Timing/HES rebuild

[SWB]

Rewired my HES, tested it, and reinstalled. I checked the timing afterwards, and it doesn't sync up. The manual indicates that the test light should "just go out" when the HES plate is turned, marking the correct point of timing. The test light goes on and off about 5 to 10 degrees before the bike is at TDC (based on "O/T" on the timing port). The HES plate cannot be rotated enough left or right to activate the test light at TDC.

 

I locked the flywheel before removing the pully wheel, and marked the HES plate when I removed it. I lined up the pin on the crankshaft with the notch on the pully wheel when I reinstalled the wheel. The flywheel may have moved a bit when I removed and reinstalled the wheel, but if I reinstalled the pully correctly and set the HES plate in line with the reference marks, the timing should be set as it was before I began.

 

Any idea why the timing would be so far off, or how to resolve the problem short of removing the flywheel?

 

Thanks.

[arbee]

I may be wrong but all internal combustion engine timing

sparks are around 6 degrees before TDC to allow for momentum

of the engine as you dont want sparking too late as all the

combustion will be wasted as the piston goes downhill

 

If you believe you havent changed valuable settings assemble it and run the engine

[smiller]

I believe that for some reason the pickup must be moved opposite normal engine rotation to get the HES to trigger under static conditions (not sure why but Mitch explained it in a prior thread), meaning that you need to set the engine at TDC and then move the HES plate back a bit to get the HES to change state, then lock it down.

 

If you still can't get a static timing you could try a quick cross check by using a timing light and observing that the 'S' mark is centered in the window at idle (start with the HES aligned to the index mark you scribed prior to removal, which should get the timing very close if not exactly correct.) If the 'S' mark is centered then your timing is correct and something is wrong with your static timing technique or test box and if you can't get the 'S' mark centered by moving the HES plate (obviously shut the engine off between adjustments for safety) then something may be off mechanically.

[Ken H.]

(obviously shut the engine off between adjustments for safety)

 

Yeah, I want to see some adjust a HES running. Film at 11...

[smiller]

Hey if people will jump in front of stampeding bulls then it's just a short step to adjusting an HES with the engine running...

[SWB]

I believe that for some reason the pickup must be moved opposite normal engine rotation to get the HES to trigger under static conditions (not sure why but Mitch explained it in a prior thread), meaning that you need to set the engine at TDC and then move the HES plate back a bit to get the HES to change state, then lock it down.

 

If you still can't get a static timing you could try a quick cross check by using a timing light and observing that the 'S' mark is centered in the window at idle (start with the HES aligned to the index mark you scribed prior to removal, which should get the timing very close if not exactly correct.) If the 'S' mark is centered then your timing is correct and something is wrong with your static timing technique or test box and if you can't get the 'S' mark centered by moving the HES plate (obviously shut the engine off between adjustments for safety) then something may be off mechanically.

 

Hmmm... "S" for "static"? I've been trying to do this with the "O/T" mark centered in the view port (i.e. at TDC, as I understand from the manual). Should I be doing this with the "S" showing?

 

I haven't used a timing light in 30 years. I think I've still got a timing light in my buddle of inherited tools somewhere. How would I connect it to my BMW to run a strobe test? As I recall for cars, I connected the thing with the red clip to a positive lead (battery or coil), the black to bare metal ground, and the pickup over the primary cylinder plug wire (left cylinder?).

[SWB]

I may be wrong but all internal combustion engine timing

sparks are around 6 degrees before TDC to allow for momentum

of the engine as you dont want sparking too late as all the

combustion will be wasted as the piston goes downhill

 

If you believe you havent changed valuable settings assemble it and run the engine

 

That sounds like what I am seeing. A screw on the HES plate was loose when I pulled it apart. I'm double checking timing and everything else on this bike because it was "BMW maintained" for 50K miles, and now I want the job done right.

[smiller]

Hmmm... "S" for "static"?

No, an 'S' for something-or-other in German probably. The 'S' mark indicates 6 degree initial timing advance which is added by the Motronic, and so this is what you should see at idle. You will not (or should not) see the 'OT' (TDC) mark with a timing light at idle as this is used for static timing only.

[Joe Frickin' Friday]

Rewired my HES, tested it, and reinstalled. I checked the timing afterwards, and it doesn't sync up. The manual indicates that the test light should "just go out" when the HES plate is turned, marking the correct point of timing. The test light goes on and off about 5 to 10 degrees before the bike is at TDC (based on "O/T" on the timing port). The HES plate cannot be rotated enough left or right to activate the test light at TDC.

 

"test light."

 

Is this a traditional timing light, triggered by the actual firing of the spark plug? Or is this the cobbled-together LED test light (instructions for which can be found here, although you'll do just as well with a plain ol' DVM) that triggers directly from the HES? If the former, then it will not trigger exactly at TDC; I think under idle conditions the Motronic shoots for a spark at 6 degrees BTDC.

