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Old 02-21-2013, 09:56 AM   #46
chasbmw
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Is this the same cam that is sold as part of the Seibenrock 1070 kit?

And are the horsepower figures taken from the crank?
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Old 02-21-2013, 12:14 PM   #47
Edelweiss-Motorsport
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Cam profile EM2V1

Hi Charles,

the EM2V1 is our asymmetrical street / sport profile.

The developement started approx. 15 years ago when some HPN owners where looking for a performance boost and less pinging in their 1043ccm / 97 mm bore engines.

I was racing BOT Beemers that time and was building my own engines and some engines for friends - this is how the scene found me.

We combined several well known conservative profiles and tested several overlap configurations until it works to perfection.

So under the line we first focused on dynamical processes and found a much better overall performance by using this simple part.

The pinging problem was solved more or less lets say to 95% by the cam.

As the valve lift in TDC was very very conservative on the std. 308 deg it was even so on the 320 deg cams that where common in this engines as HPN are using them. Since we are not in conflict with any emission rule we gained the overlap lift and influenced the dynamic compression a lot.

After this first step we looked on the squish and found that BMW was doing it wrong first and all the others are copying the angles / taper from each other and no one seems to put this very important point on the table to look on it.

So when HPN gets a customer complaining the common pinging problem they put an additional alu seal under the cylinder to reduce the compression....result was a lack of power and torque but the pinging was still there.

Frank Zapoa would say: we cured the disease but the symptom remains...

We did the exact opposite - a 180 deg turn in strategy, by shortening the cylinder and machining the piston to correspond with the cylinderhead.

Result was an even higher static compression ratio but since there is no gas at the squish band area there is nothing which can generate a pinging anymore.

Pinging was terminated power and torque was gained fuel consumption was going down drastically which the world traveling HPN customers liked too.

So we did countless numbers of this engines in the years and in a way all this started Edelweiss Motorsport.

Now our products are sold by all the whole sellers / cataloque / webshop companys in the field. They are our valued customers.

The big bore kit from siebenrock is developed by us and so we still deliver the cam.

When it comes to the EM big bore kit we go our own way with a more sophisticated version and we offer a 98 mm two or three ring version as well as a 100 mm version - they both can be combined with our long stroke cranks and therefor we have different conrod length available from 148 mm up to 152 mm.

Never change the compression ratio by the conrod length !!!

Back to the cam, now since the years went by we launched the third evo version of the EM2V1 with some even more modern profiles. The ramps are asymmetrical now too - so it was possible to lift up the performance and at the same time reduce the valve train noise.

The latest version of our cams are exclusively sold direct and are not available by any other party.

We have 30 different cam profiles available - most ex stock. So if you need something special let me know and I'm at your service with pleasure !

The figures are measured at the wheel corrected to the flywheel.

We use a state of the art dyno dynamics retarder system - numbers are very conservative.

Best reg.

Dirk

Edelweiss-Motorsport screwed with this post 02-21-2013 at 01:00 PM
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Old 02-21-2013, 12:22 PM   #48
supershaft
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[QUOTE=RGregor;20774850]Yes, dyno charts are a story of their own. I think you said that once or twice.
And you're right.
Looking at the charts shown in this article you see the hole in the torque curve at around 3000 rpm (version 3).
http://www.advrider.com/forums/showp...1&postcount=41

This seems to be characteristic for the SR-racing exhausts as I've seen it quite often.
On the dyno charts taken at SR racing you won't see it as they usually start at 3000 rpm or above.

Never believe the charts of the man who wants to sell you something. Or prove the result of his work.





Despite what rpm the chart starts at, I am real sceptical about low rpm dyno reading. I have been around them enough to know that the exact same engine and setup can look completely different depending on how you apply the brake and throttle and work a buttload of other variables. When it comes to first loading the engine, I would rather hear butt dyno reports than look at charts unless I was running the dyno and then I would still let how it felt while being ridden at those low rpms trump what the charts said if my butt dyno read different from the real dyno.

