2006 Chevrolet Corvette Z06 @ the N-Ring

[JNasty4G63]

.....as for the engines smaller than the lexus, BMW had a 3.5 liter v8 recently, mercedes had one till about the mid eighties, lotus has one in the recently deceased esprit turbo, ferrari had one that was about 2.8 liters back in the day. there are plenty of small capacity engines of less than 4 l displacement in the annals of automotive history. there are (were) V12s of two liters for crying out loud.

Well, I understand that back in the day there were all sorts of crazy engine sizes. Thats not news. But, I'm talking current engines. Saying the V8 used in the current Corvette is smaller than "many V6" engines used these days is whats troubling me.

Yes, there have been some very small V8 engines. There have also been some real fricking huge ones. Chevy has a crate motor you can order from GMP that measures in at 572ci. Thats 9.4, yes NINE POINT FOUR, liters of giant motor. But, in the current crop of mainstream V8 engines, you don't have many much smaller than 4.0L or so.

Hilg

 

[Driftster]

Well, what about the Boss 10.0 Liter?

I mean there's 10.L stangs drivin around florida....

 

[JNasty4G63]

Well, what about the Boss 10.0 Liter?

I mean there's 10.L stangs drivin around florida....

I assume you're talking about the Mustang that was in R&T in '95. It was a 429 bored out to 605ci. Thats only 9.9L, but everyone just called it the 10L BOSS because its just so damn huge. Not very common, much like the GMP 572. A 429 is very big, and you will hardly ever see them. They are just so big, you have to do some MAJOR work to get them in a lot of cars.

Hilg

 

[Driftster]

Oh I know. the SVT "concept" that didn't break 8 in the production #'s, but still sold.

Yeah, i know....A hell of alot of work, but done none the less.

 

[JNasty4G63]

Well, either way, those engines are complete opposites of what I'm talking about. I'm talking about current production models. In the realm of current production, there are very few, if any, V8 engines under 4.0L in size.

And anyway, we aren't even really talking about displacement here. The main issue we were discussing was the ACTUAL size of the motor. And, I still stand by what I say. Barring any strange comparisons in production car terms (Like small performance V8 and large truck V6), you won't find many V8 engines that are smaller size-wise than most V6 engines.

Hilg

 

[Driftster]

Well there are quite a few if you're talking about mass of the engine, but I'm just splitting hairs.

 

[skicrush]

Well, I'd love to hear the others. Like I said, I don't doubt there are some small V8 engines out there. But, using a very small V8 and a very huge V6 as a common comparison is kind of silly.

And , the 4.3L V8 that Toyota/Lexus uses is a very small V8. It only has a 3.5" bore. Thats very small, its only a mere 5mm bigger than the 2.0L 4G63 in my Talon. The Vortec 4300 in your truck has 4.00" bore, so its a very big V6 engine. Once you add all the ancilliries to that, you have a large engine. And also, the Z06's 7.0L V8 has a 4.125" bore. Thats nearly 3/4" bigger per cylinder than that Lexus engine. So, just in that, you have nearly 3 inches more length from end to end.

Again, I don't doubt there are some big V6 engines, and some very small V8 engines. But, trying to convince me that the 427 in the Z06 is a "very small" V8....well, its gonna take some good hard convincing. Even with the dry sump and the somewhat shortish intake manifolds on the new LS motors, we're still talking about a lot of engine.

Hilg

I can easily understand your disbelief. Let's put it this way. The Z06 is an OHV engine--the valves are higher than the cam--and there's only one cam. Most V-8s (pretty much anything that isn't in a truck) and most V-6s running around these days, and almost EVERY eninge in any kind of performance car is a DOHC motor. In DOHC engines, there are 2 cams, and a lot of extra parts to operate both those cams. Both of those OVERHEAD cams. Your center of gravity is rising, as well as the overall weight of the engine. Of course, the dimensions will be different--the vette engine will be longer, but it will also be shorter (edit--not as TALL), and can easily weigh less than a DOHC V-6.

Another thing to consider is that the Z06's 7.0L/427cid is still a SMALL BLOCK--same basic block that the 5.0L (305 ci) used to use, except they've shaved the insides. So, the outside is no larger than it has ever been, but there is a lot less mass on the inside because the larger displacement.

And yes, Hilg, there are a lot of expensive components in the engine, titanium and so forth. But it is a very simple, durable design (same basic architecture as the truck engines), and is very cheap, simple, and reliable compared to other VVT/DOHC engines found in other high end cars. I have no idea what engines for other sports cars cost, but the engine for the Z06 costs about $15k as a crate motor. Anyone have any numbers to compare?

