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Offline Grootseun

BMW Boxer engine..
« on: April 03, 2007, 09:01:12 am »
See origina article here (so we dont get sued for copyright infringement)

BMW Boxer - out for the count?
03/04/2007

BMW's Boxer engine is the foundation on which legends like the R80 and more recently R1150GS Adventure was built.

Will it stand the test of time to become compliant to emission regulations?

Right now Bayerische Motoren Werk is in its biggest struggle - both internally and externally.

The Boxer engine is perhaps an even more characteristic trademark than Harley's V45.

After a long and exclusive conversation with Markus Biebricher at the BMW-Motorrad factory we know that BMW have several options to replace the air-cooled Boxer engine.

But inside the 100 000 motorcycles-sold-a-year firm, the opinion is divided.

To make the current 1200cc Boxer engine compliant with future emission and noise regulations it will have to be dropped from the line-up for a completely new design.

If BMW is to continue with its traditional Boxer design there are several problems.

The major problem is that a liquid cooled DOHC version of the Boxer engine would simply be too wide. You wouldn't be able to corner such a motorcycle without ploughing up the tar with the cylinder heads.

"It would be too wide and would not corner properly," Markus said.

BMW also stated in our phone interview that without the Boxer engine BMW is afraid it will loose some of its uniqueness and be left with engines that are more similar to other manufacturers.

As we all know BMW have their in-line four, parallel twin and single cylinder engines in addition to the Boxer. So one of the alternatives to replace the Boxer line-up would be to use parallel twin engines rather than the Boxer.

But then again, that would dramatically change the look of the large BMW GS's. Can you imagine a BMW R1200 GS without the two cylinder heads sticking out on each side? Neither can we and this is a big dilemma for the BMW engineers at the moment.

The Boxer engine is the jewel in the crown and centre of attention for BMW. Biebricher said that 1 or 2 years is not enough for BMW to find a solution and that there are not even drawings of such a replacement for the R-series.

At the same time, BMW is a company in growth and a huge changing process is taking place right now. They are sharpening their image with more and more sporty models.

But the company is still finding its way in a market bound to change dramatically. Harley-Davidson, Buell, Moto Guzzi and Ducati are in the same situation. Who will find the best solutions?

Whaddya think esteemed members?
 

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BMW Boxer engine..
« Reply #1 on: April 03, 2007, 09:34:13 am »
Let them do the "completely new design" on the boxer engine. Sommer make it lighter at the same time.  :D
 

Offline >Herman<

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« Reply #2 on: April 03, 2007, 09:53:09 am »
Late April fool joke  :?  :shock:

Offline tsiklonaut

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« Reply #3 on: April 03, 2007, 10:00:49 am »
European emissions regulations are hyper over hyped IMHO. They count every gram of CO.

I ferking don't know why they step into motorcycles field while there are ZILLION loads of more cars driving around that have considerably higher emissions. Bigger capacaty motorcycles make very, very small minority of combustion engined moving vehicles in Europe.

I think EU council (read: paperwork corrupt and confused people who don't have anything to do in the office) want to place a huge political pressure on the motorcycles, to find widely popular political reasons to wipe motorcycles out of the traffic. They come up with reasons like they are dangerous, high emissions, hazardous lifestyles etc etc reasons every year.

R1100/1150/1200 boxers with catalythic converters were/are among the best in the lowest emissions air/oil cooled engines, I honestly don't know what's all that bollocks is about they talk there in this article. LOADS of motorcycle people have free-flowing-high-decibelled-non-catalythic-converted-high-CO-levelled Akrapovices/Yoshimuras/Remuses etc on their bikes who create much more emissions and noise than those with stock settings, rather bash them if they don't have anything to do in the office, rather than bashing those who try to be more enviromentally friendly like the BMW is and who is an important "roll-model" for other makes (BMW was the first make who started to use catalythic converters on motorcycles btw), in my humble opinion anyways.

All in all I think it's another wind up by EU's narrowminded politicians. It's a shame to live in the EU which is heaven for bureaucracy.
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Offline tok-tokkie

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« Reply #4 on: April 03, 2007, 10:36:11 am »
Why would the cylinder head need to be significantly bigger?  I presume it will have to be water cooled but that hardly makes it much bigger.

Two years to do an engine re-design; MotoGP engines have just been re-done in slightly less time than that.
 