 

If the latter, then you should see a signal transition exactly at TDC. The signal is all or nothing, with a sharp transition ("edge") between the two when the gap in the trigger cup arrives at or departs from the sensor gap. Given the range of adjustment of the HES baseplate, I expect you'll only be able to get one of these edges, either a rising edge or a falling edge, to occur exactly at TDC. The other edge, IIRC, will occur before TDC (if spinning the engine in the correct direction), and shouldn't be worried about.

[T__]

Be careful if using a timing light at idle.. My old (early) 1100 would trip a timing light with the (S) pretty well centered in the timing hole IF the RPM’s were below 1000.. That was after the initial STATIC non running timing was verified TDC.. Once I pulled the Pink CCP it was slightly different & was not centered anymore at under 1100 RPM’s..

 

My current 1150RT (single spark) will not trip the timing light with the (S) any where near centered even at 800 RPM idle speed & that bike still has the CCP installed..

 

Once you KNOW FOR SURE where your initial TDC static timing is then you can probably use a timing light to verify the (S) position in the timing hole at 1000 RPM’s then refer to that in the future as a quick check.. From the inconsistencies I have seen on my old 1100 & now my 1150 I’m not too sure I would use that (timing light) as the final HES setting for base timing..

 

Twisty

[SWB]

Hmmm... "S" for "static"?

No, an 'S' for something-or-other in German probably. The 'S' mark indicates 6 degree initial timing advance which is added by the Motronic, and so this is what you should see at idle. You will not (or should not) see the 'OT' (TDC) mark with a timing light at idle as this is used for static timing only.

 

I was looking at "OT" for static timing only. Thanks.

[SWB]

"test light."

 

Is this a traditional timing light, triggered by the actual firing of the spark plug? Or is this the cobbled-together LED test light (instructions for which can be found here, although you'll do just as well with a plain ol' DVM) that triggers directly from the HES? If the former, then it will not trigger exactly at TDC; I think under idle conditions the Motronic shoots for a spark at 6 degrees BTDC.

I actually went whole hog and built the pretty little (static) ignition timing box from Dana Hager's design, though I could have run the same test off my DVM (hey .. my leg's still broken, and I've got nothing better to do for ... months). It shows TDC and 180 degrees from TDC.

 

If the latter, then you should see a signal transition exactly at TDC. The signal is all or nothing, with a sharp transition ("edge") between the two when the gap in the trigger cup arrives at or departs from the sensor gap. Given the range of adjustment of the HES baseplate, I expect you'll only be able to get one of these edges, either a rising edge or a falling edge, to occur exactly at TDC. The other edge, IIRC, will occur before TDC (if spinning the engine in the correct direction), and shouldn't be worried about.

 

Both the BMW manual and Dana's direction speak of the light being on just until TDC. Mine is on before, and off by the time TDC arrives, i.e. it seems like the timing is significantly advanced.

 

I think I'm just going to put it back together and cross check while running using a timing light just to be sure.

 

Thanks.

[kiwiaudio]

Awww, Twisty.... Now you've gone and thrown a big ol question mark on the timing light check!

 

And I thought I'd put that issue to bed with mine.

 

You're saying that you see inconsistencies between oilhead vintages and CCP's on those engines ?

 

I had static timed my '98, not with the engine locked at TDC, but by turning the engine backwards until the instant my DVM showed 12Volts and the OT was centralized (the prescribed method). I then ran the engine at 1000 rpm and did indeed need to move the HES to get the "S" centralized.

 

I have always used timing lights throughout my automotive career, and have come to trust them, but the abscence of any clear cut instruction either from the BMW manual, Haynes manual or a call to my dealer, has led me to question this. Evidently, static timing rules with these engines???

 

No one has at any time told me when the "Z" should pop up, and now there is a question of when the "S" should pop up !

[SWB]

Be careful if using a timing light at idle.. My old (early) 1100 would trip a timing light with the (S) pretty well centered in the timing hole IF the RPM’s were below 1000.. That was after the initial STATIC non running timing was verified TDC.. Once I pulled the Pink CCP it was slightly different & was not centered anymore at under 1100 RPM’s..

 

That's encouraging.

 

Well, short of drilling new holes in the HES plate, I'm not going to be able to turn the HES plate enough to get the static light to illuminate before TDC and to trip at TDC. So, I'm screwed on static timing. I'm going to pull the pulley off again to be certain the notch key is properly lined up with the cam shaft, set the HES to the original marks, and start it up. Then I'll cross check with the timing light so that I can sleep better at night.

 

Thanks for the tip(s).