 

[JNasty4G63]

.....Let's put it this way. The Z06 is an OHV engine--the valves are higher than the cam--and there's only one cam. Most V-8s (pretty much anything that isn't in a truck) and most V-6s running around these days, and almost EVERY eninge in any kind of performance car is a DOHC motor. In DOHC engines, there are 2 cams, and a lot of extra parts to operate both those cams. Both of those OVERHEAD cams. Your center of gravity is rising, as well as the overall weight of the engine. Of course, the dimensions will be different--the vette engine will be longer, but it will also be shorter (edit--not as TALL), and can easily weigh less than a DOHC V-6.

Well, thanks for the engine lesson, but I already know what the hell OHV and DOHC engine designs are. And, just because an OHV engine doesn't have the cam up above the engine means nothing in regards to engine height. In an OHV engine, where you normally would have a camshaft, you have rockers that push the valve open. The camshaft pushes up on the pushrod, which in turn rotates the rocker, which then pushes open the valve. Those take up just as much space as a cam. You make it sound like an OHV engine has nothing but open ports above the piston. There is just as much going on under the valve cover of and OHV engine as a DOHC engine, so the supposed complication and "center of gravity" difference is going to be null as well.

Another thing to consider is that the Z06's 7.0L/427cid is still a SMALL BLOCK--same basic block that the 5.0L (305 ci) used to use, except they've shaved the insides. So, the outside is no larger than it has ever been, but there is a lot less mass on the inside because the larger displacement.

Again, yes, I know what the hell a small block is. Have you ever seen an LS motor out of a car??? The LS engine, while not huge, is still a very sizeable motor. Just because they call it a "small block" doesn't mean we're talking about a tiny engine.

And, the "shaving out" of the insides as you refered to it is called "boring out" an engine. The bore measurement of an engine is the diameter of the hole in the block in which the cylinder moves up and down. But, they didn't just bore the current 5.7L LS2 engine to get it up to 7.0L in the Z06. To get a small block all the way up to 427ci, they've had to give it a bigger bore and stroke. But, they did all this with a new engine casting, new internals, and all new front assembly parts. So, its not like they just took a current production engine, and bored the hell out of it to make it 427ci. Its a ground up new engine. And, like I said, even thought its still a "small block" engine, its still a fairly large engine.

And yes, Hilg, there are a lot of expensive components in the engine, titanium and so forth. But it is a very simple, durable design (same basic architecture as the truck engines), and is very cheap, simple, and reliable compared to other VVT/DOHC engines found in other high end cars. I have no idea what engines for other sports cars cost, but the engine for the Z06 costs about $15k as a crate motor. Anyone have any numbers to compare?

Well, I'm sorry to burst your buble, but $15k is a huge chunk of $$$ for an engine. Not sure where you even got that number, but if that is true, that engine is ridiculously expensive. Regardless of what the actual cost is, it should be expensive. It is a complete ground up design just for the Z06. Unlike the LS2 in the base Corvette which is shared with the GTO and SSR, and shares basic design with the truck engines, the LS7 is built by hand only for the Z06. That is not cheap to do.

And, just because an engine is DOHC or has a variable cam design doesn't exactly mean that they are "expensive" or "complicated" to run. I mean, Honda's VTEC design just measured RPM, and then when a preset speed was reached, it would open a little oil flow port, lock a set pin, and engage a separate "high lift" lobe on the cam. Many others just use a variable cam sprocket to adjust the duration and actuation of the cam lift, all of which is just run by the ECU. Yes, there are a couple more parts involved in that. But, variable cam engines have been around for over 15yrs now, they are hardly rare, expensive, or complicated now.

Hilg

 

[Dave A]

The engine designs that offer the lowest center of gravity are found in Porsches and Subaru Impreza's. JNasty, while you raise some valid points theres no need to be confrontational, he described certain configurations of engine, while it may not have been complete theres nothing wrong in describing them if not for you're benefit for other members benefits.

 

[skicrush]

No kidding--I mean, its not like I said your momma fed you with a sling shot, even if she did. And thanks for the vocab lesson--I feel much more comfortable now knowing that you are COMPLETELY fluent in motor speek. I guess your ignorance in the first part of this thread fooled me.

 

[JNasty4G63]

.....And thanks for the vocab lesson--I feel much more comfortable now knowing that you are COMPLETELY fluent in motor speek. I guess your ignorance in the first part of this thread fooled me.

And, what ignorance might that be??? I've been very minimal in this thread, and very non-confrontational. The way you phrased that last post of yours sounded to me like you were trying to speak directly to me. I'm talking about engine sizes and dimensions, and then you chime in with.....