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« Reply #5 on: April 03, 2007, 01:26:50 pm »
If you believe that a water cooled engine emits less pollutants than a parallel air-cooled twin, you'll believe anything. :roll:

What a load of crap. :twisted:
 

Offline Welsh

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« Reply #6 on: April 03, 2007, 02:15:05 pm »
Quote from: "tok-tokkie"
Why would the cylinder head need to be significantly bigger?  I presume it will have to be water cooled but that hardly makes it much bigger.

Two years to do an engine re-design; MotoGP engines have just been re-done in slightly less time than that.


Sounds like B*****KS to me as the name for this series is Oil Heads, notice the Oil Cooler, the heads area already OIL NOT AIR COOLED, someone picked on an April 1 joke.

But, the regulations are tricky, irrelevant to this, but I just read a report on "CAR" exhaust manifolds being cast in stainless steel by the investment casting process. Stainless does not conducts heat as well so your burn off in the first 20 seconds of starting before the cat warms up is better, this may be why BMW put cat in the headers? So this story is not closed.

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Offline lecap

Re: BMW Boxer engine..
« Reply #7 on: April 04, 2007, 07:59:50 am »
I don't think the article is a fools day joke nor b*****ks.
Quote from: "Grootseun"


The major problem is that a liquid cooled DOHC version of the Boxer engine would simply be too wide. You wouldn't be able to corner such a motorcycle without ploughing up the tar with the cylinder heads.



The technical reasons for a liquid cooled DOHC concept are not related to exhaust emissions but to noise emissions:

The Oilhead in particular and air / oil cooled engines in general are noisy bastards and we are talking mechanical noise here not the safety features leaving the busy end of your nice racing pipe  :)
As a rule of thumb you can say that the more moving parts a valve drive has the more noisy it gets. The Oilhead with its combination of chain driven side cams, buckets, pushrods and rocker arms is predisposed to make noise like a bag of pebbles in a tumble drier.
Looking at mechanical noise the combination of DOHC (preferably belt driven) and buckets is near ideal. Modern cam chains are not bad either.

It's correct that there is no good reason for a water cooled engine to have lower exhaust emissions than an oil cooled or air cooled engine. But the water around the sleeve definitely reduces mechanical noise originating from the piston.

Maybe BMW will come with a solution like building a very flat V2 which will make traditionalists happy still looking more or less like a flat twin but allowing more space and height for the cylinder heads without having to raise the engine in the chassis.

I would love to see a water cooled 150�° V twin. DOHC con cam radial four valve head.
Recent  developments show that BMW is open to new ideas.
And I am sure the next R will be the best ever.
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Offline LuckyStriker

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BMW Boxer engine..
« Reply #8 on: April 04, 2007, 09:06:24 am »
Quote from: "popipants"
BMW Boxer - out for the count?
03/04/2007 08:14
BMW's Boxer engine is the foundation on which legends like the R80 and more recently R1150GS Adventure was built.
Will it stand the test of time to become compliant to emission regulations?
Right now Bayerische Motoren Werk is in its biggest struggle - both internally and externally.
The Boxer engine is perhaps an even more characteristic trademark than Harley's V45.
After a long and exclusive conversation with Markus Biebricher at the BMW-Motorrad factory we know that BMW have several options to replace the air-cooled Boxer engine.
But inside the 100 000 motorcycles-sold-a-year firm, the opinion is divided.
To make the current 1200cc Boxer engine compliant with future emission and noise regulations it will have to be dropped from the line-up for a completely new design.
If BMW is to continue with its traditional Boxer design there are several problems.
The major problem is that a liquid cooled DOHC version of the Boxer engine would simply be too wide. You wouldn't be able to corner such a motorcycle without ploughing up the tar with the cylinder heads.
"It would be too wide and would not corner properly," Markus said.
BMW also stated in our phone interview that without the Boxer engine BMW is afraid it will loose some of its uniqueness and be left with engines that are more similar to other manufacturers.
As we all know BMW have their in-line four, parallel twin and single cylinder engines in addition to the Boxer. So one of the alternatives to replace the Boxer line-up would be to use parallel twin engines rather than the Boxer.
But then again, that would dramatically change the look of the large BMW GS's. Can you imagine a BMW R1200 GS without the two cylinder heads sticking out on each side? Neither can we and this is a big dilemma for the BMW engineers at the moment.
The Boxer engine is the jewel in the crown and centre of attention for BMW. Biebricher said that 1 or 2 years is not enough for BMW to find a solution and that there are not even drawings of such a replacement for the R-series.
At the same time, BMW is a company in growth and a huge changing process is taking place right now. They are sharpening their image with more and more sporty models.
But the company is still finding its way in a market bound to change dramatically. Harley-Davidson, Buell, Moto Guzzi and Ducati are in the same situation. Who will find the best solutions?


