Dear Editor and Fellow Club Members:
What? Here's April already with a new riding season upon us as snow melts, flowers appear, and the road opens wide. The first official year of the new 1100 twin was a unbelievable success. BMW's "triple-S" formula of Safety, Styling, and Speed proved correct and led to record sales plus many pages of very good press. BMW USA sales for 94 were up 22.3 percent over 1993 with the new "oilhead" twin accounting for 37.5% of the total 5023 unit 94 sales. 973 R1 100 RS's, 763 R1100 GS's, and 59 R1100 R's were sold in this country and we are all hoping for a even better share of the total market during 95.
While the K series still holds a prominent place in BMW's motorcycle future, it's the new twin that ha s stolen the show with it's broad torque range and Telelever front end. Will the new 95 twins offer significant changes that might keep this snowball of sales rolling out of those Bavarian hills?
Over the years one thing that has never changed abou t BMW is their desire to improve the product and correct any irregularities that may arise. This "quality first" approach is just another reason for the fierce "Brand Loyalty" we owners are known for.
By now many of you know that the clunky transmi ssion, rattling clutch, leaky head, thin handlebar, loose fairing (L only) and surging chip irregularities of the early production R1100 94 models have been, or will be fixed in the 95 models. In each case where a potential problem arose BMW in Germany i mmediately started looking for the cause and a fix, while BMW of N.A. often steadfastly denied that each sequentially reported problem even existed. This is understandable - to a degree - why respond to what could be just rumors if no one at the New Jers ey headquarters has actually seen with their own eyes the supposed problem some customer or dealer is reporting? After all, isn't that what BMW's roving district manager representatives are for - to ascertain what is a "real problem" as contrasted to wha t is most often just a problem in service or procedure.
One condition however, haunted us from late 93 till the end of 94 and it was never discussed very much because nobody seemed to know what was really going on. The mystery condition that baffl ed myself and many others was excess oil consumption in a otherwise perfectly tuned, properly broken in, well cared for, new R1100 bike. What was going on? Some people had a problem while others did not - what gave - what gives? My own experience with oil loss only occurred at sustained high speed but still was so little that I never gave it much thought. Others however, talked in terms of losing a quart in 1000 miles - way out of line for any BMW - much less a brand new one. Complaints to BMWNA were often rebuffed with a standard reply - "You overfilled it", "The rings aren't properly seated yet, give it more time", or the more ubiquitous, "you must not have checked it on level ground". The complaints, were never answered and I'm sure many new owne rs felt like snivelers or that their bike was just "different" from others. Of the 80 responses received from the recent "Oilheads" survey the average oil usage reported was .88 quarts per 2000 miles. The GS owners who responded however, reported 1.46 qu arts per 2000 miles. Average mileage for all 80 units was 11806 miles - plenty of time for break-in to have occurred. Many owners of early production run 94's continued, as I do, to just add oil as needed and we collectively all assume that it's just th e nature of our personal machine.
Not True! We can all be vindicated because the truth is now coming out even though I've never seen any writing about this subject from any source, especially BMW. The early R1100 engines did and do use oil because of a "soft spot" in the original design. More over, this occurs especially at high RPM's and makes any of the early production run units inherently unsuitable for sustained high speed running or track use unless oil is added on a regular basis that is m ore frequent than the average intervals associated with either the K or old R bikes. In new twins produced thru 5/94, oil mist, vapor, bubbles, and fog referred to loosely as "crankcase fumes", all condensate and form droplets on the surface walls of a l abyrinth system which is cast into the top of the block. This reformed oil is fed, via gravity, back into the lower oil cavity. Blow by gases and fumes still remaining after labyrinth contact are sucked via intake manifold pressure thru a black cone shap ed external oil separator in which the last little bit of oil is removed from the gas. This oil is returned to the engine via a separate line while the gas vapor is fed into the air cleaner to be burned up in the engine combustion cycle. A wonderful sys tem that works well - but not well enough. The notion that oil mist would condensate due to contact with aluminum labyrinth walls was over stated in the initial design. What actually happens is that under hot conditions at sustained high RPM the oil mi st is getting past the labyrinth webs and into the external oil separator which becomes overworked thus allowing oil mist as well as gas mist to be sucked into the air cleaner to be burned (used) up during regular combustion. This phenomena explains the slightly excessive oil use reported by many owners with early production run R1100's. As mentioned earlier - BMW always finds the problem and moves to correct it right away - even if they had here-to-fore not acknowledged the existence of the problem to be fixed!
So here it is - a brilliant solution that adds mechanical complexity but now offers us a advanced R1100 engine that has more potential for sustained high speed use while maintaining maximum power at top RPM's. Engines produced from 6/94 o n no longer have a external oil separator that can be overworked at high RPM's but now incorporate a impeller unit that fits on the front end of the lay shaft. BMW refers to this new system as "Rotary Ventilation".
