Displacement

[Demon-Xanth]

Originally posted by: Pacfanweb
What are you talking about? Greater displacement ALWAYS means greater weight, assuming you're talking about the engine itself.

Now if you're talking about not meaning the actual car weighs more, then yes.

But in general, you can't get a significant increase in displacement without an increase in the physical size of the engine, therefore it weighs more.

However, usually the weight gain is more than offset by the power gain. Built the same way, a larger engine will always make more power than a smaller one.
No replacement for displacement.

And I don't want to hear anyone saying "but what if you turbo/supercharge the smaller engine.
Well, first of all, I said "built the same way"...which means, apples-to-apples. Forced induction is simply a way of making the engine larger without actually increasing its displacement.
And if you're going to compare a forced-induction small engine to a large one, then the large one needs to be forced-induction, too...and it will make more power. Strictly talking about power potential, larger engines are always better.

To get back on topic, the Euros made smaller cars in general, and used smaller engines as a result.

Here's some fun little tid bits.
A 265 small block and a 400 small block weigh about the same.
The same is true in comparing the 5.7L LS1 to the 7L LS-7.
DOHC heads are massive compared to OHV heads.
It's not uncommon for a DOHC V6 to weigh 400LBs.
Examples:
Acura Legend V6: 491LBs
Renaul 2.8 V6: 375LBs
Toyota Camry V6: 469LBs for the iron block, 401LBs for the aluminum

These are all roughly 3L engines, and weigh comparable to GM's LS* engines that are roughly 6L.

If you compare the weight of a forced induction engine to a N/A, you need to also add in the extra plumbing such as intercoolers that the FI engine needs that the N/A doesn't.

 

[exdeath]

For the "boost is the replacement for displacement" guys, Vipers make almost 2000 HP with boost, probably even on 93 octane pump gas. Can a boosted Civic/Supra make that? A 2JZ needs 35+ psi and race gas or methanol and rev to 9 grand just to break 1000HP.

It's all about density*cubic inches per second of flow volume. Increasing density with boost increase heat and pressure which causes detonation. But when you run out of boost you can add more cubic inches all day without limit, and boost those cubes as well.

I guess the Europeons just haven't realized that yet, give 'em time.

 

[Demon-Xanth]

Originally posted by: exdeath
For the "boost is the replacement for displacement" guys, Vipers make almost 2000 HP with boost, probably even on 93 octane pump gas. Can a boosted Civic/Supra make that? A 2JZ needs 35+ psi and race gas or methanol and rev to 9 grand just to break 1000HP.

It's all about density*cubic inches per second of flow volume. Increasing density with boost increase heat and pressure which causes detonation. But when you run out of boost you can add more cubic inches all day without limit, and boost those cubes as well.

I guess the Europeons just haven't realized that yet, give 'em time.

I wouldn't say "without limit". DOHC doesn't help that engine though.

 

[GoatMonkey]

Originally posted by: Demon-Xanth

Originally posted by: Pacfanweb
What are you talking about? Greater displacement ALWAYS means greater weight, assuming you're talking about the engine itself.

Now if you're talking about not meaning the actual car weighs more, then yes.

But in general, you can't get a significant increase in displacement without an increase in the physical size of the engine, therefore it weighs more.

However, usually the weight gain is more than offset by the power gain. Built the same way, a larger engine will always make more power than a smaller one.
No replacement for displacement.

And I don't want to hear anyone saying "but what if you turbo/supercharge the smaller engine.
Well, first of all, I said "built the same way"...which means, apples-to-apples. Forced induction is simply a way of making the engine larger without actually increasing its displacement.
And if you're going to compare a forced-induction small engine to a large one, then the large one needs to be forced-induction, too...and it will make more power. Strictly talking about power potential, larger engines are always better.

To get back on topic, the Euros made smaller cars in general, and used smaller engines as a result.

