There is no replacement for displacement

[Captain Muppet]

300bhp/ton said:

Captain Muppet said:

It is possible to build an engine with a given limit of capacity that is better than an engine of equal or greater capacity that has a lower level of technology. This disproves that there is no replacement for displacement.

Curious, but how does it disprove it?

I just don't understand how this isn't simply an alternative, rather an replacement?

I would like to continue this discussion with either an alternative 300bhp/ton or a replacement 300bhp/ton.

[Captain Muppet]

minime68 said:

But the topic is about displacement not bigger turbos. You can say " well a turbo can replace displacement". No it cant. Lets say with a smaller FI engine, you make the same power as bigger N/A engine. The NA engine will have a much better power curve. I'm too lazy to write a whole write-up on it so ill copy and paste this which explains what I'm trying to say.

Cool, lets hope the second sentence of your cut&paste doesn't massively undermine your argument by suggesting there is a replacement for displacement...

minime68 said:

"There is no replacement for displacement. Let me correct myself: there is one: Cubic dollars.

[Dr Interceptor]

300bhp/ton said:

Captain Muppet said:

It is possible to build an engine with a given limit of capacity that is better than an engine of equal or greater capacity that has a lower level of technology. This disproves that there is no replacement for displacement.

Curious, but how does it disprove it?

I just don't understand how this isn't simply an alternative, rather an replacement?

Hmmmmmmmm........

Taking the old Supercharged R53 Cooper S as an example, it had a relatively low tech Tritec engine, made in Brazil. Cast iron block, SOHC - pretty low tech. The facelift car made 170bhp, pretty decent for a 1.6l hot hatch, but the engine was easily tweaked - a 17% reduction pulley, better intercooler, and an ignition upgrade would see 220bhp, airbox and exhaust 230bhp, then add a cam, head, injectors and you might be pushing 250bhp. There are plenty of R53s out there running 260/270bhp, many cars with more than that.

So there you have a relatively low tech engine, which with a load of parts thrown at it is capable of putting out nigh on 300bhp. Still keeping it a 1.6.

That power figure is a direct comparison for my E430 Merc, 4.3l V8 which puts out around 300bhp.

However, the way the two engines go about achieving the power is totally different. The MINI is tuned to within an inch of its life - durability of the supercharger and other components will be compromised, and it will be louder than usual with different manifolds and exhaust. The Merc on the other hand was built to put out 300bhp all its life. It's done 140k miles now, and will do 250k miles easily.

So, you can make a low tech engine, built to a size, which offers a similar power figure to a larger displacement engine. But the bigger displacement engine will in most circumstances prove to be the more reliable unit for generating said power.

So I would say that tuning smaller engines is an alternative to displacement, but not a true replacement.

[minime68]

Dr Interceptor said:

So I would say that tuning smaller engines is an alternative to displacement, but not a true replacement.

Precisely. There's a reason you dont see high HP small displacement engines on lorries or heavy equipment. Can it be done? Yes, but at a MUCH higher cost. For example, look at the cost of an F1 engine compared to NASCAR. Why do you think they limit displacement on these engines?

[300bhp/ton]

Captain Muppet said:

300bhp/ton said:

Captain Muppet said:

It is possible to build an engine with a given limit of capacity that is better than an engine of equal or greater capacity that has a lower level of technology. This disproves that there is no replacement for displacement.

Curious, but how does it disprove it?

I just don't understand how this isn't simply an alternative, rather an replacement?

I would like to continue this discussion with either an alternative 300bhp/ton or a replacement 300bhp/ton.

I guess I must need English lessons. Sorry, not being difficult, I just don't get it.

[Dog Star]

cspan said:

There is a replacement for displacement - and that's forced induction, no? However, it is difficult to replicate that "big engine feel" (particularly in a relatively small bodied car) through other methods. Yes I guess at the root of it it's really just torque, response (and the noise), but...

I've recently changed from a MB SL500 which is a 5 litre V8 with 306bhp and (I think) 460nM torque. All fine and dandy.

However my new chariot is an SLK250CDi - a 2.2l 4 pot diseasel with twin turbos giving 204bhp and a quite humungous 500nM of torque. As far as I'm concerned this blows the "no substitute for cubes" mantra into the weeds. I love the power delivery (needs a zillion speed gearbox though), it feels like there is a lot of power and 90% of the time it is faster (or faster feeling at any rate) than the SL. As a bonus I get 63mpg commuting. Very clever.

IMO longevity is suspect though; I wouldn't want to own a five year old example.

[eliot]

Perhaps write into mythbusters and ask them to solve this conundrum.

[minime68]

Dog Star said:

I've recently changed from a MB SL500 which is a 5 litre V8 with 306bhp and (I think) 460nM torque. All fine and dandy.