I can easily understand your disbelief. Let's put it this way......

And then you go on to give me a disertation on the dynamics of an engine. If, like live4speed suggested, you were just trying to put that info out there for other people, then you should have stated so. But, the way it is, it comes across like your trying to teach me about engines. I don't need help.

Also, I never did call anyone names. But thank you for taking that first step and calling me ignorant. You, the person who thinks a $15k hand built 427 is a cheap motor. You, the person who thinks because an engine is a "small block" motor that its not that big. You, the person who thinks that "shaving out" or boring an engine block somehow saves a lot of mass. And you, the person who thinks that an OHV engine has a discernable difference from a DOHC engine in regards to center of gravity. You did say those things, right???? And, you called ME ignorant??? Ok, just making sure.

Hilg

 

[skicrush]

And, what ignorance might that be??? I've been very minimal in this thread, and very non-confrontational. The way you phrased that last post of yours sounded to me like you were trying to speak directly to me. I'm talking about engine sizes and dimensions, and then you chime in with.....

And then you go on to give me a disertation on the dynamics of an engine. If, like live4speed suggested, you were just trying to put that info out there for other people, then you should have stated so. But, the way it is, it comes across like your trying to teach me about engines. I don't need help.

Also, I never did call anyone names. But thank you for taking that first step and calling me ignorant. You, the person who thinks a $15k hand built 427 is a cheap motor. You, the person who thinks because an engine is a "small block" motor that its not that big. You, the person who thinks that "shaving out" or boring an engine block somehow saves a lot of mass. And you, the person who thinks that an OHV engine has a discernable difference from a DOHC engine in regards to center of gravity. You did say those things, right???? And, you called ME ignorant??? Ok, just making sure.

Hilg

I don't really feel like going point for point with you, but we sure can.

1) How much do the following engines cost? And how muh do they weigh? I've found a weight of about 400 lbs for the LS7, but I can't confirm that. Shipping weight for the LS7 crate motor is 490 lbs. Not that they sell them as crate motors like chevy will, but...
A) Ferrari 360, 430, enzo
B) 911 Carrera, 911 turbo, GT3, Carrera GT
C) Aston Martin DB9, Vanquish S
D) Murcielago, Gallardo
E) M5
Need I go on? Do you really belive that ANY of these engines are actually cheaper?

2) Yes, the LS7 is assembled by hand, but it is built on the same line as the LS2 motor (which gives GM a lot of flexibility to meet varying levels of demand). Which is close enough to the same old basic block that arguing about it is just silly.

3) I never said a small block was small--just smaller than a lot of smaller displacement DOHC motors, and yes, lighter. And who do you think you're fooling saying that a larger bore wouldn't reduce the overall weight? Not a ton, no, but some--larger displacement is CERTAINLY not going to ADD weight. The LS7 is no bigger EXTERNALLY than the old 5.0. So let's see, steel's density is 8 g/cc, or kg/l. So 2 liters is 16 kg, or 35 lbs. No, that's not a ton. Even less, the more it comes out of the aluminum block than the steel sleeves. But for taking up the same amount of space in the engine compartment, that's pretty darn good.

4) How on earth can you argue that a DOHC is NOT more complicated than an engine with a single cam? There's a cam for each bank, rather than just one for both--ie, MORE COMPLICATED. Impossible? Obviously not. And again, is it lighter? No again. An extra cam and chain are certain to weigh more than the pushrods and rocker arms in an OHV motor. And being overhead, they are certain to raise the center of gravity.

ALL little things, that all together make some slight difference. Nothing to get so steamed about. I'm sorry if you took it personally--I didn't mean to offend or provoke, but my wife is pissed at me right now for a very similar reason. So we'll give you the benfit of the doubt--it's probably just me this week.

 

[JNasty4G63]

Do you really belive that ANY of these engines are actually cheaper?

You missed the main arguement that I had there. We're talking about a SMALL BLOCK PUSHROD V8 engine here. Yes, compared to those other engines, I'm sure its competitive. But, some of those other engines were V10 and V12s, so hard to directly compare. But really, you still think $15k for a 500hp pushrod V8 is a good deal???? Its a nice engine, sure. But, if the price you found is right, thats a big pile of $$$$ for a pushrod V8 engine.

3) I never said a small block was small--just smaller than a lot of smaller displacement DOHC motors, and yes, lighter.

Ok, you find me some ACTUAL FACTS to prove that, and I'll gladly agree. But, as is, I fail to see how it could be "smaller than a lot of smaller displacement" engines out ther.