supershaft screwed with this post 02-21-2013 at 12:56 PM
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Old 02-21-2013, 12:32 PM   #49
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Quote:
Originally Posted by supershaft View Post
I would rather hear butt dyno reports than look at charts unless I was running the dyno.
I rode the bikes mentioned. Low end torque is impressive.
The rest isn't bad either ...
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Old 02-21-2013, 12:33 PM   #50
supershaft
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@ EM: Never increase compression with longer rods? Isn't that what you are doing with the standard pistons and 1.5mm longer rods in your favorite GS street setup?
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Old 02-21-2013, 12:53 PM   #51
supershaft
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Quote:
Originally Posted by RGregor View Post
I rode the bikes mentioned. Low end torque is impressive.
The rest isn't bad either ...
Compared to what? For this to work I hope you are going to say the other bike(s) with lower low rpm torque in the charts? Or did they all feel about the same despite the dyno charts?
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Old 02-21-2013, 01:30 PM   #52
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Conrod length

Dear Mr. Superschuft,

No - it is absolutely not what I'm doing with my 136,5 mm conrod !

How can I ? Singing the song of the perfect squishband all the time ?

Since I do not know if it was a rhetoric question or you really did not follow I will explain it to you:

The longer conrod will create a dramaturgical window for me to find material forming out a working squishband nothing more and nothing less.

The compression ratio has always to be a result of cylinderhead volume and / or piston dome.

So since the squish rules by far, first work out this parameter and later adjust the cr in the way you need it.

If you for example use a shorter conrod to reduce cr you will change the squishwork more then the cr which can never be the right way.

By the way If you run about 3 to 3,5 mm valve lift in TDC you should not use more then a cr of 9:1 !

Best reg.

Dirk

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Old 02-21-2013, 01:54 PM   #53
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Quote:
Originally Posted by supershaft View Post
Compared to what? For this to work I hope you are going to say the other bike(s) with lower low rpm torque in the charts? Or did they all feel about the same despite the dyno charts?
Seems to me that my posts were confusing.

In this thread some charts were posted or linked.
I never rode one of these bikes.

I referred to some friends' bikes, the ones that did the exhaust comparisons.
They had their bikes measured on a different (eddie current brake) dyno.
Just had a look at the charts, they start at 2000 rpm. Didn't remember right.

Reference for comparison was my own bike. It then had around 80Nm torque between 3000 and 7000 rpm with a flat curve (measured on same dyno).
The bikes I rode felt as if they had the same or more torque directly above idle. The charts told the same story.
The chart with the SR-racing headers did show a small dip at 3000rpm (not that deep as in the linked article), but you didn't feel it.
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Old 02-21-2013, 03:50 PM   #54
US_Marshall
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Dirk, with all the modifications that You perform, do you have a preference to a 2-1 exhaust or 2-2?
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Old 02-21-2013, 04:08 PM   #55
Edelweiss-Motorsport
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Exhaust preference

Yes I have - if it comes to performance and torque numbers as well as in what ranges the engines picking up i would always say go for a 2 in 1.

Since I do this I have fabricated and tested approx 50 different exhaust systems to get evidence about what I was reading and calculating.

A well done 2 in 1 will always perform out an even well done 2 in 2.

One of my best 1200 ccm long stroke engines is doing 128 HP using a 2 in 1.

The same engine must be using a very good 2 in 2 by racing regulations is pulling 122 HP

The same engine was winning the historic sidecar championship and by space reasons and regulations the customer was not willing to change to one of my systems - output was just 118 HP.

Since i use cnc ported heads and cnc machined seats all engines have a very similar base power and not a lot variation.

Best reg

Dirk
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Old 02-21-2013, 06:06 PM   #56
supershaft
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Quote:
Originally Posted by Edelweiss-Motorsport View Post
Dear Mr. Superschuft,

No - it is absolutely not what I'm doing with my 136,5 mm conrod !

How can I ? Singing the song of the perfect squishband all the time ?

Since I do not know if it was a rhetoric question or you really did not follow I will explain it to you:

The longer conrod will create a dramaturgical window for me to find material forming out a working squishband nothing more and nothing less.

The compression ratio has always to be a result of cylinderhead volume and / or piston dome.

So since the squish rules by far, first work out this parameter and later adjust the cr in the way you need it.

If you for example use a shorter conrod to reduce cr you will change the squishwork more then the cr which can never be the right way.

By the way If you run about 3 to 3,5 mm valve lift in TDC you should not use more then a cr of 9:1 !

Best reg.