Sorry popipants but I deleted your thread for reasons of duplication
 

Offline Stofstreep

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« Reply #9 on: April 04, 2007, 09:56:33 am »
Damn LeCap :shock:

You know your stuff :!:  Sound Plausable

What if they shorten the stroke and increce the bore? :D
What would the limit be for stroke?
Proberbly limited by the cam thickness :?:
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Offline tok-tokkie

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« Reply #10 on: April 04, 2007, 10:39:24 am »
My previous bike was a Honda VFR.  In 2003 they changed to the vtec engine.  This has no power, torque or fuel economy advantages over the previous engine.  There was a lot of discussion on the US vfr board about why Honda had added so much complexity for no apparent gain.  Someone found an official Honda article showing that it was to reduce mechanical noise.  The pre-vtec engine had gear drive to the 2 banks of cylinders on the right side of the engine & these gave a beautiful mechanical whine, the previous vesion had the gear drive in the middle of the engine with less gear whine.  The vtec had chain drive and was mechanically much quiter. Honda had to introduce other quitening things like a flapper valve on the airbox to meet noise regulations.  It seems plausable to me that BMW is faced with similar problems with the next generation of European noise regs
 

Offline tsiklonaut

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« Reply #11 on: April 04, 2007, 11:11:44 am »
Quote from: "Stofstreep"

What if they shorten the stroke and increce the bore? :D
What would the limit be for stroke?
Proberbly limited by the cam thickness :?:


Shortening stroke and thus making it high-rev screamer will push away 90% of potential boxer buyers.

Why I chose my 1100 was because of the low grunt torque. I've tried many and I haven't felt any bike with similar cc that pulls so well on low rpms, no I4, V4, parallel or v-twin maches the feel I get on my GS with my back side on this. Many toss it in the high rpms, but these I use very little so it's not practical for my needs.

From BMW as innovative make would be nice to see pneumatic valve train on the new boxers. They even can make longer stroke (=better torque) and at the same time reduce the cylinder's width. Along with mechanically considerably efficent, almost completely silent, considerably lighter, the penumatronic concept will also allow variable valve operation, meaning they can optimize the engine purpose even better - wheter it'll be torque oriented - massive grunt straight out of idle rpms (this is what I prefer myself, pulls like a diesel!) or to generate lot of horsepower in the higher revs. It can have both of this with variable valves. Pneumatronic will give more cornering space, overall the engine placed very low CoG. This would make an ideal boxer, imho.

Many makes have been experimenting with pneumatronic concept, especially in F1, but none have come up with it comercially, tho...

I always fancied about possibility of the boxer that has simultaneous ignition timing - both cylinders fire at the same time, meaning the crankshaft will be "big-bang pushed" ideally @ 180 degrees, the most effective torque "wrenching" position. It's like a single cylinder, but cylinders are on the both sides and working at the same time! Would be interesting to know if that kind of concept will be beneficial for flatter torque curve characteristics or not. But I'm guessing it's not, it'll be too low revving, like a sewing machine, too much vibrations and powerless on high revs, otherwise BMW would use it already.

Or a turbo diesel boxer (the cylinders width will stay about the same, turbo they can fit above the engine with a bit remodeling, feeding systems behind the cylinders), 200Nm@2000rpms, over 100 miles per gallon fuel efficency, sounds good, innit?  :D
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Offline michnus

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« Reply #12 on: April 04, 2007, 11:15:32 am »
Quote
I always fancied about possibility of the boxer that has parallel ignition timing - both cylinders fire at the same time, meaning the crankshaft will be "big-bang pushed" ideally @ 180 degrees, the most effective torque "wrenching" position. It's like a single cylinder, but cylinders are on the both sides and working at the same time! Would be interesting to know if that kind of concept will be beneficial for flatter torque curve characteristics or not. But I'm guessing it's not, it'll be too low revving, like a sewing machine, too much vibrations and powerless on high revs, otherwise BMW would use it already.


That's what they have done on the 800 now.