However my new chariot is an SLK250CDi - a 2.2l 4 pot diseasel with twin turbos giving 204bhp and a quite humungous 500nM of torque. As far as I'm concerned this blows the "no substitute for cubes" mantra into the weeds. I love the power delivery (needs a zillion speed gearbox though), it feels like there is a lot of power and 90% of the time it is faster (or faster feeling at any rate) than the SL. As a bonus I get 63mpg commuting. Very clever.

IMO longevity is suspect though; I wouldn't want to own a five year old example.

It gets tricky when you compare two different designs and engine components. Especially when you compare diesel vs petrol.

[Captain Muppet]

300bhp/ton said:

Captain Muppet said:

300bhp/ton said:

Captain Muppet said:

It is possible to build an engine with a given limit of capacity that is better than an engine of equal or greater capacity that has a lower level of technology. This disproves that there is no replacement for displacement.

Curious, but how does it disprove it?

I just don't understand how this isn't simply an alternative, rather an replacement?

I would like to continue this discussion with either an alternative 300bhp/ton or a replacement 300bhp/ton.

I guess I must need English lessons. Sorry, not being difficult, I just don't get it.

al·ter·na·tive (ôl-tûrn-tv, l-)
n.
The choice between two mutually exclusive possibilities.

replacement [rɪˈpleɪsmənt]
n
a person or thing that replaces another.

An alternative to displacement is something that isn't displacement.
A replacement for displacement is something that isn't displacement.

I'm at my limit of language skills, at this point it'd be much easier for me to design and build you a pair of engines and take them to a dyno.

[minime68]

Captain Muppet said:

al·ter·na·tive (ôl-tûrn-tv, l-)
n.
The choice between two mutually exclusive possibilities.

replacement [rɪˈpleɪsmənt]
n
a person or thing that replaces another.

An alternative to displacement is something that isn't displacement.
A replacement for displacement is something that isn't displacement.

I'm at my limit of language skills, at this point it'd be much easier for me to design and build you a pair of engines and take them to a dyno.

So what you want us to discuss/compare is, for example:

Engine 1: 2.0L Turbo 4 Cylinder engine @300BHP?

Engine 2: 4.6.0L NA V8 @300BHP?

[Captain Muppet]

minime68 said:

It gets tricky when you compare two different designs and engine components. Especially when you compare diesel vs petrol.

Yes, it's much easier and simpler when you have two engines of identical physical geomtetry and identical displacement one of which produces more power and torque because it's internal friction has been reduced, or because it has a more sophisticated ECU map, or because of any of the other things you can do to improve it which aren't increasing the displacement.

Which isn't to say increasing the displacement doesn't also work, it just isn't the only thing that works.

[Captain Muppet]

minime68 said:

Captain Muppet said:

al·ter·na·tive (ôl-tûrn-tv, l-)
n.
The choice between two mutually exclusive possibilities.

replacement [rɪˈpleɪsmənt]
n
a person or thing that replaces another.

An alternative to displacement is something that isn't displacement.
A replacement for displacement is something that isn't displacement.

I'm at my limit of language skills, at this point it'd be much easier for me to design and build you a pair of engines and take them to a dyno.

So what you want us to discuss/compare is, for example:

Engine 1: 2.0L Turbo 4 Cylinder engine @300BHP?

Engine 2: 4.6.0L NA V8 @300BHP?

No, I'd be fine with you just reading the OP and having a little think about it.

From page 2:

Captain Muppet said:

Just for all those who missed it in the OP and started talking about highly tuned tiny engines not being as good as huge simple engines:

Captain Muppet said:

I know that someone is going to slag off tiny engines, and probably say something entirely valid like 160bhp 1.6 Vtecs don't have the same torque curve as a 160bhp 3.5 Rover V8. But in order for the cliché to be wrong we just have to imagine a 3.4litre engine that is not worse than the 3.5 litre one, and that's easy.

[300bhp/ton]

Captain Muppet said:

al·ter·na·tive (ôl-tûrn-tv, l-)
n.
The choice between two mutually exclusive possibilities.

replacement [rɪˈpleɪsmənt]
n
a person or thing that replaces another.

An alternative to displacement is something that isn't displacement.
A replacement for displacement is something that isn't displacement.

I'm at my limit of language skills, at this point it'd be much easier for me to design and build you a pair of engines and take them to a dyno.

I guess there is a degree of semantics going on.

But my take is, 'no replacement for displacement' simply means a small engine won't do this.

Which is generally true. Sure you can do many things to make a small engine perform better, but none of them will truly mimic the same power delivery of a large displacement n/a engine.

Every engine is more than just it's PEAK hp figure.

[Captain Muppet]

300bhp/ton said:

Captain Muppet said:

al·ter·na·tive (ôl-tûrn-tv, l-)
n.
The choice between two mutually exclusive possibilities.

replacement [rɪˈpleɪsmənt]
n
a person or thing that replaces another.

An alternative to displacement is something that isn't displacement.
A replacement for displacement is something that isn't displacement.