And who do you think you're fooling saying that a larger bore wouldn't reduce the overall weight? Not a ton, no, but some--larger displacement is CERTAINLY not going to ADD weight. The LS7 is no bigger EXTERNALLY than the old 5.0. So let's see, steel's density is 8 g/cc, or kg/l. So 2 liters is 16 kg, or 35 lbs. No, that's not a ton. Even less, the more it comes out of the aluminum block than the steel sleeves. But for taking up the same amount of space in the engine compartment, that's pretty darn good.

Well, that fancy math work you did there might mean something if all the engine size difference was in it's bore. But, its not. It only got 5mm bigger in bore. But, it got almost 10mm more stroke. Thats the one that ruins your math. A greater stroke does nothing for taking metal out of an engine. Just means the crank moves the piston up and down 10mm more in its ever so slightly bigger bore.

So, if you really think that taking 5mm of metal out each cylinder wall of an aluminum block engine is going to matter anything, you just go on thinking that. But, I doubt you'd see anything worth talking about.

4) How on earth can you argue that a DOHC is NOT more complicated than an engine with a single cam? There's a cam for each bank, rather than just one for both--ie, MORE COMPLICATED. Impossible? Obviously not. And again, is it lighter? No again. An extra cam and chain are certain to weigh more than the pushrods and rocker arms in an OHV motor. And being overhead, they are certain to raise the center of gravity.

First off, in a DOHC engine, there are 2 camshafts for each bank of cylinders. You're refering to SOHC. Either way, I don't recall ever saying that DOHC or SOHC was uncomplicated or less complicated compared with OHV. Neither one is really uncomplicated. Both have the camshaft driven off the crankshaft. Regardless of if there are 1 or 2 cams in the head compared to the camshaft in the block. Both are driven by a belt or chain directly off the crank. So, either you have a timing gear and chain in an OHV engine. Or, you have a longer chain or belt and 2 or 4 gears in a DOHC or SOHC engine. Both are driven, just with differing ammount of chain or belt. I fail to see the complication.

What I said was that many, but not all, variable cam designs do very little for complication or weight of an engine. Like I said, the VTEC that Honda used to use was just a small oil port and an extra lobe on the cam. Not real complicated and weighs basically nothing more than without it. And others are just an electronically adjustable cam gear. The actual hardware of a variable cam engine is not the complicated part. Its the ECU work that gets complicated.

My point is, when you take the camshafts off the top of the head, you have to have a whole rocker assembly up there to actuate the valves. Now, I know camshafts aren't feathers. But, to say that because they are up there as opposed to a rocker assembly is going to make any major discernable difference in cg is just silly. The only major thing weight-wise you have to worry about with an engine is block and head material. After that, any other changes are going to be minimal when refering to the engine weight as a whole.

Nothing to get so steamed about. I'm sorry if you took it personally--I didn't mean to offend or provoke

You called me ignorant. What else do you think I'd get steamed about or take personally??? Really man, think about it. I'm not mad. But, you call me ignorant, and then tell me not to take it personally. Thats a bit much.

Hilg

 

[Dottinger-Hohe]

gee whiz

 

[neanderthal]

the small block is a lot smaller than a lot of V8 engines, including the ford 4.6. there is an image of the two of them next to each (im runnning a search in another window) and the size difference is noticable.

AMG engines are reputedly in the high $50000 or more in terms fo price, so that $15K figure is low by comparison. valid comparison, bthe handbuilt, both V8s. i got the AMG price from a mercedes forum where a guy had an engine grenade and had the engine replaced under warranty. total bill was in the sixties. all free thanks to warranty.

OHV weigh less, much less than even a SOHC. and the position of the camshaft also means they have a lower center of gravity than OHC engines too.

search has been unsucessful. must go to sleep anyway.

 

[skicrush]

You missed the main arguement that I had there. We're talking about a SMALL BLOCK PUSHROD V8 engine here. Yes, compared to those other engines, I'm sure its competitive. But, some of those other engines were V10 and V12s, so hard to directly compare. But really, you still think $15k for a 500hp pushrod V8 is a good deal???? Its a nice engine, sure. But, if the price you found is right, thats a big pile of $$$$ for a pushrod V8 engine.

Ok, you find me some ACTUAL FACTS to prove that, and I'll gladly agree. But, as is, I fail to see how it could be "smaller than a lot of smaller displacement" engines out ther.

Well, that fancy math work you did there might mean something if all the engine size difference was in it's bore. But, its not. It only got 5mm bigger in bore. But, it got almost 10mm more stroke. Thats the one that ruins your math. A greater stroke does nothing for taking metal out of an engine. Just means the crank moves the piston up and down 10mm more in its ever so slightly bigger bore.