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« Reply #13 on: April 04, 2007, 11:19:14 am »
Hell but you lot sure are technically advanced okes. I feel like an idiot . :D

Interesting topic 8)
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Offline Welsh

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« Reply #14 on: April 04, 2007, 01:02:52 pm »
Quote from: "michnus"
Quote
I always fancied about possibility of the boxer that has parallel ignition timing - both cylinders fire at the same time, meaning the crankshaft will be "big-bang pushed" ideally @ 180 degrees, the most effective torque "wrenching" position. It's like a single cylinder, but cylinders are on the both sides and working at the same time! Would be interesting to know if that kind of concept will be beneficial for flatter torque curve characteristics or not. But I'm guessing it's not, it'll be too low revving, like a sewing machine, too much vibrations and powerless on high revs, otherwise BMW would use it already.


That's what they have done on the 800 now.


You sure? They go to TDC at the same time, but I assume one is exhausting while the other is on the firing stroke, its not a two stroke remember.

LeCap I agree with, in most ways in that noise is part of the issue. But I have seen big Kawa motors etc with liquid cooling which are no bigger than an air cooled motor so whats the issue on width?

Emissions is still part of it on an aircooled motor, the motors warm up slower in cold conditions than a liquid cooled motor, resulting in higher emissions on starting and when cool. It is this thermal control that may be required in order to meet legislation, hence the liquid cooling requirement.

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Offline Grootseun

BMW Boxer engine..
« Reply #15 on: April 04, 2007, 01:07:36 pm »
Quote from: "African Welsh"
Quote from: "michnus"
Quote
I always fancied about possibility of the boxer that has parallel ignition timing - both cylinders fire at the same time, meaning the crankshaft will be "big-bang pushed" ideally @ 180 degrees, the most effective torque "wrenching" position. It's like a single cylinder, but cylinders are on the both sides and working at the same time! Would be interesting to know if that kind of concept will be beneficial for flatter torque curve characteristics or not. But I'm guessing it's not, it'll be too low revving, like a sewing machine, too much vibrations and powerless on high revs, otherwise BMW would use it already.


That's what they have done on the 800 now.


You sure? They go to TDC at the same time, but I assume one is exhausting while the other is on the firing stroke, its not a two stroke remember.

LeCap I agree with, in most ways in that noise is part of the issue. But I have seen big Kawa motors etc with liquid cooling which are no bigger than an air cooled motor so whats the issue on width?

Emissions is still part of it on an aircooled motor, the motors warm up slower in cold conditions than a liquid cooled motor, resulting in higher emissions on starting and when cool. It is this thermal control that may be required in order to meet legislation, hence the liquid cooling requirement.

Welsh  8)


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Offline Welsh

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« Reply #16 on: April 04, 2007, 01:49:03 pm »
Quote from: "Grootseun"
Quote from: "African Welsh"
Quote from: "michnus"
Quote
I always fancied about possibility of the boxer that has parallel ignition timing - both cylinders fire at the same time, meaning the crankshaft will be "big-bang pushed" ideally @ 180 degrees, the most effective torque "wrenching" position. It's like a single cylinder, but cylinders are on the both sides and working at the same time! Would be interesting to know if that kind of concept will be beneficial for flatter torque curve characteristics or not. But I'm guessing it's not, it'll be too low revving, like a sewing machine, too much vibrations and powerless on high revs, otherwise BMW would use it already.


That's what they have done on the 800 now.


You sure? They go to TDC at the same time, but I assume one is exhausting while the other is on the firing stroke, its not a two stroke remember.

LeCap I agree with, in most ways in that noise is part of the issue. But I have seen big Kawa motors etc with liquid cooling which are no bigger than an air cooled motor so whats the issue on width?

Emissions is still part of it on an aircooled motor, the motors warm up slower in cold conditions than a liquid cooled motor, resulting in higher emissions on starting and when cool. It is this thermal control that may be required in order to meet legislation, hence the liquid cooling requirement.

Welsh  8)


sutch along winded way to say you need a beer Welsh.. :D  :D


Sheesh we are sharp today arent we.

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Offline lecap

BMW Boxer engine..
« Reply #17 on: April 05, 2007, 08:56:17 am »
Re: mechanical noise:
During the development of the Oilhead there was controversy at BMW Technische Zentrale between "Traditionalists" which finally got the Oilhead as it is today and "Modernists" who rightfully claimed that the mechanical noise of the Oilhead will make it an obsolete construction much sooner than a more radical alternative concept.

The issue on engine width and cornering ground clearance is primarily about a DOHC construction, not that much about the water cooling.
More than the camshafts themselves the sprockets and chains or pulleys driving them need a lot of space. (Remember that a cam sprocket needs to be twice the diameter of the counterpart on the main shaft).
Bevel gear driven cams (although historically known from BMW's racing flat twins and also having been discussed in the early development stages of the Oilhead) are prohibtive in cost, weight and complexity and share to be prohibitive in the flat twin setup with a straight gear construction for being noisy.