I'm at my limit of language skills, at this point it'd be much easier for me to design and build you a pair of engines and take them to a dyno.

I guess there is a degree of semantics going on.

But my take is, 'no replacement for displacement' simply means a small engine won't do this.

Which is generally true. Sure you can do many things to make a small engine perform better, but none of them will truly mimic the same power delivery of a large displacement n/a engine.

Every engine is more than just it's PEAK hp figure.

If your take on "no replacement for displacement" is that "a small engine won't do" then that is fine, because what this thread is about is what those words actually mean when placed in that order, rather than what that phrase stands for as a philosophy.

What if you take a 400bhp 7.2 litre NA V8, and make a fractionally shorter stroke and smaller bore 7.1 litre NA V8. If it is possible to get the same 400bhp (and torque curve) by improving things that aren't the displacement then you have replaced that displacement with engineering.

Hell a very lightly tuned 7.1 litre NA V8 might even sound, feel, look and taste the same as a 7.2 litre V8. You don't even have to change the cams, or timing, or exhaust to do it.

If Mythbusters want to pay for it I'm happy to do the work to disprove that there is "no replacement for displacement".

Again, this thread is about is what those words actually mean when placed in that order, rather than what that phrase stands for as a philosophy.

[300bhp/ton]

Captain Muppet said:

If your take on "no replacement for displacement" is that "a small engine won't do" then that is fine, because what this thread is about is what those words actually mean when placed in that order, rather than what that phrase stands for as a philosophy.

What if you take a 400bhp 7.2 litre NA V8, and make a fractionally shorter stroke and smaller bore 7.1 litre NA V8. If it is possible to get the same 400bhp (and torque curve) by improving things that aren't the displacement then you have replaced that displacement with engineering.

Hell a very lightly tuned 7.1 litre NA V8 might even sound, feel, look and taste the same as a 7.2 litre V8. You don't even have to change the cams, or timing, or exhaust to do it.

If Mythbusters want to pay for it I'm happy to do the work to disprove that there is "no replacement for displacement".

Again, this thread is about is what those words actually mean when placed in that order, rather than what that phrase stands for as a philosophy.

Well ok.

But aren't you also taking the phrase and altering the rules a little by saying you want to 'modify' a smaller engine to get the same result.

Even using your example by modding a 7.1 litre V8 and comparing to a 7.2 litre V8 the result is still being supplied by an engine with displacement.

In fact on simple fact value there is:

-engine with no displacement
-engine with displacement

Can you via anything make the first one do the same as the second without any displacement?

[Captain Muppet]

300bhp/ton said:

In fact on simple fact value there is:

-engine with no displacement
-engine with displacement

Can you via anything make the first one do the same as the second without any displacement?

I can make an electric motor generate any torque curve you want.

I could engineer an entire world without internal combustion of any kind. It'll come at the cost of quite a bit of money and social upheaval, but it's possible.

[TiMopar]

The physics involved are simple; to move big stuff around you need a big engine. If you want your farm truck to run 10sec quarter miles, add some nitrous to your big engine thus;
http://www.youtube.com/watch?v=_TAj-s7xmuk&lis...

[xRIEx]

Captain Muppet said:

To get 40% more power the displacement did not increase by 40%.

There is a replacement for displacement, it's called engineering.

I think the biggest problem with cliches is people misunderstanding what they actually mean (or meant in the first place) and using them out of context.

'Torque/power curve' has already been mentioned in this thread, so I'll leave that.

Of course, good engineering makes a fixed engine capacity produce more power (F1, LMP, etc.). However, working outside of fixed-capacity regulations, anything you can engineer for a {small size} engine you can also engineer for a {large size} engine. Throw £10m at the 3.4l engine to get {impressive number}BHP out of it? Cool. Now throw £10m at the Viper's V10 and let me know what the output is.

So fundamentally/theoretically there is no replacement for displacement - however, real world situations, specific applications and budgets mean there are more suitable real world alternatives.

[Captain Muppet]

xRIEx said:

Captain Muppet said:

To get 40% more power the displacement did not increase by 40%.

There is a replacement for displacement, it's called engineering.

I think the biggest problem with cliches is people misunderstanding what they actually mean (or meant in the first place) and using them out of context.

'Torque/power curve' has already been mentioned in this thread, so I'll leave that.

Of course, good engineering makes a fixed engine capacity produce more power (F1, LMP, etc.). However, working outside of fixed-capacity regulations, anything you can engineer for a {small size} engine you can also engineer for a {large size} engine. Throw £10m at the 3.4l engine to get {impressive number}BHP out of it? Cool. Now throw £10m at the Viper's V10 and let me know what the output is.

So fundamentally/theoretically there is no replacement for displacement - however, real world situations, specific applications and budgets mean there are more suitable real world alternatives.

Captain Muppet said:

this thread is about is what those words actually mean when placed in that order, rather than what that phrase stands for as a philosophy.