So, if you really think that taking 5mm of metal out each cylinder wall of an aluminum block engine is going to matter anything, you just go on thinking that. But, I doubt you'd see anything worth talking about.


You called me ignorant. What else do you think I'd get steamed about or take personally??? Really man, think about it. I'm not mad. But, you call me ignorant, and then tell me not to take it personally. Thats a bit much.

Hilg

I really ought to be asleep.

I called you ignorant AFTER you got pissed the first time. After Live4speed (not to drag him into it) made reference to you getting all confrontational. Which it still seems to me was part ambiguity on my part, and part overreaction on yours.

You make some very valid arguements, especially about the stroke (which I must admit, I COMPLETELY overlooked). But I think Neanderthal has very good point, too. I may have been overeager when I said it weighs less than some DOHC V-6s, but surely it weighs less than other engines with similar outputs. And smaller displacement definitely includes 5.7L and 6.0L V-12s (Lambo and Aston). I can't imagine that a rocker assemply weighs the same as a camshaft, let alone 3 camshafts. Now, a matter of maybe 10-15 lbs difference, 3-5 inches higher up in an engine that weighs 400+ lbs is probably not that big a deal. But it is enough to mention.

And your main point is that it is STILL a pushrod engine? I don't care if it's a pushrod engine--you're getting 500 horses out of it, aren't you? Why should it cost $20k like the 911 turbo engine I found on ebay (that puts out less power), or the $50k swap Neanderthal was talking about? How is that a bad deal? What SHOULD a 500 hp engine cost? $5k? $10k? What should a 500 hp, 23 combined (17/26) MPG car cost? There is no such thing. What should the most efficient 500+ hp engine in the world cost? Do you realize they could bond two together to make a 1010 hp, 950 lb-ft torque V-16 that gets the same gas mileage (8/13) as the Carrera GT or Enzo?

More importantly, why is it never, EVER, good enough?

 

[JNasty4G63]

.....I may have been overeager when I said it weighs less than some DOHC V-6s, but surely it weighs less than other engines with similar outputs. And smaller displacement definitely includes 5.7L and 6.0L V-12s (Lambo and Aston).

Ok, fine. But those you are comparing a V8 with are V10 and V12 machines. Just because the "displacement" says they are similar, those engines still have 50% more pistons, rods, crank, block, cams, etc etc.... You see what I'm getting at??? Like I said, I don't doubt the Vette has a very light engine. An all aluminum small block isn't going to be overly heavy. But, when you tried saying it was lighter than many DOHC V6 engines, that was just silly. And, same with saying its somehow better because it weighs less than some V10 and V12 engines. It should, it has far less engine.

I can't imagine that a rocker assemply weighs the same as a camshaft, let alone 3 camshafts. Now, a matter of maybe 10-15 lbs difference, 3-5 inches higher up in an engine that weighs 400+ lbs is probably not that big a deal. But it is enough to mention.

I highly doubt we're talking about a 10-15lb difference between the two. I'm sure having cams up there does have a little more weight than a rocker assembly. But, its a very minimal and insignificant ammount. As I said, the only things weight-wise you ever worry about with an engine is block and head material. Thats it. The rest is insignificant.

And your main point is that it is STILL a pushrod engine? I don't care if it's a pushrod engine--you're getting 500 horses out of it, aren't you? Why should it cost $20k like the 911 turbo engine I found on ebay (that puts out less power), or the $50k swap Neanderthal was talking about? How is that a bad deal? What SHOULD a 500 hp engine cost? $5k? $10k? What should a 500 hp, 23 combined (17/26) MPG car cost? There is no such thing. What should the most efficient 500+ hp engine in the world cost? Do you realize they could bond two together to make a 1010 hp, 950 lb-ft torque V-16 that gets the same gas mileage (8/13) as the Carrera GT or Enzo?

Well, I still doubt your figures. And, I HIGHLY doubt neaderthals figures. He's saying an AMG engine costs $50k???? Which engine??? If we're talking about the V12-TT in the 65s, then MAYBE it would cost $50k. But, what about the 5.4 V8 in the C55 and SLK55??? Thats just a plain old V8, no turbos no supercharger. And, those cars only cost $55k and $65k respectively. I highly doubt those engines cost $50k. I could see maybe $30k for the V12-TT in the 65s, but not $50k. And, I can see maybe $10k for the LS7. You can't just blanket cover these engines with random numbers. If you show me some actual figure where an LS7 costs $15k, I'll understand. And actual figures where a specific AMG engine costs $50k.