Making the engine "lower" by increasing bore and decreasing stroke does not work without limitation. As mentioned you need a bit of stroke to get reasonable torque. The other limit is the shape of the combustion chamber.
A very large and very flat combustion chamber will need multiple ignition plugs to fire and burn the load properly. Today's undersquare (=less stroke than bore)automotive and motorcycle engines are close to the limits.

I think the pneumatronic concept of valve control is not ready for introduction into mass production yet.
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Offline Welsh

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« Reply #18 on: April 05, 2007, 09:23:41 am »
Quote from: "lecap"
Re: mechanical noise:
During the development of the Oilhead there was controversy at BMW Technische Zentrale between "Traditionalists" which finally got the Oilhead as it is today and "Modernists" who rightfully claimed that the mechanical noise of the Oilhead will make it an obsolete construction much sooner than a more radical alternative concept.

The issue on engine width and cornering ground clearance is primarily about a DOHC construction, not that much about the water cooling.
More than the camshafts themselves the sprockets and chains or pulleys driving them need a lot of space. (Remember that a cam sprocket needs to be twice the diameter of the counterpart on the main shaft).
Bevel gear driven cams (although historically known from BMW's racing flat twins and also having been discussed in the early development stages of the Oilhead) are prohibtive in cost, weight and complexity and share to be prohibitive in the flat twin setup with a straight gear construction for being noisy.

Making the engine "lower" by increasing bore and decreasing stroke does not work without limitation. As mentioned you need a bit of stroke to get reasonable torque. The other limit is the shape of the combustion chamber.
A very large and very flat combustion chamber will need multiple ignition plugs to fire and burn the load properly. Today's undersquare (=less stroke than bore)automotive and motorcycle engines are close to the limits.

I think the pneumatronic concept of valve control is not ready for introduction into mass production yet.


Many moons before the oil heads, I saw a design built by a German industrialist. his own OHC 4 valve heads with bevel drives and the cylinders canted up by about 5 degrees, for more ground clearance.

Although DOHC is nice, it is not essential and for noise the belt drives are probably best, but agreed a bit bulky.

So it is still possible I think, just gets more difficult. Also, the weight saving measures seen on the 1200 for instance have the effect of allowing more apparent mechanical noise to "escape".

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« Reply #19 on: April 05, 2007, 10:46:52 am »
Quote from: "African Welsh"
Quote from: "lecap"
Re: mechanical noise:
During the development of the Oilhead there was controversy at BMW Technische Zentrale between "Traditionalists" which finally got the Oilhead as it is today and "Modernists" who rightfully claimed that the mechanical noise of the Oilhead will make it an obsolete construction much sooner than a more radical alternative concept.

The issue on engine width and cornering ground clearance is primarily about a DOHC construction, not that much about the water cooling.
More than the camshafts themselves the sprockets and chains or pulleys driving them need a lot of space. (Remember that a cam sprocket needs to be twice the diameter of the counterpart on the main shaft).
Bevel gear driven cams (although historically known from BMW's racing flat twins and also having been discussed in the early development stages of the Oilhead) are prohibtive in cost, weight and complexity and share to be prohibitive in the flat twin setup with a straight gear construction for being noisy.

Making the engine "lower" by increasing bore and decreasing stroke does not work without limitation. As mentioned you need a bit of stroke to get reasonable torque. The other limit is the shape of the combustion chamber.
A very large and very flat combustion chamber will need multiple ignition plugs to fire and burn the load properly. Today's undersquare (=less stroke than bore)automotive and motorcycle engines are close to the limits.

I think the pneumatronic concept of valve control is not ready for introduction into mass production yet.


Many moons before the oil heads, I saw a design built by a German industrialist. his own OHC 4 valve heads with bevel drives and the cylinders canted up by about 5 degrees, for more ground clearance.

Although DOHC is nice, it is not essential and for noise the belt drives are probably best, but agreed a bit bulky.

So it is still possible I think, just gets more difficult. Also, the weight saving measures seen on the 1200 for instance have the effect of allowing more apparent mechanical noise to "escape".

Welsh  8)


master welsh ... please explain your last sentence to me in english that i can understand , i see no correlation between weight and mechanical noise escaping... if weight = 50 kg an noise equal 50 db does that mean if weight = 25kg noise = less?
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