RE: Camaro heads for 500bhp

[qube_TA]

havoc said:

The main benefits of a smaller, higher bhp/litre engine are:-

- Packaging - the car can be made smaller, and hence lighter...and it becomes a virtuous circle of reduced weight and better performance. This is even more important when making a 'hot' version of a mundane car, as the engine bay is often quite small and restricted.
- Reduced thermal losses, and hence greater efficiency*.
- (Often) Weight.

• Not always that simple - large, lazy, torquey yank pushrod lumps can have decent fuel economy through longer gearing such that at cruising speeds they're at ultra-low rpm...feasible only because of the much greater torque. Blunts the performance slightly in the process though...although with say 400bhp you don't notice that much!

Engines with a higher BHP/Ltr have to have more cams & valves, blowers etc, they're much more complicated thus are physically bigger and heavier, usually with a higher centre of gravity and poorer MPG. The GM LSx V8's despite having a large displacement are physically quite small and light, Ferrari engines are huge in comparison.

[havoc]

qube_TA said:

Engines with a higher BHP/Ltr have to have more cams & valves, blowers etc, they're much more complicated thus are physically bigger and heavier, usually with a higher centre of gravity and poorer MPG. The GM LSx V8's despite having a large displacement are physically quite small and light, Ferrari engines are huge in comparison.

Rover V8 versus an old-M3 engine or a high-output VTEC engine (B18C, H22A, K20A, F20C all near or >200bhp). Which is bigger overall?

Yes the pushrod V8 will have a lower c-o-g, but it's not necessarily lighter, despite all the head-work on the advanced engine.

Oh...and think about the width of a car with a v8 in it...aside from the car needing to be wider, it potentially affects the suspension location / geometry too!!!


If big ol' pushrod V8's were that good a solution, why have Europe and Japan shied away from them en-masse???

[RichardD]

havoc said:

...
If big ol' pushrod V8's were that good a solution, why have Europe and Japan shied away from them en-masse???

Because they need to be different? Generally car companies stick to their roots.

BMW's have always been complex engineering. If the new V8 M3 had an engine similar to a GM LS2 then there would be complaints of not following on from previous models, why is the car so expensive when it has such a simple engine.

Going for (an arguably over complex) solution IMO adds prestige and the ability to charge more money for this complexity. After all car makers are businesses and profit is why cars are made in the first place.

[wheeljack]

havoc said:

Rover V8 versus an old-M3 engine or a high-output VTEC engine (B18C, H22A, K20A, F20C all near or >200bhp). Which is bigger overall?

Yes the pushrod V8 will have a lower c-o-g, but it's not necessarily lighter, despite all the head-work on the advanced engine.

Oh...and think about the width of a car with a v8 in it...aside from the car needing to be wider, it potentially affects the suspension location / geometry too!!!


If big ol' pushrod V8's were that good a solution, why have Europe and Japan shied away from them en-masse???

Martin

Be fair! You can't compare that dinosaur Rover V8 to modern Honda or BMW units. (Actually your choice of BMW S54 I6 was a bad one because with it's cast-iron block it was probably heavier than the Rover!) If the Rover V8 "concept" was updated, with latest knowledge and techniques at 4.0 litre, 300bhp would have been achievable with engine mass IMO fairly comparable to a high-tune aluminium 3.0 DOHC I6.

Which ever way you look at it there is a case for any design and are sometimes more compelling depending on circumstances (Pushrods on Vee-engines make far more sense than on inline engines). Blanket 4-valve DOHC pentroof design is not always necessary as Honda have proved with their SOHC 24V V6's and their little I4 with SOHC 8V with dual spark plugs.

[Code Monkey]

mackie1 said:

80bhp/l from a 2 valve engine is great. Specific output is pretty meaningless anyway. There's more than one way to crack a nut. See David Yu's column about the Z06 engine vs the F430.

Yup with a 2 valve head as well it keeps the overall volume of the engine down, hence you get the lower nose specially when you look at the likes of the vette.

swept volume is only part of the engine size, and packaging is just as important as getting a quart out of a pint pot.

[anonymous-user]

Code Monkey said:

Yup with a 2 valve head as well it keeps the overall volume of the engine down, hence you get the lower nose specially when you look at the likes of the vette.

swept volume is only part of the engine size, and packaging is just as important as getting a quart out of a pint pot.

