R1100RS irritation

[JamesW]

This is a minor irritation that has bothered me since I discovered the issue about 7 years ago and I might have made mention of it on this forum, can't remember.  It seems that with the early R1100 bikes of which mine is having been built in 06/93 that BMW failed to include an oil temperature control to bypass the oil cooler until the oil is up to 5 bars on the oil temp gauge.  The issue is that the ECU (Motronic) won't switch from open to closed loop until 5 bars is reached.  What this means is the air fuel ratio will be 12.4:1 from startup until 5 bars at which time the ECU will switch from open to closed loop and lean the mixture to 14.7:1 which is too lean for this bike anyway hence many of us have installed an AFXIED or as in my case an Innovate Motor Sports wide band O2 sensor with LC-2 controller.  In the case of my bike if the outside air temp is around 50F it takes as much as 15 miles running time before the ECU commands closed loop which is ridiculous and if the air temp is in the low 40s it can take 30 miles to go closed loop.  BMW at some point saw the light and installed an oil cooler bypass system to eliminate this issue.  What I have done is fashion a plastic baffle (3.5"x7.5") which I can slip in front of the oil cooler on colder days then after engine warmup stop and remove the baffle.  I wish I could retrofit my bike with an oil cooler bypass system like the later oilheads have at a reasonable cost but I have no clue how to accomplish this.

 

This is a minor irritation but at times kind of pisses me off like yesterday when I went for a ride and forgot my baffle and it took 15 miles at speeds from 25 mph to 60 before it saw 5 bars and finally closed loop.  It is not good for the motor to run at 12.4:1 for excessively long periods of time and this is just an example of how BMW just doesn't seem to follow through on sound engineering.  The R1100 series should never have had this issue and there is just no excuse for slip ups like this but seems to be kind of typical in the case of some manufacturers.

 

I should say that I know what the open loop air fuel ratio is because the wideband O2 with LC-2 allows me to monitor my air fuel ratio in real time and I know exactly when the ECU does its thing and switches from open to closed loop.  I run my bike at 13.4:1 AFR in closed loop rather than the stock 14.7:1 which completely eliminates any sign of surging and produces a very smooth idle.  Fuel economy is good and averages around 49 mpg as long as I don't forget my baffle, grrrrrr.....

[JamesW]

If I could find a 12 volt 3-way solenoid valve it would be super easy to install with a switch on the dash for control.  When the oil temp display shows 5 bars just flip the switch and the solenoid operated valve would route the oil back through the cooler.  Probably would only need 1/2" fittings on the valve.

[dirtrider]

12 hours ago, JamesW said:

This is a minor irritation that has bothered me since I discovered the issue about 7 years ago and I might have made mention of it on this forum, can't remember.  It seems that with the early R1100 bikes of which mine is having been built in 06/93 that BMW failed to include an oil temperature control to bypass the oil cooler until the oil is up to 5 bars on the oil temp gauge.  The issue is that the ECU (Motronic) won't switch from open to closed loop until 5 bars is reached.  What this means is the air fuel ratio will be 12.4:1 from startup until 5 bars at which time the ECU will switch from open to closed loop and lean the mixture to 14.7:1 which is too lean for this bike anyway hence many of us have installed an AFXIED or as in my case an Innovate Motor Sports wide band O2 sensor with LC-2 controller.  In the case of my bike if the outside air temp is around 50F it takes as much as 15 miles running time before the ECU commands closed loop which is ridiculous and if the air temp is in the low 40s it can take 30 miles to go closed loop.  BMW at some point saw the light and installed an oil cooler bypass system to eliminate this issue.  What I have done is fashion a plastic baffle (3.5"x7.5") which I can slip in front of the oil cooler on colder days then after engine warmup stop and remove the baffle.  I wish I could retrofit my bike with an oil cooler bypass system like the later oilheads have at a reasonable cost but I have no clue how to accomplish this.