Dirk
I guess I am still not following you. 1.5mm longer rod so you can remove material from the head? Why not start with higher CR pistons while spending less money? It would save machining on the cylinders too? Meanwhile you can take that much off the heads' gasket surface and match up the piston/head squish band. Personally, if I buy longer rods I am going to buy 15mm longer rods AND some pistons and rings and go that route. With a 94mm bore mind you. Personally and for the long haul, I think BMW was wise stopping at 94mm even though some of them thought that was too far.

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Old 02-22-2013, 02:50 AM   #57
chasbmw
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Dirk,

Many thanks for your very usefull contributions.

Charles
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Old 02-22-2013, 05:32 AM   #58
Edelweiss-Motorsport
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What route to go on our ride to Agadir ?

Hi again dear Superschuft,

Ok got your point but this is the general question - are you looking for more static compression ? What for ?

You want to spend money on pistons ? What for ?

The R 100 Pistons are of perfect Material - they run forever, they never fail, they can take the power with ease and they are to find in all that engines most of all times in very good condition.

So the longer rod is my favorite combo since you just machine the piston, cylinder and head remains unmachined most times.

We never take away any material from the head if possible - hold in mind that 75% % of the heat is absorbed by the head, so you want as much material there as possible. This is the reason why we came up with our aluminium head gaskets
which then transport the heat into the cylinders much better.

Ok - compression ratio is an essential point but the value must be correct in accordance to the application and most important to the cam.

For all you do on the street up to 85 to 90 HP you do not need more than 9:1.

My 100 HP street engines run with a cr of 9,5:1.

Gaining the compression you must do dynamically by gas flow and the best understanding about the max possible loading and filling.

High static compression ratios on our engines are outdated - they are coming from times where cams where used that start performing from 5000 rpm upwards if comressed statically below 11,5:1.

To overcome this effect the static compression ratios must be lifted.

That was the time Michel and others where using 45 - 50 mm exhaust tubes and ports that where as big as they where looking for 200+ HP.

A missunderstanding about cr is leading you into a rough running engine with overheated combustion chambers and piston domes.

So under the line it can not be more effortless and pricy than using the material which is already there.

Machine your cylinder at the bottom, machine the piston at the squishband zone, buy a set of Aluminium head gaskets, a cam and a header and off you go launching the rocket.

If you want a set of nice light and strong I Shaft conrods ok - if not also OK !

One more time - you do not need a better static compression ratio then that comes up by doing the squish, take it for granted and enjoy life.

I have quite a good and close contact to BMW so knowing what was tested and what where the reasons not going with bigger bores was making me optimistic going up to 100 mm since more then a decade now without any fail.

I was casting my own cylinders preparing them to be strong enough for a bore of 105 mm and having more finning surface to cope better with the upcomimg thermal impact.

So do not worry about the 98 mm - even the bored std. cylinders sold from Siebenrock can take it.

When I was starting the 98 mm project i also used bored an replated ones in several race and street applications. The result and information i generated by doing this was leading me to the 100 mm bore.

Just because i always look for the best possible available on this planet i did the investment of tooling and casting the cylinders on my own behalf.

So relax about the bore - if the budged is available go for it !

There is nothing but an airhead lifting the front wheel at third gear without using the clutch.

There is nothing but the Ducati or oil head drivers face after he is looking behind at 200km/h expecting you to be far away - in fact you start to overtake him because it gets so boring in his slipstream.

And yes it is don quijote against the windmill - but it is priceless fun to have.

This is what it is all about - just let us all together have some good fun with this wonderful BMW engines, and then best possible share it...

Dirk

P.s. Charles - it is my pleasure !

Edelweiss-Motorsport screwed with this post 02-22-2013 at 05:38 AM
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Old 02-22-2013, 09:58 AM   #59
RGregor
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Servus Dirk!

Also, jetzt musst Du nur noch was gegen die 336er Nocke schreiben, dann hast Du im Zeitraffer alle Punkte infrage gestellt, für die sich Herr SS hier stark macht. Ohne die Alternativen überhaupt zu kennen.

Und sonst, alles im Lot?

Gruß aus München

Rudi
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Old 02-22-2013, 10:17 AM   #60
chasbmw
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It would be useful to get Dirk's views comparing the sorts of cams that are available today against the BMW 336 cam. We have so much choice nowadays compared to only a few years ago.
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