaller, lighter, and makes more power and torque than the LS7? Whats that? There is none? Hmmm... What were you saying about OHC engine being superior?
On the same note, why do so many hot rodders (of all makes, Ford included) swap GM's OHV V8s into their rides instead of these "superior" OHC V8s?
Why do all these independent supercar companies use GMs V8s for their cars and not Ford's mod motors or the new Coyotee engine?
Sure if you are going for as much power as possible with limited displacement, and no care about weight or size an OHC V8 would potentially make more power, but this is the real world where weight and size matter and there are no displacement restrictions, so its a moot point.

JD_AMG

Says who? What stake does the government have in actual engine setup, as long as the EPA requirements are met? Ask yourself, why would they honestly care? Better yet, do any or them actually know the difference?

The Japanese and Europeans have displacement regulations and taxes, they have been using OHC engines forever. Currently those brands are seen as "superior" to the American brands, and naturally the American brands are going to mimic what is seen to be better to try and win back market share. V8s have been seen as "gas guzzlers" for years and years now, V6s are (have been) becoming a popular "standard sporty" engine for cars. In order to keep up with the power and image the foreign V6s are making, the Americans needed to jump on board with OHC V6s.
The V8s are a totally different story, as should be blatantly obvious and GM is making a ton of power and torque out of their smaller/lighter/cheaper OHV v8s vs their competition.

Imagine the massive size and weight it would be. What would it possibly fit into? A large truck? For comparison Nissans VQ 3.5L V6 is physically bigger than the 7L LS7, now imagine a bigger block with more cylinders and FI...
Besides what would be the point? If a lighter/smaller/cheaper OHV 7L V8 makes the amount of power a manufacturer is shooting for then why would you want the overweight/oversized/more expensive engine?
when manufactures make a car they have a set power goal. They don't just have an engine sitting in front of them and decide to try and make the most power for its displacement. If they are shooting for, say, 505hp, and close to 500ft.lbs of torque, and they have an OHV engine that will easily hit those numbers that is also lighter/smaller/cheaper than a comparable 500hp OHC V8, then why would you not go with the OHV engine?

Zac_Speed

iTrader: (4)

Z06- N/A ZR1- Fi.. Period

SparkyJJO

iTrader: (11)

Pointless. That's racing. Has nothing to do with daily drivers and emissions.

How the valve is opened has no bearing on the amount, speed, and efficiency of the burn. The the timing, speed, duration, etc of the valves is what affects that (among other things like spark temp, ignition timing, etc). OHV vs OHC does not matter here as they can both open and close valves at whatever rate desired, up to an RPM limit. Sure, in theory OHC can hit higher RPMs easier, but the redline means what for emissions again?

I grant you that.

That's a really weak argument

Like I already said, OHV and OHC each have their pros and cons. But the mode in which the valve is opened isn't in of itself going to affect emissions.

It'llrun

Koeinigsegg not withstanding, I thought the technology was probably further along.

I think there is a clear winner, but, as you've pointed out, it isn't the 2V of either. If the OHV comes back in 4V form, it can contend. Obviously, we already know those are and remain expensive. Plus, DOHC offers better control of timing events by design.

Yeah, but there was the LT5...

OHC??

Considering the lack of parasitic loss by not using a cam, etc. inside the engine, I think the addition of an air pump would be a blessing. Now, will that also be used to oil the top of the engine??

It'llrun

In 1969, you could actually buy the car with the engine... No emissions... The government hadn't decided to screw the citizen on that just yet.

The point is as it was. That old OHC engine kicked *** to the point that other companies protested and the sanctioning bodies forced them to be eliminated.

I didn't utter 1 word here, about how the valve is opened. Like you, I merely pointed out things that do matter.

EUREKA!

Sometimes the truth isn't very strong... Still the truth.

Yup, and in automobile terms, the OHC, spefically DOHC, has more pros and the OHV has more cons.

Fact is, some engines just do burn cleaner than others and in the case of OHC vs OHV, it seems the automotive world has determined the OHC is cleaner. I remember when Ford came out with the 4.6 and the big news was that it needed no smog pump(parasitic loss) to pass emissions. That was what, like 1990... The OHV needed till around 2006 for that. Apparently, the test equipment was either partial to the OHC engine, or it burned cleaner... You can judge that for yourself.

NW-99SS

iTrader: (6)

LT5 was OHC, and I know GM made it(actually Lotus), but it has 4V/Cyl which is why my point alluded to 2V/Cyl being a restriction for cam-in-block (although GM tested a 3V head for the C6Z06, it just didn't make any more power than the 2V setup with the added valvetrain components).

Funny story about the LS1, there was an OHC motor developed at the same time. The R&D department installed the LS motor and the OHC motor in separate Corvettes and let the Exec's take them around the proving grounds. The unanimous decision was made to go with the OHV without knowing which was which.

I'm not against an air pump, I can't wait for air actuated valves to finally change the internal combustion engine for the better. Imagine not being limited to valve float and timing chains!!

LilJayV10

iTrader: (39)

Someone thought bringing Fords 4.6 into this argument was a good idea?