[T__]

Awww, Twisty.... Now you've gone and thrown a big ol question mark on the timing light check!

 

And I thought I'd put that issue to bed with mine.

 

You're saying that you see inconsistencies between oilhead vintages and CCP's on those engines ?

 

I had static timed my '98, not with the engine locked at TDC, but by turning the engine backwards until the instant my DVM showed 12Volts and the OT was centralized (the prescribed method). I then ran the engine at 1000 rpm and did indeed need to move the HES to get the "S" centralized.

 

I have always used timing lights throughout my automotive career, and have come to trust them, but the abscence of any clear cut instruction either from the BMW manual, Haynes manual or a call to my dealer, has led me to question this. Evidently, static timing rules with these engines???

 

No one has at any time told me when the "Z" should pop up, and now there is a question of when the "S" should pop up !

 

 

Mark, I’m not saying to not use the timing light method, I’m just saying I have showed some variance there so do your homework before totally relying on the (S) mark @ under 1000 RPM as a base timing setting..

Personally I would rely more on the static method as a qualified starting point then if the (S) mark lines up at 1000RPM’s all the better.. If the (S) doesn’t line up then you will have to make a determination on what/where the variance lies..

 

I really can’t help you on the (Z) mark as far as when,, but I show the 1150 as having a timing spread of 0-43° so I would presume the (Z) would show up as 43° BTDC at some point in a low engine load high RPM mode (1150 engine).. My guess is; (a pure somewhat educated guess here though) you would show the (Z) at (middle window) --warm engine, high RPM (after the timing doesn’t/won’t advance anymore),, with the stock CCP installed & computer reset.. Below or at sea level MIGHT lower it a bit if the Motronic uses air pressure as altitude compensation..

 

Problem with the 1100/1150 is the computer (Motronic) controls the spark timing anytime the engine is running so it probably bases the spark timing event on everything from oil temp, to air temp, to RPM, to atmospheric pressure, to throttle position, to 02 sensor input, to maybe even computer voltage, & probably even the base map selected by the CCP..

 

Can the running timing be checked & used? Sure, but in MY OPINION only if you know where it should be at any given time based on past history of knowing where it was when correct..

 

Twisty

[Ken H.]

Problem with the 1100/1150 is the computer (Motronic) controls the spark timing anytime the engine is running

And that's the key point. In many cages there is a procedure to put the engine management computer in a 'fixed' stationary timing mode before setting the static timing. We have no such ability on these bikes. Thus we are stuck with a static not running method to locate the HES.

 

This also why I think the HES position is relatively irrelevant. The Motronic (or BMS-K on the hexheads) will dynamically adjust the time as it sees fit.

 

If you put a timing light on any modern cage and do nothing else, the timing bounces all over the place too.

[smiller]

FWIW on my bike (an 1100RT) the 'S' mark is consistently centered in the window at anything close to normal idle speed (with static timing set correctly.) That said, I haven't checked this on other models and I agree that one shouldn't use the results of this method to override a static timing setting since the latter is what the manufacturer recommends. I do think that it is a worthwhile cross-check though and that if the 'S' mark is in the window at idle you are probably at the very least close to correct.

 

I'm not sure what is wrong with your method of checking the static timing or why it's not working for you, but again the index mark you scribed prior to the removal of the HES should get you close if not spot on. If you align to this mark and the 'S' mark shows up in the timing window at idle I would think you are good to go.

[T__]

Problem with the 1100/1150 is the computer (Motronic) controls the spark timing anytime the engine is running

And that's the key point. In many cages there is a procedure to put the engine management computer in a 'fixed' stationary timing mode before setting the static timing. We have no such ability on these bikes. Thus we are stuck with a static not running method to locate the HES.

 

This also why I think the HES position is relatively irrelevant. The Motronic (or BMS-K on the hexheads) will dynamically adjust the time as it sees fit.

 

If you put a timing light on any modern cage and do nothing else, the timing bounces all over the place too.

 

Ken, I have to disagree with you on “HES position is relatively irrelevant”.. The computer can only control the timing when it KNOWS where it is to begin with.. i.e., it can only add or subtract a finite amount from the base setting based on it’s inputs & spark tables.. It’s ONLY reference to where it is (or was) is the HES position to crankshaft position.. I think you must be thinking of some of the modern automobiles that use a knock sensor or firing frequency analyzer system to dynamically position spark based on actual engine reaction..

 

Twisty

[Joe Frickin' Friday]

Ken, I have to disagree with you on “HES position is relatively irrelevant”.. The computer can only control the timing when it KNOWS where it is to begin with.. i.e., it can only add or subtract a finite amount from the base setting based on it’s inputs & spark tables.. It’s ONLY reference to where it is (or was) is the HES position to crankshaft position.. I think you must be thinking of some of the modern automobiles that use a knock sensor or firing frequency analyzer system to dynamically position spark based on actual engine reaction..