Here's some fun little tid bits.
A 265 small block and a 400 small block weigh about the same.
The same is true in comparing the 5.7L LS1 to the 7L LS-7.
DOHC heads are massive compared to OHV heads.
It's not uncommon for a DOHC V6 to weigh 400LBs.
Examples:
Acura Legend V6: 491LBs
Renaul 2.8 V6: 375LBs
Toyota Camry V6: 469LBs for the iron block, 401LBs for the aluminum

These are all roughly 3L engines, and weigh comparable to GM's LS* engines that are roughly 6L.

If you compare the weight of a forced induction engine to a N/A, you need to also add in the extra plumbing such as intercoolers that the FI engine needs that the N/A doesn't.

It may be true that a 265 and 400 block weigh about the same, since they pretty much are the same except for the cylinders being bored out more. With the same thickness of metal in the block to scale up with cubic inches, it would weigh more.

I'm not arguing against you though. I actually agree with you on the rest of it.

Taking that 265 to 400 CI is roughly 1.5 times the displacement. If you did the same to one of those other 3.0L engines you'd get a 4.5L engine. Which is most likely not possible with the block they use. I'd expect they would have a hard time getting it any higher than 3.5L with the thicknesses normally used in a Japanese engine block wall. The Japanese engine would need an entirely different block to get that displacement increase.

 

[Demon-Xanth]

Originally posted by: GoatMonkey
It may be true that a 265 and 400 block weigh about the same, since they pretty much are the same except for the cylinders being bored out more. With the same thickness of metal in the block to scale up with cubic inches, it would weigh more.

I'm not arguing against you though. I actually agree with you on the rest of it.

Taking that 265 to 400 CI is roughly 1.5 times the displacement. If you did the same to one of those other 3.0L engines you'd get a 4.5L engine. Which is most likely not possible with the block they use. I'd expect they would have a hard time getting it any higher than 3.5L with the thicknesses normally used in a Japanese engine block wall. The Japanese engine would need an entirely different block to get that displacement increase.

My point being, is that people see a 3L V6 or 4L V8 w/ DOHC and assume that it's alot lighter than a 6L pushrod. When in many cases, it's the other way around. Going to DOHC or FI is adding weight just like adding displacement. It's just a difference of where you choose to add it. Believe it or not, but a Buick 215 V8 weighs LESS than a Honda 1.8L I-4. Most people don't consider all the size and weight of a DOHC head when considering engine weight, they look at displacement and think that weight and displacement are directly porportional regardless of the engine configuration. Granted, there are cases where it's true, there's alot of other factors involved.

 

[Pacfanweb]

Originally posted by: exdeath
For the "boost is the replacement for displacement" guys, Vipers make almost 2000 HP with boost, probably even on 93 octane pump gas. Can a boosted Civic/Supra make that? A 2JZ needs 35+ psi and race gas or methanol and rev to 9 grand just to break 1000HP.

Yeah, but you can make 1000 hp with a large cubic inch engine, RELIABLY, with NO boost.
So that's what you'd be comparing the Civic/Supras you mention to, not a really big-and-also-forced-induction engine.
That's where you get back to the old "no replacement for displacement" saying.

The larger engine ALWAYS has the most POTENTIAL power.

But it's a stone-cold fact that boost is essentially adding displacement. You are forcing more air through the engine than it could normally suck in on its own, without making it larger.

 

[Pacfanweb]

Originally posted by: Demon-Xanth
Here's some fun little tid bits.
A 265 small block and a 400 small block weigh about the same.

The BLOCKS are close in weight, but the 400 crank/rods/pistons/balancer assembly weighs more. 400's are externally balanced, and have a considerably larger harmonic balancer.

Otherwise, yeah, they're physically identical. BUT...the 400 does weigh a bit more. Not like 100 lbs more, but probably a good 40 lbs.
I get what you're saying, though.