But, you can easilly build an LS1 to that power level, or more, for much less than $15k. There are many F-body guys around here with 500hp+, many are all-motor. And I know none of them spent $15k to get it. Hell, my car has 560hp and the engine cost me $4500 to build, with a $1200 turbo. And, if I drive normal and civilized, I can easilly get 16mpg with it. I just think you guys are blowing these numbers way out of proportion.

More importantly, why is it never, EVER, good enough?

Who said anything about not being good enough??? I've said many times, I think the new Z06 is a fantastic car, has a fantastic engine, and is a great deal for the performance you get for what you spend. The topics we're discussing is where I have questions. Thats all. Show me some actual figures on what an LS7 weighs, costs, all that, and we can solve this real quick. But as is, you guys are just bringing up random figures and going on that. It doesn't work that way.

Hilg

 

[Dave A]

I think it was AMG's V12 as used in the CLK-GTR cost 50k. 50k is what you'd pay for the very best fine tuned road engines around not something like the AMG V8.

 

[skicrush]

Looks like I was off. It's $16,995. http://www.ls1tech.com/forums/showthread.php?t=359103 That's not exactly great news. I'll ask neanderthal to keep looking for that comparison between the ford and chevy motors.

[edit] OK< I found someone who put it better than I have. http://66.102.7.104/search?q=cache:...?p=120257+LS2+ford+4.6++size+comparison&hl=en

We've been over this before:

The advantage of pushrod engines is the size of the whole package (no sexual innuendo intended). Because the camshaft is between the cylinder banks instead of on top of each row of cylinders, pushrod engines are shorter and narrower than OHC engines of the same displacement.

Because they're shorter and narrower than OHC engines of the same displacement, larger displacement pushrod engines can be used. Thus, the 6.0 liter LS2 takes up less space than the 4.6 liter DOHC Northstar V8, or BMW, Audi, Ford, or Infiniti's 4.5 liter OHC V8s. GM's pushrod V6s are also generally smaller than the 3-3.6 liter OHC V6 engines you can get.

So even though the pushrod's 2 heads can't breathe as well as a 3 head SOHC engine or a 4 or 5 head DOHC engine and it can't rev as high, it's got lots of extra cylinder space to compensate.

Then, GM can take advantage of its bigger torque output from larger size and make the gearing a little taller. That offsets the extra gas consumed by the larger engine to balance out fuel economy.

Would a 3.5 liter DOHC V6 outperform the 3.5 liter pushrod V6 in the Malibu? Yes... but you could fit 3.9 liter pushrod V6, maybe larger, into the Malibu's engine compartment. You couldn't fit a much bigger DOHC engine in there. (EDIT: in fact, you may not be able to fit a 3.5 liter DOHC V6 into the Malibu's engine compartment, period. I don't know.)

Would a 6.0 liter high performance DOHC V8 outperform the 6.0 liter pushrod V8 LS2 in the Corvette? Yes... but it probably wouldn't fit into a stock Corvette. If you could fit that 6.0 liter DOHC V8 in the Corvette, you could probably also put a beastly 8 liter pushrod V8 or maybe a 10 liter pushrod V10 in there... and while neither would perform as well as an 8 liter DOHC V8 or a 10 liter DOHC V10, they would trounce the 6.0 liter DOHC V8.

Etc... etc... etc...

Not to say that pushrods are always better. They aren't. And for both high performance and 'fun factor' reasons, having a really high RPM range is a good thing and pushrods can't deliver.

And from the next user down,

As I am sure you know, there are three ways to make power. More air(and thus fuel), better thermal efficiency, and better mechanical efficiency.

There are several ways of gettimg more air. An engine will always hold the same VOLUME of air. What you have to add is MASS(which is why I hate the term, volumetric efficiency). Bigger cylinders, bigger valves, more valves, denser air through compressors, and more RPMs are all ways of moving more air through the engine.

Hp/l only looks ar how much horsepower you are making based on cylinder size. Horsepower is a measurement over time. Cylinder size is a static measurement. I am sure you see the problem already.

Also, larger or mroe cylinders generally add to engine size, but not much to weight. But you also have to consider that engine material, number of valves, valvetrail configuration, etc., all also contibute to size and weight.

This is the reason that the 7 liter LS7 can be the same size and weight as the 3.5 liter VQ35, or the 3.9 liter V6 can be about the same size and weight as Hondas 2 liter I4.

I'm trying to verify thos elast two claims. Well, the penultimate one at least.

