K11 Owners Group

AUSBRICK · Posted: Wed Dec 23, 2009 7:07 pm Post subject: Cold air intake update

The cold air intake has now moved into stage 2 with an opened up exhaust and has made a huge difference it now pulls really hard right through the rev range. I used a k100 full exhaust system with the guts knocked out " very cheap solution". It's hard to believe its the same bike front wheel is off the deck quiet a bit and I have to be a little more careful with the throttle coming out of tight corners as I' ve had several cases ofrear wheel spin both of these didn't happen when standard so I know its not just that it sound like its faster with the noisier exhaust ( I did the same to the exhaust on my former k100 and it responded with better top end too) I always thought these motors would respond to a bit of work as bmw must have worked pretty hard to keep them below the 100 hp mark . The next stage will involve fuel consumption testing I always got 300 kms a tank no matter how I rode it hard, easy, even loaded up didn't make much difference.Also will be keeping an eye on the mixture via the plug colour its the most accurate way I know.I am almost getting this bike to what I want . A very comfortable tourer that can loose it touring gear to be a resonable sporty unit for the weekend squirts .More to come AusBrickMick
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92k1100 lt with sidecar. 93K1100 CAFE..86K75C.95 k1100lt

Rafal · Posted: Fri Dec 25, 2009 7:01 pm Post subject:

Hello!

Personally I am very interested with the solution you have made, but

Best regards,
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Rafal
K1100RS is a real beast (in Marrakesh Red)
K75S is a real beauty - she has gone Sad

, but not to far Smile

.

Flying Duck · Posted: Fri Dec 25, 2009 7:52 pm Post subject:

Have you given any thought to replacing the Motronic with something like a Megasquirt?

http://www.megamanual.com/index.html
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93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

Jim · Posted: Fri Dec 25, 2009 11:05 pm Post subject:

Rafal · Posted: Sat Dec 26, 2009 11:07 am Post subject:

AUSBRICK · Posted: Sun Dec 27, 2009 12:54 am Post subject: Reply on comments

G'day everyone , The pics previously posted pretty much show whats happening the only change has been black paint to make intake blend in a bit and the exhaust which just looks like a standard k 100 . Yes Duck I have thought about an after market injection controller but want to do a bit of testing as it is first . This hole project grew out of trying to make the 1100lt a bit more cooler to ride in the hotter summer weather, this has been very successful removing the airbox from under the tank , a three core rad and finnaly removed thermo altogether now allows more air flow and a clean exit which is keeping things much cooler all round motor has not even looked like getting hot even under hard riding in high temps and I no longer cook as the hot air that used to build up under the tank is no longer there .About to take off for some extended touring so I will post some pics and have some feed back on these mods after that . Cheers and happy trails. Ausbrick Mick
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92k1100 lt with sidecar. 93K1100 CAFE..86K75C.95 k1100lt

Flying Duck · Posted: Sun Dec 27, 2009 1:33 am Post subject:

Yeah, you gotta figure there's at least another 15-20hp there just sitting and waiting to be taken advantage of. That they detuned these things to keep them at 100hp is disgusting if you ask me.

Put in a tweakable FI computer and experiment with different fuel mapping on a dyno and I think you could get some decent performance out of the K1100 engine.

Then my common sense kicks in:

1) I have enough trouble keeping 100hp under check.I 'd buy a Busa in a heartbeat but I know I don't have the self-control - even though I'm 50 years old.

2) For the time and money you'd invest in tweaking a K11000, why not just buy a K1200RS? The pricing on them these days is incredibly reasonable. You get another 25hp or so with a telefork front end as well as the rubber engine mounting and you've got a great bike.

But I still like the klassic Ks for the fact they've got a real gas tank instead of Tupperware.and they're fast enough to give me wood without as much of a chance of putting me in jail.

Just how I see things.....
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93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

jarnbak · Posted: Sun Dec 27, 2009 11:58 am Post subject:

You dont have to buy a k1200rs. I have installed the cams from a eu k1200rs(same cams as k1/k100rs16) and there are a huge difference and then you still
have the short stroke of the k11.I installed the cams without any valve adjustment needed.
Regards Palle
(k11lt 92 with 208k km on the clock)

Flying Duck · Posted: Sun Dec 27, 2009 12:23 pm Post subject:

AUSBRICK · Posted: Sun Dec 27, 2009 4:59 pm Post subject:

Yeah I have come up with the same conclusions, but as stated this was a extra bonus from a experiment trying to get a cooler ride which has cost next to nothing and confirmed my thoughts on the detune that must have gone on to keep to the 100 hp. Cheers Mick . Ps I dont have any trouble hanging on to it, its called throttle control.
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92k1100 lt with sidecar. 93K1100 CAFE..86K75C.95 k1100lt

Flying Duck · Posted: Sun Dec 27, 2009 8:47 pm Post subject:

In looking at the parts catalog for a K100RS4V it looks like they made three sets of cams. One for a non-cat bike, one for a cat bike and another set special to Australia.
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93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

jarnbak · Posted: Sun Dec 27, 2009 10:02 pm Post subject:

There are a set on sale (284 grad non cat) on ebay http://cgi.ebay.de/Nockenwellen-BMW-K1-K1100LT-K100-K100RS-K1100RS-K1200RS_W0QQitemZ180447589073QQcmdZViewItemQQptZMotorrad_Kraftradteile?hash=item2a0383b2d1.
Regards Palle.

supercat1 · Posted: Mon Dec 28, 2009 7:04 pm Post subject:

and here comes my ignorance -- what do the cams do? is that what times the cylinder movements? how does the camshaft from a k12 improve the performance of the k11?
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(formerly) 1993 k1100rs

mtnroads · Posted: Mon Dec 28, 2009 9:57 pm Post subject:

I suggest you google "camshaft". The first hit is a great Wikipedia description that describes camshaft operation and includes a great graphic. Once you gain a little understanding, you will realize that the cam lobe "profile" is one of the primary factors in how well an internal-combustion engine breathes. Here's a very simplified explanation:

Cams with a taller lobe (lift) allow more of the air-fuel mixture to enter the cyclinder on the intake stroke and leave on the exhaust stroke. Cams with longer durations hold the valves open longer - opening sooner and closing later - allowing the mixture to flow better at higher rpm's. Duration is measured in degrees of crankshaft rotation, ie. 268 deg.

Of course there are trade-offs - higher lift cams can wear faster and allow valve float due to the steep ramps on the lobe and longer duration cams have more "overlap" - the period when both the intake and exhaust valves are open at the same time. This is necessary for strong high-rpm flow, but dilutes the mixture and bleeds off compression at low speeds - resulting in poor efficiency at low rpm and that lumpy-idle sound you used to hear a lot on muscle cars.

Back to the question - the K12 engines apparently used a cam profile that made more power - probably slightly higher lift, perhaps a bit more intake and/or exhaust duration. By swapping those cams into a K11 you can take advantage of the higher performance cam profile, allowing your engine to "breathe" better. Possibly at the expense of fuel economy or smooth idle characteristics.

Actually, the K1100 engines have a very conservative camshafts to begin with which is the reason they do not have a very peaky, or steep, power curve, and have a lot of usable torque. A hotter cam would allow better breathing at higher rpm's and you would see this reflected in the dyno charts. There's only so much that can be done to improve breathing with filters and exhausts - at some point if you want significant gains you either have to change the cams or go to forced induction, ie turbo.
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2012 R1200RT Midnight Blue
95 K1100LT Graphit (sold)
01 R1100RT Black (sold)