 

[Pacfanweb]

Originally posted by: mariok2006The Bugatti Veyron does not really carry a lot of displacement when you take into account it has 16 cylinders. That is 0.5L per cylinder, the same as an M5 which has a low displacement V10. So in relation to the number of cylinders it isn't really "big displacement."

Sure it is. In fact, you have a big advantage, because the more cylinders you have, the more power strokes per revolution you get. Cubic inches is cubic inches. The engine with more cylinders will probably have an entirely different power curve, but it will still be better than a smaller engine with larger cylinders.

 

[mwmorph]

Originally posted by: Pacfanweb

Originally posted by: Demon-Xanth
Here's some fun little tid bits.
A 265 small block and a 400 small block weigh about the same.

The BLOCKS are close in weight, but the 400 crank/rods/pistons/balancer assembly weighs more. 400's are externally balanced, and have a considerably larger harmonic balancer.

Otherwise, yeah, they're physically identical. BUT...the 400 does weigh a bit more. Not like 100 lbs more, but probably a good 40 lbs.
I get what you're saying, though.

It's balanced out because the cylinder walls are thinner. It's bored out considerably for the 400.

 

[Pacfanweb]

Originally posted by: mwmorph

Originally posted by: Pacfanweb

Originally posted by: Demon-Xanth
Here's some fun little tid bits.
A 265 small block and a 400 small block weigh about the same.

The BLOCKS are close in weight, but the 400 crank/rods/pistons/balancer assembly weighs more. 400's are externally balanced, and have a considerably larger harmonic balancer.

Otherwise, yeah, they're physically identical. BUT...the 400 does weigh a bit more. Not like 100 lbs more, but probably a good 40 lbs.
I get what you're saying, though.

It's balanced out because the cylinder walls are thinner. It's bored out considerably for the 400.

Nah, the cylinders are siamesed, so there's meat in-between them, no water jacket. Plus, that doesn't balance out the weight of the rotating assembly. Crank and balancer weigh a good bit more.

All in all, though, it's not that much of a weight gain to get that many more cubes, but technically speaking, it is a gain.

 

[Zenmervolt]

Originally posted by: Pacfanweb

Originally posted by: mariok2006The Bugatti Veyron does not really carry a lot of displacement when you take into account it has 16 cylinders. That is 0.5L per cylinder, the same as an M5 which has a low displacement V10. So in relation to the number of cylinders it isn't really "big displacement."

Sure it is. In fact, you have a big advantage, because the more cylinders you have, the more power strokes per revolution you get. Cubic inches is cubic inches. The engine with more cylinders will probably have an entirely different power curve, but it will still be better than a smaller engine with larger cylinders.

I'm thinking that the internal friction would more than cancel the advantage of additional power pulses and that, aside from the technological crown from having a 16-cylinder engine, they would have been better off to make it a V12 or even a V8.

ZV

 

[Apex]

Originally posted by: Pacfanweb

Originally posted by: mwmorph

Originally posted by: Pacfanweb

Originally posted by: Demon-Xanth
Here's some fun little tid bits.
A 265 small block and a 400 small block weigh about the same.

The BLOCKS are close in weight, but the 400 crank/rods/pistons/balancer assembly weighs more. 400's are externally balanced, and have a considerably larger harmonic balancer.

Otherwise, yeah, they're physically identical. BUT...the 400 does weigh a bit more. Not like 100 lbs more, but probably a good 40 lbs.
I get what you're saying, though.

It's balanced out because the cylinder walls are thinner. It's bored out considerably for the 400.

Nah, the cylinders are siamesed, so there's meat in-between them, no water jacket. Plus, that doesn't balance out the weight of the rotating assembly. Crank and balancer weigh a good bit more.

All in all, though, it's not that much of a weight gain to get that many more cubes, but technically speaking, it is a gain.

This is what I mean. Often, bigger displacement engines of the same block will weigh almost exactly the same, since the bigger holes in the block are balanced out by the heavier pistons and such.

Also, if you take a look at many of these so called huge engines, they're really not that heavy, like in Demon-Xanth's examples. It's not just in theory, but in practice too.