The impeller unit will not retrof it to the older bikes without changing the lay shaft (split cases) so we indeed have a major change here. No one I talked to knew how it worked so the following must be viewed as speculation and could be wrong as to how it works. First, my version as f ollows: The new design incorporates a spinning four lobed piece of thick flat steel (think of a thick disc with four semi-circles cut out at equal distance around its circumference) with a large hole in its center. Holes also extend from the center hol e out to the end of each lobe tip. The whole unit is now fitted on the lay shaft in front of the sprocket. A lip is machined on the front side of the large center hole in the impeller and this now fits and turns snugly in a new seal that is pressed int o the chain case cover. A large external line now runs from the front of the crank chain cover back up to the labyrinth chamber. When the engine turns the four lobes turn also and try to "sling" by centrifugal force anything that's in the four lobe hole s out to freedom in the case cavity. Now here's where things get tricky - think of standing in the yard with a 12' garden hose that's open on both ends. As you sling this around over your head any water that's in it will be slung out quickly - but guess what - so will the existing air! If you keep slinging the hose round and round air begins to be drawn in from the nearly stationary open end near your hands to later exit at the open end that's moving very fast about nine feet out. This is known as pass ive circulation. Daniel Bernoulli, the Swiss Mathematician (1700-1782), accomplished developments in hydrodynamics that delineates the factors at work here. A second force also begins to take effect. Just like when air is blown over a straw that extend s into a liquid - that liquid starts to arise and will come out to atomize in the stream of blown air. The air stream creates a low pressure area over the straw causing the air and liquid in the straw to rise up and move out. This phenomena does not care whether the air is moving and the straw is still or the straw moving and the air is still - movement still occurs. BMW's four wing disc slings, but also acts like 4 straws that have air moving over them - because they are moving. This contributes even m ore to the passive circulation that will draw oil mist from the Labyrinth area. A brilliant step forward for BMW that has never been used on a motorcycle before! As the four wing Impeller spins with the lay shaft it slings oil mist out the four wings an d splats it onto the case walls close by. More oil mist is drawn in thru the hollow front end of the impeller assembly to replace the oil mist just slung out. A large tube runs from a point outside the chain case directly in front of where the new seal is press fitted inside. When the case is fitted this seal flush mounts over the machined lip on the front of the impeller for a air tight fit. The large external tube leads back up to the labyrinth chamber where there is plenty of fresh mist to suck fro m. This circulating action insures that any oil not condensated on the labyrinth walls is drawn back down to the lower engine area and eventually into the oil reservoir (case pan). No gas/oil separator is now needed and what little gas blow-by there act ually is can now be drawn off into the air cleaner thru a one way valve in the traditional way. Bingo - no more oil usage and we have a new engine that will be much more suitable for high RPM track or sustained high speed use than the pre 6/94 units. Ju st one more indicator that BMW is always working for us to make them better. Now if we can just have a new cable set up for the T-bodies to stop constant readjustments and rare "Blip & Flip", plus a click type steering damper for the RS models and perhap s a oil temperature gauge that reads in actual degrees F while we're at it and maybe a forced drain system for the oil cooler so we can know how much oil is in the engine - right away, and lastly a non-military time clock that reads in AM or PM - does BMW need to subtly reinforce a military image?
Another speculative version offered from a highly respected source suggests that the impeller is blowing rather than sucking - this is called timed ventilation. This other source suggest that the spinning four wing unit is housed in a tight case in front of the oil pumps but behind the lay sprocket with slots or holes at fixed intervals along the case walls. When the pistons come from TDC toward the crank (positive case pressure) these knowledgeable sour ces think the four small holes in the impeller wings will align with slots on the rotary case walls there by allowing crank pressure to move in thru the four wings and out towards the labyrinth area. I do not believe this is the way it works but none of us will really know until someone (not me) splits the cases on a new 95 twin or until BMW comes forth with a formal explanation of their own - which is not likely to happen any time soon. By the way - no one in N.J. offered any explanation. Whatever tur ns out to be "the way it works" - we still must acknowledge BMW's effort to bring a simple solution to a complex problem.
It's exactly this type of improvement and commitment to quality that will extend the records sales of the new twin thru the dec ade. Even though "first buyer blues" will occur in the minds of some "early run" owners even they must acknowledge the no compromise effort that BMW is making toward the development of a "perfect twin engine". Understand clearly that only a few owners p er hundred actually make use of the high sustained RPM capabilities of these twins and that most owners of old or new type engines will not even notice the difference. One should note also that the pre 6/94 units "rev faster" than their later brothers be cause of the increased weight of the total lay shaft assembly. I'm keeping my early 94 RSL for this very reason.