At last someone on this thread who knows what he's talking about rather than spouting the usual drivel about "all American cars/engines are rubbish".

Many USA V6s and V8s are designed to give economical cruising over long distances in an unstressed fashion and with long service intervals. Jap/Euro rev-boxes have different strengths and weaknesses. It is idiotic to suggest one category is better than the other; they're just different.

Thank you code monkey!!

[havoc]

wheeljack said:

Which ever way you look at it there is a case for any design and are sometimes more compelling depending on circumstances (Pushrods on Vee-engines make far more sense than on inline engines). Blanket 4-valve DOHC pentroof design is not always necessary as Honda have proved with their SOHC 24V V6's and their little I4 with SOHC 8V with dual spark plugs.

Oh I agree.

I was trying to point out the advantages of a 4v/cyl DOHC variable-valve engine vs a 2v/cyl pushrod, I wasn't trying to say they were better.
As I said earlier, I've a lot of time for the LS-series and this new engine looks quite a corker too...(IMHO some of the best performance engines around at the moment are the better LS's and the new AMG 6.3).

What I didn't say was that often the packaging benefit is forced on a manufacturer by the pre-existing platform (esp. Jap and Euro mfrs), and given a free choice (oh and no tax penalties) many probably WOULD go for cubes...

[Miguel]

havoc said:

qube_TA said:

Engines with a higher BHP/Ltr have to have more cams & valves, blowers etc, they're much more complicated thus are physically bigger and heavier, usually with a higher centre of gravity and poorer MPG. The GM LSx V8's despite having a large displacement are physically quite small and light, Ferrari engines are huge in comparison.

Rover V8 versus an old-M3 engine or a high-output VTEC engine (B18C, H22A, K20A, F20C all near or >200bhp). Which is bigger overall?

Hi Martin. I enjoy our debates, but that's an irrelevant comparison. Horses for courses, apples and oranges, and all that. I don't see a car manufacturer debating whether to put a 2 L Honda VTEC or 4 L Rover V8 in the same car even if they both produce the same power. The power delivery and torque outputs will make them completely different driving experiences.

In some cases, it's a matter of what their clients expect. In others, it's also a matter of what's appropriate for the type of car. For example, the current Mercedes S500 has a 5.5 L V8. It's DOHC and has 4 valves per cylinder, but it produces about the same specific power as the pushrod Chrysler 6.1 V8. Hey, Ferrari had a 3.5 L V8 a few years back that produced about the same 380 some hp as the current S500, but somehow I don't feel it would be appropriate for that car. Yes, it's an extreme example, but it makes the point.

havoc said:

Yes the pushrod V8 will have a lower c-o-g, but it's not necessarily lighter, despite all the head-work on the advanced engine.

Not necessarily, but you did pick the wrong example of the V8 with the Rover if you want to say it's not that light. According to what I've read, the original Buick/Oldsmobile 215 cu in V8 weighed about the same as the engine in your S2000, though the latest Rover 4.6 is somewhat heavier due to the reinforced block. Honda VTEC 4 cylinder engines are not as light as you may think. And the M3's straight 6, given its DOHC head and iron block must be incredibly heavy. American pushrod V8's are rather light, especially the all-aluminum versions. They are particularly light given their displacement and cost. Keep in mind that the current LS Chevy engine has 7 liter potential, which you'll find in the Z06. Externally, all LS engines are of the same dimensions.

havoc said:

Oh...and think about the width of a car with a v8 in it...aside from the car needing to be wider, it potentially affects the suspension location / geometry too!!!

Again, comparing V8's to straight fours or sixes is completely pointless. Yanks love their V8's. Brits are married to straight sixes. Honda lovers love their fours.

havoc said:

If big ol' pushrod V8's were that good a solution, why have Europe and Japan shied away from them en-masse???

Again, they're a solution. They're the right solution where appropriate. Americans love their pushrod V8's because they grew up on them. Why? Because when you have wide-open roads, huge cars, and unbelievably cheap fuel, that's what you get. European V8's have always been high-tech because they're used in their more high-end cars. There's no history of cheap V8's in Europe or Asia, therefore they're not as relevant. The closest thing to cheap V8s in Europe would be Rovers in England or some Opels in the early 70's that used the Chevy 327, but while they were cheaper than equivalent Jaguars or Mercedes models, they were not cars that high-school students would've bought.