The LS engine, in all its forms (up to even the rediculous Warhawk block based solutions), seems to only vary by a few lbs, fully dressed, regardless of displacement.

 

[thomsbrain]

Originally posted by: Demon-Xanth

Originally posted by: Pacfanweb
What are you talking about? Greater displacement ALWAYS means greater weight, assuming you're talking about the engine itself.

Now if you're talking about not meaning the actual car weighs more, then yes.

But in general, you can't get a significant increase in displacement without an increase in the physical size of the engine, therefore it weighs more.

However, usually the weight gain is more than offset by the power gain. Built the same way, a larger engine will always make more power than a smaller one.
No replacement for displacement.

And I don't want to hear anyone saying "but what if you turbo/supercharge the smaller engine.
Well, first of all, I said "built the same way"...which means, apples-to-apples. Forced induction is simply a way of making the engine larger without actually increasing its displacement.
And if you're going to compare a forced-induction small engine to a large one, then the large one needs to be forced-induction, too...and it will make more power. Strictly talking about power potential, larger engines are always better.

To get back on topic, the Euros made smaller cars in general, and used smaller engines as a result.

Here's some fun little tid bits.
A 265 small block and a 400 small block weigh about the same.
The same is true in comparing the 5.7L LS1 to the 7L LS-7.
DOHC heads are massive compared to OHV heads.
It's not uncommon for a DOHC V6 to weigh 400LBs.
Examples:
Acura Legend V6: 491LBs
Renaul 2.8 V6: 375LBs
Toyota Camry V6: 469LBs for the iron block, 401LBs for the aluminum

These are all roughly 3L engines, and weigh comparable to GM's LS* engines that are roughly 6L.

If you compare the weight of a forced induction engine to a N/A, you need to also add in the extra plumbing such as intercoolers that the FI engine needs that the N/A doesn't.

comparing old, cheap iron-block engines to the modern aluminum blocks in an $80K supercar isn't helping your case.

look at it this way: the original S2000 had a 2.0L that made 240 HP and cost ~$35K. The 3.0L V6 in my Accord from the same year makes the same max power, but costs 7K less, weighs 500 pounds more, and is more than 1 second slower to 60 miles per hour. which car is more fun? the S2000. and it is worth the price premium if your goal is to have fun and you like to DRIVE and not loaf.

 

[Apex]

Originally posted by: thomsbrain

Originally posted by: Demon-Xanth

Originally posted by: Pacfanweb
What are you talking about? Greater displacement ALWAYS means greater weight, assuming you're talking about the engine itself.

Now if you're talking about not meaning the actual car weighs more, then yes.

But in general, you can't get a significant increase in displacement without an increase in the physical size of the engine, therefore it weighs more.

However, usually the weight gain is more than offset by the power gain. Built the same way, a larger engine will always make more power than a smaller one.
No replacement for displacement.

And I don't want to hear anyone saying "but what if you turbo/supercharge the smaller engine.
Well, first of all, I said "built the same way"...which means, apples-to-apples. Forced induction is simply a way of making the engine larger without actually increasing its displacement.
And if you're going to compare a forced-induction small engine to a large one, then the large one needs to be forced-induction, too...and it will make more power. Strictly talking about power potential, larger engines are always better.

To get back on topic, the Euros made smaller cars in general, and used smaller engines as a result.

Here's some fun little tid bits.
A 265 small block and a 400 small block weigh about the same.
The same is true in comparing the 5.7L LS1 to the 7L LS-7.
DOHC heads are massive compared to OHV heads.
It's not uncommon for a DOHC V6 to weigh 400LBs.
Examples:
Acura Legend V6: 491LBs
Renaul 2.8 V6: 375LBs
Toyota Camry V6: 469LBs for the iron block, 401LBs for the aluminum

These are all roughly 3L engines, and weigh comparable to GM's LS* engines that are roughly 6L.

