Piston Banks

[Matt]

I also chose the Boxeer engine for the reasons Martinbro said above. Thanks for the technical insight! I learned some new things.

[BMW_Dude]

I voted inline!

If it creates such engines such as the great one in the M3, what's not to like?

[Brookside]

the boxer engine configuration is superior engineering
(thanks for the info Martinbo) but.....
Inline.....BMW's inline 6's are works of art-
A little engine vibration works for me!!!

[martinbo]

Originally Posted by James

the boxer engine configuration is superior engineering
(thanks for the info Martinbo) but.....
Inline.....BMW's inline 6's are works of art-
A little engine vibration works for me!!!

It would be remiss of me to say that one layout is superior to another, I really just wanted to get across that a Boxer layout is my favourite because I identify with certain benefits that Boxer engines provide.

I'm almost dead certain that an in-line six is smoother (less vibration) even than a Boxer engine. They are fantastic in that respect. Did I mention that I'm an absolute fan of the M/S54 in the Z4 and M3 and the new N52 in the E90? Untouchable in their class for character and linear power delivery imo...

[warot]

Originally Posted by martinbo

It would be remiss of me to say that one layout is superior to another, I really just wanted to get across that a Boxer layout is my favourite because I identify with certain benefits that Boxer engines provide.

I'm almost dead certain that an in-line six is smoother (less vibration) even than a Boxer engine. They are fantastic in that respect. Did I mention that I'm an absolute fan of the M/S54 in the Z4 and M3 and the new N52 in the E90? Untouchable in their class for character and linear power delivery imo...

Not to mention are better for 50/50 weight ratio too. The 3.0 liter in the E90 is absolutely magnificent. That sound will play in my head over and over again.

That's my choice for "everday" car... But a V configuration is a must for performance purposes.

P.S. ROtary engines are such gas guzzlers

[martinbo]

Originally Posted by warot

Not to mention are better for 50/50 weight ratio too. The 3.0 liter in the E90 is absolutely magnificent. That sound will play in my head over and over again.

That's my choice for "everday" car... But a V configuration is a must for performance purposes.

P.S. ROtary engines are such gas guzzlers

Yes kinda, but when it comes to that 50:50 weight distribution inline engines aren't as ideal as a V layout as the engine is, obviously, longer. This necessitates a push far back into the engine bay, 3 series style. So warot, in this case it's the engine placement rather than its layout that achieves this distribution. What the inline 6 does do is concentrate the engine mass along the centre line of the car which probably goes someway to improving roll characteristics.

V engines are only good where displacement is the primary consideration. Which is just about in every performance car these days. So yes, in that respect I'm inclined to agree with you.

Rotaries. Nah. I'm follower of the piston faith.

P.S. your avatar picture, where was that taken? Main skidpan at Gerotek?

[warot]

Originally Posted by martinbo

Yes kinda, but when it comes to that 50:50 weight distribution inline engines aren't as ideal as a V layout as the engine is, obviously, longer. This necessitates a push far back into the engine bay, 3 series style. So warot, in this case it's the engine placement rather than its layout that achieves this distribution. What the inline 6 does do is concentrate the engine mass along the centre line of the car which probably goes someway to improving roll characteristics.

V engines are only good where displacement is the primary consideration. Which is just about in every performance car these days. So yes, in that respect I'm inclined to agree with you.

Rotaries. Nah. I'm follower of the piston faith.

P.S. your avatar picture, where was that taken? Main skidpan at Gerotek?

Ah yes very good point, you are full of knowledge. I always figured that BMW's inline is better for 50/50 weight balance rather than cornering abilities, but your argument makes perfect sense.

Sorry that I'm not so good with engine knowledge (I'm trying to learn as much as I can), but what is stopping from someone making an inline 12? Just curious.

P.S. Wow Martinbo, good eyes, I didn't think anyone in the world would ever notice that. I know that you've been at Gerotek numerous times but that's insane. So yes, our department (Analysis and Test Center... BMW) took 17 E90's to Gerotek and spent all day there. My avatar is a picture of a 320d going around the .. crap forgot the name... that big circle with the patch of water at the end to test aquaplanning... at 70 kmh.

[martinbo]

Originally Posted by warot

Sorry that I'm not so good with engine knowledge (I'm trying to learn as much as I can), but what is stopping from someone making an inline 12? Just curious.

You don't have to apologise. We've all got lots to learn and the only way is to ask questions. What this forum needs is an engineer who can explain technical concepts in layman's terms in much the same way as Jeff Daniels of EVO or Jake Venter of Car magazine does. I run out of answers pretty quickly when things get really technical.

To the best of my knowledge an in-line twelve is unfeasible for a number of reasons:
1. It's a nightmare to package such a long thin engine in any practicable application.
2. In-line engines are economically more expensive to engineer than a V engine of the same number of cylinders. An in-line engine block and crankshaft use more raw material in the manufacturing process. An in-line 6's crank is decidely longer and more expensive to engineer than an equivalent V crank.
3. From a torsional rigidity point of view a shorter crank is less prone to flex than a longer one. So in an in-line twelve, crank stiffness (or rather the lack thereof) would be a big problem. Needless to say a flexing or twisting crankshaft is a very bad thing.

Originally Posted by warot

P.S. Wow Martinbo, good eyes, I didn't think anyone in the world would ever notice that. I know that you've been at Gerotek numerous times but that's insane. So yes, our department (Analysis and Test Center... BMW) took 17 E90's to Gerotek and spent all day there. My avatar is a picture of a 320d going around the .. crap forgot the name... that big circle with the patch of water at the end to test aquaplanning... at 70 kmh.

Yup, I'm at Gerotek every six weeks all weekend in my capacity as instructor for Subaru, so I'm familiar with the facility. You're talking about the Dynamic Circle which is exactly as you say - to test aquaplaning.
Did you get to drive on the dynamic handling track? That's flippin awesome.

I remember being asked to instruct for the E90 and E65 facelift by Gerotek, unfortunately my SAP project commitments precluded me from attending. I would've loved to have been there given my enthusiasm for BMWs.

[Snake Vargas]

I suppose each type of engine layout has its own benefits, so I'm not such a fan over any other. Inline engines can be smooth (well, inline 4 engines sometimes aren't), boxer engines have all the benefits as Martin said , the V layout is good for space efficiency and reasonably simple construction, the W layout is more space efficient WRT (with respect to) number of cylinders and therefore swept capacity, but it does restrict the angle of the banks and also makes the block somewhat complex to engineer, and rotary engines are small and do have a low centre of gravity like the boxer engines.

I suppose I'm a fan of the boxer for the reason of engineering elegance - use the engine's own reciprocating mass to cancel out vibrations, and on the same plane so that it is most effective. That's just smart. Low centre of gravity etc. are just icing on the cake.

That said, I can understand why not many cars use the engine. It does make packaging difficult. So, my "everyman's choice" would be the V-layout. Compact and simple, efficient space WRT capacity.

[Matt]

Don't boxer engines tend to be heavier than regular engines? Oh yeah and people seem to forget that Rotary engines work off gaining momentum, which means they have a huge amount of horsepower per litre. Boxers also take up alot of horizontal room. Am I off. If so please correct...

I SAW MY FIRST M5 today......... They just got to America so it was a big deal for me.