 

This is a minor irritation but at times kind of pisses me off like yesterday when I went for a ride and forgot my baffle and it took 15 miles at speeds from 25 mph to 60 before it saw 5 bars and finally closed loop.  It is not good for the motor to run at 12.4:1 for excessively long periods of time and this is just an example of how BMW just doesn't seem to follow through on sound engineering.  The R1100 series should never have had this issue and there is just no excuse for slip ups like this but seems to be kind of typical in the case of some manufacturers.

 

I should say that I know what the open loop air fuel ratio is because the wideband O2 with LC-2 allows me to monitor my air fuel ratio in real time and I know exactly when the ECU does its thing and switches from open to closed loop.  I run my bike at 13.4:1 AFR in closed loop rather than the stock 14.7:1 which completely eliminates any sign of surging and produces a very smooth idle.  Fuel economy is good and averages around 49 mpg as long as I don't forget my baffle, grrrrrr.....

Morning James 

 

Not all the early BMW 1100 bikes came without oil thermostat valves, the 1100RT had a remote mounted  oil thermostat from the get-go. That oil thermostat could probably be plumbed into your RS but I'm not sure where/how you could mount it as the real-estate is different in the mounting area  on your RS. (something to look into anyhow)

 

I haven't ever  tried this as I live in an area that when it gets cold even blocking off the oil cooler completely doesn't always get the  oil temp warm enough to remove the moisture out of the oil as the large alloy engine block & exposed oil sump area just radiates off so much oil heat that the oil  just never fully warms up.

 

I do believe that your early 1100 engine has about the same oil cooler  block fittings as the (remote) oil cooler block that the 1100RT does. It would probably just be a matter  of where to mount the darn thing & how to plumb the oil lines.

 

The early 1100RT remote oil cooler didn't work all the great anyhow so BMW went to an internal oil thermostat on the later 1100 & 1150  engines. 

 

When I used to ride 1100 bikes year round I had some plastic inserts that I made up to block off the oil cooler in very cold weather (still didn't get the oil temp high enough to remove oil moisture in real  cold temps)  but did help it to run slightly better/cleaner in the very cold. 

 

 

 

 

 

[TEWKS]

Kind of on this line of thinking.  

 

The old Autocar dumps use to have louvered grills which was pretty neat tech for the day.

 

 

[JamesW]

Morning DR,  yes that would be a problem trying to find enough realestate to mount that early RT rube goldburg looking thermostat.  I can't find a 3-way solenoid operated valve but I could use two 2-way valves but even that would require realestate that I don't have much of.  The baffle works pretty good where I live as long as I don't go too far inland in winter which I seldom if ever do anyway.  Don't really care much at all for the I5 corridor winter or summer for that matter.  More grrrrrr....

[dirtrider]

1 hour ago, JamesW said:

Morning DR,  yes that would be a problem trying to find enough realestate to mount that early RT rube goldburg looking thermostat.  I can't find a 3-way solenoid operated valve but I could use two 2-way valves but even that would require realestate that I don't have much of.  The baffle works pretty good where I live as long as I don't go too far inland in winter which I seldom if ever do anyway.  Don't really care much at all for the I5 corridor winter or summer for that matter.  More grrrrrr....

Afternoon David 

 

Did you try looking for a 12v  "open center" hydraulic valve, on most the open center is the default so that could be the (through the cooler)  channel. I use those on my tractor's remote hydraulics. You probably need to try to find one that is a 2 position rather than a continuous 12v to hold it open.

[JamesW]

Hi DR, No, in fact I have never heard of such a beast as an open center valve.  I've decided to just keep my baffle handy and put up with this idiosyncrasy.  Just not worth the effort and it could even lead to disaster as it would involve dealing with the high pressure oil lines as well as trying to cram all of these gizmos in a very small space.   These open center valves are also on the expensive side from the look of it.  Oh well, it was a thought.  

 

Thanks for your input as always.