If you compare the weight of a forced induction engine to a N/A, you need to also add in the extra plumbing such as intercoolers that the FI engine needs that the N/A doesn't.

comparing old, cheap iron-block engines to the modern aluminum blocks in an $80K supercar isn't helping your case.

look at it this way: the original S2000 had a 2.0L that made 240 HP and cost ~$35K. The 3.0L V6 in my Accord from the same year makes the same max power, but costs 7K less, weighs 500 pounds more, and is more than 1 second slower to 60 miles per hour. which car is more fun? the S2000. and it is worth the price premium if your goal is to have fun and you like to DRIVE and not loaf.

How does that help your case? You didn't even mention engine weight at all.

BTW, the S2000's 2.0L 4 cyl is a rather portly 348 lbs. It's claim to fame is its stiffness and strength, but for its displacement, it's definitely not a lightweight.

 

[exdeath]

For all this talk of 'advanced technology' and 'advanced alloys like aluminum and titanium' and 'sophisticated engineering and lightweight engines', anyone else realize that the best of the best Japanese engines (3SGTE, 2JZGTE, SR20DET, RB26DETT) are all cast iron blocks? I wonder why...

 

[Demon-Xanth]

Originally posted by: thomsbrain
comparing old, cheap iron-block engines to the modern aluminum blocks in an $80K supercar isn't helping your case.

look at it this way: the original S2000 had a 2.0L that made 240 HP and cost ~$35K. The 3.0L V6 in my Accord from the same year makes the same max power, but costs 7K less, weighs 500 pounds more, and is more than 1 second slower to 60 miles per hour. which car is more fun? the S2000. and it is worth the price premium if your goal is to have fun and you like to DRIVE and not loaf.

Funny, I didn't know that the $30k Impala SS, Grand Prix GXP, and GTO were $80k supercars, thanks for letting me know! And your S2000 engine weighs in at 386LBs. Only about 60LBs lighter than the 5.3L, 5.7L, and 6.0L engines used in those $80,000 supercars that had $30,000 MSRPs on them.

Happy now?

 

[GoatMonkey]

look at it this way: the original S2000 had a 2.0L that made 240 HP and cost ~$35K. The 3.0L V6 in my Accord from the same year makes the same max power, but costs 7K less, weighs 500 pounds more, and is more than 1 second slower to 60 miles per hour. which car is more fun? the S2000. and it is worth the price premium if your goal is to have fun and you like to DRIVE and not loaf.

That's power to weight ratio that you're seeing there. If your Accord could shed that extra weight (and stop being a front drive boring Accord) it would be a different story.

That Accord engine would seem fantastic if they mounted it mid-engine style in a small lightweight sports car.

 

[Demon-Xanth]

Originally posted by: GoatMonkey
Accord engine would seem fantastic if they mounted it mid-engine style in a small lightweight sports car.

NSX anyone?

 

[GoatMonkey]

Originally posted by: Demon-Xanth

Originally posted by: GoatMonkey
Accord engine would seem fantastic if they mounted it mid-engine style in a small lightweight sports car.

NSX anyone?

Hah... I'm glad someone caught that.

 

[Demon-Xanth]

Originally posted by: GoatMonkey

Originally posted by: Demon-Xanth

Originally posted by: GoatMonkey
Accord engine would seem fantastic if they mounted it mid-engine style in a small lightweight sports car.

NSX anyone?

Hah... I'm glad someone caught that.

Does that mean that it's unfair that I compare the light powerful V8 family car engine to the heavy weak V6 $80k supercar engine?

OH SNAP!

 

[Pacfanweb]

Originally posted by: Apex

This is what I mean. Often, bigger displacement engines of the same block will weigh almost exactly the same, since the bigger holes in the block are balanced out by the heavier pistons and such.

Also, if you take a look at many of these so called huge engines, they're really not that heavy, like in Demon-Xanth's examples. It's not just in theory, but in practice too.

