The Difference Between......

[motorhead]

Originally posted by crisis
I think a better question is why doesnt anyone else?

yep its very strange - subaru's insider said this - the ultimate car comes with 4 wheel drive and a boxer engine so why doesn't anyone use it

[stenyak]

from what i've read, the best choice is the flat6, because it produces no vibrations (any flat engine is perfectly balanced in any situation, therefore there's no horizontal, vertical o transversal vibration). also, they allow a lower center of gravity in the car, which makes the handling better.
the next better engine is the inline 6 in terms of vibration (more explanations about inline 6). A v6 (60º o 90º) allows lower center of gravity than i6, however it produces some vibrations that need to be eliminated via a balancer shaft. (more explanations about v6).

about the question why nobody uses it, here you have it:
"they are too wide for good packaging, and is more expensive due to more parts used, thus the usage is limited to Porsche and Subaru today"
taken from this page:explanation of boxer engines

(sorry if my english is not perfect)

[Kudosdude]

Stenyak
I too have read the autozine article (it was a while ago mindyou), and while it was interesting from the point of view of having a balanced engine . . . it is highlighting a problem that does not really exist.

It's nice to see a bit of thought in this thread though, even if the thread is asking the impossible question.

By the way; there is no perfect engine configuration.

[stenyak]

kudosdude could you explain a bit more?
why do you say that it's a problem tha doesn't exist? i suppose if a engine is well balanced it will last more time, also the noise would be less, wouldn't it?

also you mention there's no perfect engine configuration. i think you mean that every car is a world and therefore a engine might be more suitable than other, while in another car it could be the other way. is that what you meant?

by the way, does it really matter the position of the cilinders when talking about power or torque (with the same cilinder size, of course)?
i dont know, but my opinion is that the power is then determined by other factors, such as aspiration method (normal superchargers, turbos...), the shape of the cylinders and pistons etc, number and position of valves, camshaft parameters (sohc-dohc, vvt...), type of injection, etc...

[crisis]

Originally posted by TheEnzo
yeah
stupid ferrari even used a FLAT-12
in teatrossa and boxer
they were no performence cars

Well theres another two. Anything lately?

[Kudosdude]

Stenyak

"I think you mean that every car is a world and therefore a engine might be more suitable than other, while in another car it could be the other way. is that what you meant?"

Spot on. A flat 12 ferrari engine is the WRONG choice for a fiat punto . . .

If engine balancing is such a big problem (as autozine would have you to believe) wouldn't you expect to see very few "unbalanced" engine configurations . . . why aren't we driving inline 3's instead of inline 4's?

Yes, a balanced engine is important . . . it's just not THAT important in the grand scheme of things.

Not the best answer I'm afraid, but I hope you get my gyst.

(P.S. yes the angle of the V/W does have an effect on power and torque curves, but I am led to believe that packaging is now the big engine design requirement)

[Scientist]

whoops...something went wrong with my computer...sorry

[henk4]

Well theres another two. Anything lately?

It appears like this thread is dead but I never saw it before.
Some remarks though: Also Subaru is producing a flat 6.
The flat 12 Ferrari used is the BB and the Testa Rossa was said not be a performance engine. Yet their design was derived from the flat 12 that was used in F1 since 1970, and was powerwise superior to the Cosworth V8, but became obsolete due to the development of undertray aerodynamics.
The power difference between the EVO and the WRX is zero as these engines are both designed for WRC use, where power is governed to 300 BHP.

[Matra et Alpine]

Stenyak
If engine balancing is such a big problem (as autozine would have you to believe) wouldn't you expect to see very few "unbalanced" engine configurations . . . why aren't we driving inline 3's instead of inline 4's?

Yes, a balanced engine is important . . . it's just not THAT important in the grand scheme of things.

careful we're not talking about the difference between blancing an operational engine, which is all about managing to get extra revs and performance by perfecting the manufactured componenets.

That's a million miles from building a new engine, ( especially confirguration ) and it running smoothly. In some configurations, without balancing contra-shafts the engine would throw itself apart within a few inutes.

You do see triples - check out Japanese micro cars and Triumph motorbikes. But they need a balncing shaft which the 4 doesn't. It's a trade-off between the weight saveed by losing a piston and the weight added to leep it balanced.

Of course in bikes, performance 4s will run counterbalance shafts. That's how they manage 250bhp and 18000 revs from 1300cc :-)

What 'balance' did you mean ?

[henk4]

in another thread (about a smoggy diesel) we have been discussing 5 cylinder engines, and I mentioned the VR5 and the inline 5 of the VAG group. The pioneer was the 300D from Benz. Thinking a little bit further there is f.i. now the D5 Volvo and also the 5 cylinder engine in the Fiat Stilo Abarth. They might need some balancing but these engines have absolutely no rough reputation.

[motorhead]

Inline 6 sux
V6 are good engines...
but the flat 6 rulez...
the sound of a boxer 6 of the Porsche, is music to my ears, and its reliability is great!!

inline 6 does not suck in fact take a look at the 330i engine - honestly(you can't argue with this)it is one of the best engines ever produced

[Alfahollic]

This tread is extremely poor. But interesting, i would have thought the layout wouldnt have that much of an effect in power output? more to do with body design/structure. Surely if the manufacturer wants to achive a certain amount of BHP out of the engine with the same displacement and number of cylinders in the layout of inline, V or horizontally apposed they would be able to do it.

[Matra et Alpine]

This tread is extremely poor. But interesting, i would have thought the layout wouldnt have that much of an effect in power output? more to do with body design/structure. Surely if the manufacturer wants to achive a certain amount of BHP out of the engine with the same displacement and number of cylinders in the layout of inline, V or horizontally apposed they would be able to do it.

Layout is important when trying to build a strong engine capable of high revs and power output.
And in-line 6 has a long "I" shape and the walls of the block must be thick and strengthened to cope with the stresses.
"V" shpe is easier to build in strength without LOTS of wasted metal.
by the time you get out to V12s some of the trade-offs are on the losing side again.
The angles of the V matter more for balance and power pulses.
I long for the day that F1 rules allow the teams to get out of V10s and play again. With modern materials a small stroke V12 or 16 could be an interesting engine

[henk4]

It is not without a reason that you don't see inline 8's anymore. You cannot extend the length of your engine indefinetely (also the crankshaft becomes of a critical length). Increasing the size of the cylinders also has its limits as you want to have a nice revving engine without having to worry too much about piston speed (witness the old Jaguar inline 6 with it's stroke of 106 mm)
That brings you automatically to the V shaped engines, and the angle of the V may differ although depending on the number of cylinders there appears to be a "natural" angle for each engine.

[Alfahollic]

Heres a very lazy engine. Redlineing at about 5500rpm. No wonder it won Bathurst 24hour 1 and 2.