Miguel

[Miguel]

JulesV said:

mackie1 said:

volvos60s60 said:

Are we talking US gallons or imperial gallons here when discussing mpg figures realised? 1 US gallon = 0.83 imperial gallons, so 27 mpg (US) = 22.5 mpg (UK)

Are you sure? By my calcs 27 miles per US gallon equals 7.1 miles per litre. Times that by 4.55 to get miles per imperial gallon and that's 32.4 mpg.

It was 24 and a bit US gallons which I worked out was about 27 UK mpg. I stand to be corrected however.

It's actually closer to 28.8 UK mpg. What's interesting is that in my 2001 5-speed Mazda MX5 (1.8 L 142 hp, 4.3 rear end), I've never gotten more than 25 mpg (US) in mostly city driving nor more than 28.5 mpg with a lot of highway miles. In UK gallons, that's about 30 and 34.2 respectively. A small engine having to work hard by revving high, using short gearing is not the greatest recipe for fuel economy, though it's good for fun. Most people here in the land of 6000 lb SUV's look at my car and just assume that it gets much better mileage than it actually does due to the car's and its engine's small size.

Miguel

[havoc]

Hi back Miguel,

I think our last two posts just missed each other...probably already responded to many of your points.

Oh...agreed on the Buick/Rover V8 (both old and light), but couldn't think of another low-tech V8 in widespread use in the UK...


I think much of it IS cultural (either in-nation or in-brand), and some of the unusual transplants have come up with surprisingly good results:-
- LS2 in an RX7
- LS? in an MX5 (hell of a plumbing exercise though, by all accounts!)
- RB26DETT (Skyline GTR lump) in a Ford P100 ( - a Sierra-based flatbed pickup...made a very capable drift car in the UK D1 championship)
- B16_ (Civic VTi engine) or B18C ('teg engine) in a Mini

[Miguel]

havoc said:

Hi back Miguel,

I think our last two posts just missed each other...probably already responded to many of your points.

Oh...agreed on the Buick/Rover V8 (both old and light), but couldn't think of another low-tech V8 in widespread use in the UK...


I think much of it IS cultural (either in-nation or in-brand), and some of the unusual transplants have come up with surprisingly good results:-
- LS2 in an RX7
- LS? in an MX5 (hell of a plumbing exercise though, by all accounts!)
- RB26DETT (Skyline GTR lump) in a Ford P100 ( - a Sierra-based flatbed pickup...made a very capable drift car in the UK D1 championship)
- B16_ (Civic VTi engine) or B18C ('teg engine) in a Mini

Doh!!! Sorry, Martin. You're right. I was in and out of the house and must've missed it. As for the above conversions, I've heard of the LS engines in the RX7, as well as a 944. I've seen one or two MX5's on the web with an LS engine, though quite a few here in the US have had the more compact Ford 302 conversion done. I think that's a bit over the top. I'd prefer a Ford Duratec 3.0 V6. Mazda made such a prototype. That would be plenty for my MX5. One PH'er around here has or had a P100 with a Rover V8, I believe. I'd never heard of the P100 before seeing his profile a few days ago, BTW. As for the VTEC conversions in the original Mini, there's one or two companies here in the US that do those, as well. I think they're fantastic.

Regards,

Miguel

[Spekdah-S2K]

Thanks for all the replies :-) I learned something today, which is a good thing to enjoy since one day, i'm sure it will start to go goes backwards.

[drivin_me_nuts]

What is the market for this type of car. Middle aged? early twenties? aspirational? Stateside, what other cars would someone looking at this be typically looking at by way of 'competition'. I am really curious to know if cars like this are perceived to be competitors to European models or is it typically for the homegrown audience?

Edited by drivin_me_nuts on Monday 10th September 03:33

[Marquis_Rex]

Jack_and_MLE said:

6.2 ltr and 500bhp not so efficient really, just about 80bhp per litre could do better compare to an European engine

Yes absolutely terrible.It must be due to the pushrods and 2 valves/cylinder Probably because it's American.
Just like a BMW S62 M5 V8 engine- quad cams, dual vanos , twin air boxes and port throttles for a whopping 80 Bhp/litre.
Or the Porsche 928 GTS, quad cams, dual resonance intake manifold, ceramic lined exhaust ports, 4 valves per cylinder, sodium cooled valves and a whopping 64 Bhp/litre.