I'm speaking off the cuff here and after a "few" drinks after work but how long did it take Fords OHC technology to catch up for GM's OHV technology?

The LS1 was introduced in what? 97?

When did the new 5.0 Coyote engine come out? 2010 I think...maybe?

I remember when GM released the LS1 and how everyone said they were going backwards staying with OHV....

It'llrun

Yeah, that's why I mentioned it... Has been done and can be competitive, but at a seemingly higher cost.

Didn't know that, but I'm not surprised. Low end grunt sells performance cars and OHC engines don't have it like OHV does.

There was a cylinder head available back in the 90's, by "COATES" and it seems to have eliminated most of those parts, though I can't remember the details. Air pumps are great, when they're used for helpful things... which don't include adding air to the exhaust system, unless it's a turbocharger!

Not long in reality. Why do you think GM kept increasing cubic inches, because they made so much power with 281? Oh, that's right... They used 346 to over-match the power of the 4.6L DOHC. Besides, Ford isn't the only company to offer an OHC engine and many have long since caught GM's LS1 technology... Hell, there are 4cyl powered cars today which are as quick as the LS1 cars were in 1997. There have been for quite awhile, for that matter.
Yup

May of... but since you mentioned Ford specifically, you shouldn't then follow with merely another more capable engine. The 2002 delivered 2003 Cobra would easily compete with the LS1. When used in Camaro, the LS1 was defeated by the 4.6L and yeah, I'm aware Ford used a supercharger. They also used IRS. You don't see me whining, nor do I see you whining that Buick had a turbo on the GN, so... Apparently it took Ford between 4 and 5yrs and that completely excludes the 1996-2001 Cobra models, which did compete when driven well. It also ignores the 5.4L entirely. That engine, used in the 2000 Cobra R, easily ran 12's on the 1/4 and would hit 170 plus on the open road, all stock.

I don't remember anyone saying they were going backward. After all, they merely created a newer evolution of an engine they'd essentially invented in 1953-54 and, like the LS1, released in the ('55)Corvette.

I am sure that people said GM wasn't moving forward and, if you remember the LS1's arrival, you may also remember how long it was before anyone truly got it to perform notably better than GM delivered it. I remember in 2001, 11's would damn near make you famous!

Anyway, back to the future... CORVETTE TODAY!

LilJayV10

iTrader: (39)

You obviously have this **** figured out and it will require way more time on my part than I care to spend to be able to make any factual response. Long live cammers!

I agree, this has gotten off track and I apologize if I had any part in it.

It'llrun

At least you paid attention to my sig and, realizing you have no more argument, decided to quit. Good on you!

Btw, the next thing I probably would've reminded everyone is that GM itself offered the "dreaded" 4.6L DOHC in several Cadillac models and basically all of them produced 275-300hp. Point is, it's not about Ford vs Chevy here. It's about advancing technologically and appeasing the powers that be and GM can do it. Quietly, it looks like they are doing it. Speaking of Cadillac, they offer the 3.0L V6 now, rated at 270hp... Not bad for any engine, let alone a 3.0L V6.

Long live CORVETTE!

assasinator

so when the LS series goes the way of the dinosaur, they should still use it?

Marc 85Z28

iTrader: (8)

That's because you live on the internet rather than at the track. Several locals were in the low low 12s and even 11s with bolt-ons and mild weight reduction back in 1999. Whisper lid, Grots, cutout, and PI converter with slicks would do it under 3400lbs. And they did it without tuning or internet help.

JD_AMG

No response to my post huh? Typical...
Significantly higher cost, higher weight, bigger mass and little real world benefit. There was experimental LT5s in the C5 chassis, engineers had totally reconfigure the front chassis to fit the LT5, because it was so big. This hurt all performance aspects.

No. Both engines had very similar outputs, even low end. The difference was the OHV engine made the car lighter, and better balanced while having no downsides.

Again with the ricer argument of CI, as if it matters.
Why would you not increase CI if there is no downside? If the engine remains the same physical size and weight, yet power and torque increase, how is this a negative thing?
Ford had to move to 2 cams/cylinder and then FI to match GMs "old tech" pushrod engine, and even fell short if it.
How many 4 cylinder N/A cars today can run low 13s? Maybe the 1900lbs Elise with a perfect run? And thats it?

Cute. The 5.4L, which was the size and weight of the Vipers V10, finally made the mustang competitive.

JD_AMG

Funny you bring up the Northstar, here is GM's response on that:
"So if the pushrod design makes such a good V-8, why does GM make a DOHC V-8 Northstar? "I'm not going to touch that one," laughs Winegarden. GM's party line is that some customers want what it calls "high-feature engines." Winegarden does admit there are some refinement benefits to the DOHC layout, but personally, I don't find the Vette's engine to be a bit unruly. " - interview from Car and Driver.
They even admit its about marketing, not performance.
The Northstar made less power than the LSx's while being heavier, bigger and more expensive. Another point to the pushrod engine...

JD_AMG

These images never get old...
4.6 vs 5.0


LS2 vs VQ 3.5L V6

4L 1Uz V8 vs LS1