You know, there is not a lot of this type of information floating around on the internet. The closest I've come is yet another forum that says that the VQ35 weighs about 420 lbs dressed. (http://www.rx8club.com/showthread.php?p=531956#post531956)

WOW--get a load of this picture. It may be the one neanderthal was looking for, but its the ford OHV 5.0 (302) compared to the DOHC 4.6.

 

[neanderthal]

thats the pic right there.

huge difference between the DOHC engine and the OHV engine.

now dont get me wrong, you will not find me knowcking the "modern" engine as it will always produce better numbers per liter and so on, flow better (you can use multiple valves) usually rev higher etc etc etc, but when it comes to packaging, they are a lost cause.

 

[JNasty4G63]

Well, there is some info there. I still have hesitation about the cost you found for the LS7 on that site. Yes, it says it will cost $17k. But, it also says that the engine is only going to be available on a limited basis. So, its not exactly like its going to just be in a GMPP catalog for order. Things always cost more in limited basis.

Like I said before, its a fantastic motor, and probably one of the best V8 engines ever. But, I still think $17k is WAAAAAAYY too much for what you get performance-wise. As a package, its great. But, if all you want is power from a V8, just build an LS1-2.

This is the other thing I have problems with from your last post. It was a quote from who knows where......

Would a 6.0 liter high performance DOHC V8 outperform the 6.0 liter pushrod V8 LS2 in the Corvette? Yes... but it probably wouldn't fit into a stock Corvette. If you could fit that 6.0 liter DOHC V8 in the Corvette, you could probably also put a beastly 8 liter pushrod V8 or maybe a 10 liter pushrod V10 in there... and while neither would perform as well as an 8 liter DOHC V8 or a 10 liter DOHC V10, they would trounce the 6.0 liter DOHC V8.

That sounds all well and good. But, it seems many people have forgotten the LT5 in the old ZR1. That was a 400hp 350ci DOHC V8, and it fit just fine in the Vette. That was 400hp back in the early 90's!!! Fit just fine back then. Why all of a sudden would it not????

I understand that a DOHC engine isn't exactly small. But, I've seen many DOHC V6 engines out of cars (VG30, VQ35). And, I've seen many OHV V8 engines out of cars (LT1, LS1, LS2). And while the DOHC engines aren't exactly small, neither one is giant ammounts bigger or smaller than the other.

I'd also still like to know actual figures on actual AMG engines. I still have problems believing that one for a street car could cost anywhere close to $50k. Like I said, maybe $30k for the V12-TT in the new 65s, but nowhere near $50k.

Hilg

 

[TheCracker]

Heres a couple of links to American Speeds web site, they build high-end Chevy engines for the Ultima 640R etc - they might help with your discussion

http://www.amerspeed.com/cgi-bin/showenginetypes.cgi

http://www.amerspeed.com/cgi-bin/showultimaengines.cgi

 

[JNasty4G63]

Well, thats a little help. In that first link, where they list just base engines, not Ultima specific ones, you can get a 427ci with up to 600hp for $10k. Thats more like what I'm thinking. Its still a lot of $$$ for an engine. But fully assembled, dyno'd, and ready to roll, its not bad.

I know of 2 people with F-bodys here in Omaha that have LS1s stroked out to 383ci, and putting out well over 475hp to the wheels each. And neither of them spent more than $5k to get that. Like I said, I think the LS7 is a great engine, especially as a factory offering. And, I'm sure it will show up in some sweet street rods. But, for $17k, thats just not very much engine for your dollar.

Hilg

 

[skicrush]

That quote came from some GM inside news forum--the link was above the two quotes, but they were guys like us, discussing things on a forum. But that quote captures the esssence of what I was saying.

You have a good point with the ZR-1--somehow they managed to cram it in there, which is an engineering feat in itself. But the issue has always been cost--it cost more than the pushrod engine. HOWEVER, a lot of that cost may have been excessive costs because of the uniqueness of the platform, and its difference from both the normal vette engines, as well as the truck engines--WAY fewer common parts.

But in any case, it seems that the quote is exactly right. That same old 350 block is now a 427 (outta the same block), and while they could still make the ZR-1 a 427 (and probably get Blue Devil 600-700 hp out of it), assuming the ZR-1 motor would fit in a new vette, the cost due to differences and development costs would put it out of the market (again). More than the supercharger option would, with similar benefits.

And, I'm sure you can build an engine that is much smaller and puts out more power than the LS7--the LS7 puts out more power than the LS7 puts out. I'm just curious what kind of mielage they get in their cars? Chevy has to meet some pretty strict requirements.