We know how fast they'll go but how fast will they stop. As you know the new twins have some of the best brakes ever to be offered on a production motorcycle and not only will they pull you down quickly in the dry but these Brembo units offer wonderful predictability in the wet as well. Do you really need to stop any quicker? After all, one has to be in the thick of it before these st ock units start to fade - even a little bit. But they will fade after repeated hard pull-down from high speed and/or after continuous running thru the downhill twisties. What to do? I started conducting some "shade tree" braking test last November that have involved a number of different pads. The manufactures all seem quite willing to match their pads up with any others but very quickly I began to understand some of the recent changes in the disc pad wars. A relation similar to that of tires may be drawn in which we are often faced with a choice of either high milage with very good handling and medium traction or low milage with excellent handling and maximum traction as in the difference between a Metzler Marathon contrasted with a Metzler MZ2. Th is same dilemma is manifest in our choice of brake pads. I have always been one who believes that very sticky low milage tires are some of the cheapest insurance one can buy and that this logic can and should be extended to brake pad choices when the ove r all safety picture is looked at. Our stock BMW pads are very good, (Brembo front, Textar rear) last a long time, cost a lot, and work well in the wet and dry. These stock units are of the metal particle type. After repeated pull-downs from high speed or hours of mountain down hill "cut & shoot" these units slowly began to heat up and fade. Heat from the disc transfers to the pad material, then to its backing plate, thru to the caliper piston and eventually into the fluid itself. Some of the "sinter ed metal" types (Dunlopad) try and cut down on this heat transfer by coating the back plate with a ceramic thermal carrier to prevent heat leak into the caliper piston and on to the fluid. As brake fluid heats up it gets less effective as a hydraulic flu id. If the surface of the piston gets hot enough small bubbles may form on its fluid side surface and then fade really starts to occur. Both Galfer and EBC have thermal barriers also but theirs is in the form of a Kevlar swatch that is surface glued to the back of the pad plate. These are very effective but cause wheel (disc) drag until they are fully seated in (compressed). The use of Dot 5.1 helps the performance of both "organic" and "sintered metal" types but seems to help the "sintered" metal ty pe the most. Far less heat is transferred to the piston thru the "organic" (Kevlar, carbon powder, etc..) types and this must account for the fade free short braking distances of the Galfer pads when contrasted to the Dunlopad S45 for instance. As the t est continue thru the spring I will compile and publish the full results by mid summer. For now, the EBC's, Ferodo's, or SBS's have not been fully tested, but one clear choice is there for us BMW riders and that is the Galfer Organic pad. This Kevlar, C arbon Powder, Ceramic pad will stop your BMW much faster than the stock pads will, especially from high speeds, and they seem to be fade free. I was able to get the stock pads and the Dunlop pads to show fade by running the bike up to above 125 mph and t hen applying full, front and rear braking. By doing this seven times in quick succession one can quickly ascertain fade as braking distances increase for the "metal particle" types and remain more constant for the "Organic" ones. All of the braking resu lts will be reported in a later issue so please consider these brake comments as inconclusive for now.
Just a few words here about brake fluid. The Dot 5.1 brake juice is being snapped up like free fried chicken by those who can get their hands on it. Lucas/Girling out of England was first and that's what I've converted my R1100RSL ABS to. With a dry boiling point of 530 degrees F this is simply the best you can buy.
Now Ferodo is right there also with it's new 5.1 fluid which it recommends for all racing, high performance, and ABS applications. Ferodo tech told me that racers are changing out their bikes right and left.
Bel Ray is working on theirs also and we'll see it soon - meanwhile just be happy with their new 100% synthetic gea r lube in a 70-90 weight. I used this at the ECTA runs last year and know for sure I had more power to the rear wheel because of it.
I realize after seeing the "speed run" piece in the February issue that I failed to point out the help I received f rom many sources - especially Chris at CC products who donated "free of charge" the dyno tuned pipe system and lots of good back and forth tech exchange. Larry Cann and the boys at BMW of Orlando put up with my loud squeaky voice over the phone and worke d constantly to get me the parts I needed, while offering absolutely first class precision service and tuning. Kari Prager at California BMW provided the "near perfect" Ohlins shocks and solid bar mounts while Bel Ray let us have the 100% synthetic gear oil before it was even released. Many riders and racers called and gave advise on how to keep the bike straight and on the ground while and after coming "out of the hole".
Chris at CC products is working right now to assure I have a even better chan ce to nip the Harley this weekend of April 1st & 2nd. Remember - if you need five horsepower at the rear wheel - call C. C. for a D&D pipe - you won't be sorry.
With respect to all
Jim (Dr. Curve) Roche
P.S.- Galfer pads, Bel-Ray 100% synthetic gear oil, and Dot 5.1 brake fluid are all available right now from BMW of Orlando. Call them at 407/826-4269 and they can ship right away.
Jim(Dr.Curve)Roche jroche@mailer.fsu.edu high performance old twins