The LS engine, in all its forms (up to even the rediculous Warhawk block based solutions), seems to only vary by a few lbs, fully dressed, regardless of displacement.

Well, I guess I was just being technical.

What you say is true, though....take a Big Block Chevy, for example: You can get the Bowtie version of that block from Chevy. Or an aftermarket version, if you like.
Either one has considerable beef in the cylinder walls to allow extreme overbores.

So they start with the standard 427/454 bore of 4", and you can bore them to usually around 4.7".
Plus, they have room for longer stroke crankshafts. So you can easily make a 672" or bigger engine with these blocks. Yet externally, they are not one iota bigger than a plain Jane 396. One would probably weight 50lbs more than a standard 396 or 427, but the power gain would way more than offset that minor weight difference.
You can easily make over 1000 HP, normally aspirated and on pump gas with one of these.

A popular combo is to take an off-the-shelf 502 block, hone it to 4.5" bores (502 is slightly under that), get a 1/4" stroker crank which bolts right in and you have a 540. 750 streetabl HP available with this one, easily, and it'll live forever.

 

[Apex]

Originally posted by: Pacfanweb

Originally posted by: Apex

This is what I mean. Often, bigger displacement engines of the same block will weigh almost exactly the same, since the bigger holes in the block are balanced out by the heavier pistons and such.

Also, if you take a look at many of these so called huge engines, they're really not that heavy, like in Demon-Xanth's examples. It's not just in theory, but in practice too.

The LS engine, in all its forms (up to even the rediculous Warhawk block based solutions), seems to only vary by a few lbs, fully dressed, regardless of displacement.

Well, I guess I was just being technical.

What you say is true, though....take a Big Block Chevy, for example: You can get the Bowtie version of that block from Chevy. Or an aftermarket version, if you like.
Either one has considerable beef in the cylinder walls to allow extreme overbores.

So they start with the standard 427/454 bore of 4", and you can bore them to usually around 4.7".
Plus, they have room for longer stroke crankshafts. So you can easily make a 672" or bigger engine with these blocks. Yet externally, they are not one iota bigger than a plain Jane 396. One would probably weight 50lbs more than a standard 396 or 427, but the power gain would way more than offset that minor weight difference.
You can easily make over 1000 HP, normally aspirated and on pump gas with one of these.

A popular combo is to take an off-the-shelf 502 block, hone it to 4.5" bores (502 is slightly under that), get a 1/4" stroker crank which bolts right in and you have a 540. 750 streetabl HP available with this one, easily, and it'll live forever.

That's a very fair accessment. :beer:

 

[Summitdrinker]

ya, na, ya..the more cubic inch you get from the same block starts to shorten engine life after a certian point, esp if run at higher rpm and or high loads.

big block chevies were a odd motor, atleast they were 20 years ago, one will be powerful and long lived the next one is a dog that dies early

also take into the fact the bigger the cubic inch per cylinder the more ineffeicent it will be burning wise, plus pollution goes up

 

[exdeath]

Small displacement engines like Ferrari V8s are usually over square, bore > stroke.

Shorter stroke shorter deck height for mid engine packaging maybe? Less low end torque, but capable of higher revs due to less reciprocating acceleration/deceleration and piston velocities. Larger bore allows more/bigger valves for air flow. Over square engines are also supposed to be more reliable and have longer lifespans due to less piston travel per revolution (less friction wear) but I'd hardly say exotics are reliable.

I honestly don't know what the fascination is with revving an engine high to make power if you have to wait all day for it. I just like to blip the throttle off idle and GO, not put my foot to the floor and watch the tach take a leisurely walk to the red line.

I guess some cultures like to impose artificial limits on things to make their lives more challenging than they need to be

 

[Summitdrinker]

plus there is other wear too, crank bearing wear, you can only make those bearings so big in a given block

the more cubic inch you make out of that given block along with higher compression too put more load on the bearings

main bearings do wear out