 

[JNasty4G63]

But in any case, it seems that the quote is exactly right. That same old 350 block is now a 427 (outta the same block), and while they could still make the ZR-1 a 427 (and probably get Blue Devil 600-700 hp out of it), assuming the ZR-1 motor would fit in a new vette, the cost due to differences and development costs would put it out of the market (again). More than the supercharger option would, with similar benefits.

See, I guess thats my point right there. Again, while I don't doubt the ability of the LS7, its just waaaay to expensive for what you get for $17k. If all you want is big power, an LS7 crate motor is not the right start. Limited run engines are never cheap, so its not like Chevy is the only one charging a lot for an engine. But, I can think of many other things to do with $17k to make a Vette or F-body fast.

Hilg

 

[skicrush]

See, I guess thats my point right there. Again, while I don't doubt the ability of the LS7, its just waaaay to expensive for what you get for $17k. If all you want is big power, an LS7 crate motor is not the right start. Limited run engines are never cheap, so its not like Chevy is the only one charging a lot for an engine. But, I can think of many other things to do with $17k to make a Vette or F-body fast.

Hilg

Well, sure, lots of people are doing all kinds of things to LS2s (or even LS1s) to get them up into the LS7 ballpark, and it ALL costs less. But they're approximating the LS7 (boring out to a 383 or more--there are a couple bored out 427s around), and you're at the ragged edge of things, getting 10 mpg or so. Start with the LS7, and then do your magic that cares not about fuel economy, and you're at a very scary hp number.

HEY!! Has anyone noticed the "Buy GM LS7 Crate Engines" link at the bottom of the page? SO HELPFUL!!

LS7 Crate Engine Small Block 17802397 Coming Fall of 2005
Click here for: Warranty info, Start Up Instructions
Availability: This engine will immediately backorder,scheduled release date not yet available.


SKU: 17802397
RETAIL: $19,865.00
PRICE: $13,595.00

"RETAIL" looks a little high, but their price isn't bad at all!

 

[neanderthal]

....And, I'm sure you can build an engine that is much smaller and puts out more power than the LS7--the LS7 puts out more power than the LS7 puts out. I'm just curious what kind of mielage they get in their cars? Chevy has to meet some pretty strict requirements.

AMG recently debuted an engine smaller (6.3 liters) than the LS7 but with bigger numbers. story here

 

[skicrush]

They are sure full of themselves, aren't they?

Mercedes-AMG has taken a completely new departure: the new AMG 6.3-litre V8 engine is the first in the world to combine the high-revving concept with a large displacement. Developed entirely by AMG, this high-performance engine has a displacement of 6.3 litres and generates an output of 375 kW/510 hp at 6800 rpm, plus a maximum torque of 630 Newton metres, which makes the new power pack by AMG the world’s most powerful naturally aspirated eight-cylinder production engine. Thanks to its large displacement, the V8 by AMG develops around 20 percent more torque than comparable naturally aspirated engines in this performance class.

The high expectations of AMG customers and the impressive history of AMG eight-cylinder engines were both an incentive and an obligation for the engineers and product planners at Mercedes-AMG GmbH to come up with a superlative new V8 power unit. A mere glance at the key technical data shows that this has been achieved: from a displacement of 6208 cubic centimetres, the AMG V8 aluminium engine develops a peak output 375 kW/510 hp at 6800 rpm and a maximum torque of 630 Newton metres which is available from 5200 rpm. The maximum engine speed is 7200 rpm.

"Thanks to its large displacement, the V8 by AMG develops around 20 percent more torque than comparable naturally aspirated engines in this performance class.... The new AMG V8 already delivers 500 Newton metres to the crankshaft at 2000 rpm, while the maximum of 630 Newton metres is on tap at 5200 rpm – more than any other naturally aspirated engine in this output and displacement class." I wonder what class they're talking about? How narrowly are they defining this? Anything NOT BIGGER than 6.3, regardless of anything else? 630 newton meter = 464.6641528 pound foot.

"Mercedes-AMG has taken a completely new departure: the new AMG 6.3-litre V8 engine is the first in the world to combine the high-revving concept with a large displacement....The maximum engine speed is 7200 rpm." Yeah, folks, REAL original. It just makes them sound like pompous A-holes. They couldn't do any better than that with DOHC and 32 valves? Sure makes the LS7 look good!

 

[Dave A]

Stop arguing and appreciate the unique charecteristics of each engine for what they are.

 

[skicrush]

Stop arguing and appreciate the unique charecteristics of each engine for what they are.

I appreciate it plenty. I think its great. I just think they're trying a little too hard to blow their own horn, a little too loudly. It's hardly "first ever" when a similar sized engine has a similarly high redline, is much lower tech, and debuted 8 months ago.