Edited by Marquis_Rex on Thursday 13th September 07:40

[AdeTuono]

Marquis_Rex said:

Jack_and_MLE said:

6.2 ltr and 500bhp not so efficient really, just about 80bhp per litre could do better compare to an European engine

Yes absolutely terrible.It must be due to the pushrods and 2 valves/cylinder Probably because it's American.
Just like a BMW S62 M5 V8 engine- quad cams, dual vanos , twin air boxes and port throttles for a whopping 80 Bhp/litre.
Or the Porsche 928 GTS, quad cams, dual resonance intake manifold, ceramic lined exhaust ports, 4 valves per cylinder, sodium cooled valves and a whopping 64 Bhp/litre.

Edited by Marquis_Rex on Thursday 13th September 07:40

[Miguel]

Marquis_Rex said:

Jack_and_MLE said:

6.2 ltr and 500bhp not so efficient really, just about 80bhp per litre could do better compare to an European engine

Yes absolutely terrible.It must be due to the pushrods and 2 valves/cylinder Probably because it's American.
Just like a BMW S62 M5 V8 engine- quad cams, dual vanos , twin air boxes and port throttles for a whopping 80 Bhp/litre.
Or the Porsche 928 GTS, quad cams, dual resonance intake manifold, ceramic lined exhaust ports, 4 valves per cylinder, sodium cooled valves and a whopping 64 Bhp/litre.

Edited by Marquis_Rex on Thursday 13th September 07:40

But those are old European engines. How about comparing it to a modern one? The current Mercedes 500 models have 5.5 L of displacement and put out around 382 hp. Specific output is around 70 hp/L, but since it's European and has DOHC and four valves per cylinder, no one ever criticizes it for that. Considering the type of cars that engine is used in, faulting it for low specific power would be ridiculous, but whenever an American engine is mentioned, it always happens.

Miguel

[AdeTuono]

Miguel said:

Marquis_Rex said:

Jack_and_MLE said:

6.2 ltr and 500bhp not so efficient really, just about 80bhp per litre could do better compare to an European engine

Yes absolutely terrible.It must be due to the pushrods and 2 valves/cylinder Probably because it's American.
Just like a BMW S62 M5 V8 engine- quad cams, dual vanos , twin air boxes and port throttles for a whopping 80 Bhp/litre.
Or the Porsche 928 GTS, quad cams, dual resonance intake manifold, ceramic lined exhaust ports, 4 valves per cylinder, sodium cooled valves and a whopping 64 Bhp/litre.

Edited by Marquis_Rex on Thursday 13th September 07:40

But those are old European engines. How about comparing it to a modern one? The current Mercedes 500 models have 5.5 L of displacement and put out around 382 hp. Specific output is around 70 hp/L, but since it's European and has DOHC and four valves per cylinder, no one ever criticizes it for that. Considering the type of cars that engine is used in, faulting it for low specific power would be ridiculous, but whenever an American engine is mentioned, it always happens.

Miguel

I think that was Marquis Rex's point...

[Marquis_Rex]

AdeTuono said:

Miguel said:

Marquis_Rex said:

Jack_and_MLE said:

6.2 ltr and 500bhp not so efficient really, just about 80bhp per litre could do better compare to an European engine

Yes absolutely terrible.It must be due to the pushrods and 2 valves/cylinder Probably because it's American.
Just like a BMW S62 M5 V8 engine- quad cams, dual vanos , twin air boxes and port throttles for a whopping 80 Bhp/litre.
Or the Porsche 928 GTS, quad cams, dual resonance intake manifold, ceramic lined exhaust ports, 4 valves per cylinder, sodium cooled valves and a whopping 64 Bhp/litre.

Edited by Marquis_Rex on Thursday 13th September 07:40

But those are old European engines. How about comparing it to a modern one? The current Mercedes 500 models have 5.5 L of displacement and put out around 382 hp. Specific output is around 70 hp/L, but since it's European and has DOHC and four valves per cylinder, no one ever criticizes it for that. Considering the type of cars that engine is used in, faulting it for low specific power would be ridiculous, but whenever an American engine is mentioned, it always happens.

Miguel

I think that was Marquis Rex's point...

Thank you
At least someone understands irony

[havoc]

Marquis_Rex said:

At least someone understands irony

Isn't that the stuff that old-fashioned engine-blocks are made from?!?






OK, OK,

[Marquis_Rex]

Edited by Marquis_Rex on Friday 14th September 10:40