 

+1. FWIW the hexhead motor does have a knock sensor(s) on board, but the 1150 and 1100 oilheads do not.

 

Also, the knock sensor only comes into play when there's actual knock; if there's no knock, then the table value is the optimum (MBT) ignition timing. If the HES is maladjusted, then you will not be at MBT spark timing.

[Don_Eilenberger]

+1. FWIW the hexhead motor does have a knock sensor(s) on board, but the 1150 and 1100 oilheads do not.

 

Also, the knock sensor only comes into play when there's actual knock; if there's no knock, then the table value is the optimum (MBT) ignition timing. If the HES is maladjusted, then you will not be at MBT spark timing.

While we're in the wrong forum.. everything I've heard from BMW on the knock-sensor implimentation on the hexheads is that it's doing real-time timing adjustments to optimize power. It's easy to imagine this since the engines have 12:1 compression - almost anything except aviation fuel is going to cause some knock if the ignition isn't adjusting itself continually - meaning the internal maps are probably only used in case of sensor failure or on startup.

 

Supposedly the ECU processor in the hexheads IS fast enough to do that sort of calculation, and correct timing on the next ignition cycle PER cylinder (which is why there are two knock sensors).. The mixture calculations are also apparently real-time, which is why 2 O2 sensors are used - individual cylinder mixture correction is done.

 

Most BMW cars have been doing this for more than a decade now - expecially the ones that use high-compression to maximize the power potential (based on fuel used..)

 

Miracles of modern computing power..

 

What's interesting is - hanging out on the Hexhead forum - there is very little discussion of TB syncing, mixture adjustments or engine vibration. Most talk is about farkles being added and rides taken.

 

Sorry for the drift off-topic here. On Topic - I also haven't heard of any HES failures on hexheads. Might be they fixed the wiring, might be they just don't have enough miles on them yet.

[bmwmick]

Be careful if using a timing light at idle.. My old (early) 1100 would trip a timing light with the (S) pretty well centered in the timing hole IF the RPM’s were below 1000.. That was after the initial STATIC non running timing was verified TDC.. Once I pulled the Pink CCP it was slightly different & was not centered anymore at under 1100 RPM’s..

 

That's encouraging.

 

Well, short of drilling new holes in the HES plate, I'm not going to be able to turn the HES plate enough to get the static light to illuminate before TDC and to trip at TDC. So, I'm screwed on static timing. I'm going to pull the pulley off again to be certain the notch key is properly lined up with the cam shaft, set the HES to the original marks, and start it up. Then I'll cross check with the timing light so that I can sleep better at night.

 

Thanks for the tip(s).

 

Scott,

Since you are using the test box, the TDC LED should be ON as you pass through the window in the timing cup. Turning the engine CW from the front, you should see the LED go OFF as soon as you reach the end of the window.

Did you try pinning the flywheel at TDC using the mandrel? If you did and the HES plate will not move enough to turn the LED OFF, the timing cup is not indexed where it should be.

I've timed a lot of these Oilheds and never had a problem getting the static timing set.

 

Mick

[SWB]

Scott,

Since you are using the test box, the TDC LED should be ON as you pass through the window in the timing cup. Turning the engine CW from the front, you should see the LED go OFF as soon as you reach the end of the window.

What's a timing cup? The port/window I look at to see the timing marks on the flywheel? Or the lower pulley?

The TDC LED is on as I approach TDC (based on observing the flywheel, but goes out prior to hitting the "O/T" mark.

 

Did you try pinning the flywheel at TDC using the mandrel? If you did and the HES plate will not move enough to turn the LED OFF, the timing cup is not indexed where it should be.

 

I used an 8mm bolt to pin the flywheel when I removed the pulley. My son did the work (as I'm mobility-limited), and said that the bolt had shifted, when he went back to remove it. I was initially concerned, but since the pulley position is guaranteed by a notched "key", and I marked the HES against the engine, I reasoned it should not make a difference. The HES is in it's original position (though I'm trying to double check the timing; hence this post), and the pulley is in it's original position. How could I screw this up??!

 

My greatest fear is that I messed up the flywheel when I reinstalled the flywheel, clutch, and transmission. However, it ran fine afterwards, and the flywheel also has a key, so it'd be tough to mess that up as well.

 

What else have I done? I applied the timing chain mod too. If the timing chain was way out of alignment, I guess it could cause this problem.

 

I should have some time tonight. I'm going to retrace my steps and recheck this.

 

Thanks Mick,

 

Scott

 

[Ken H.]

I'm not saying it is totally irrelevant, just not critical to be spot on +/- 0.001 mm or whatever. I've replaced many a HES and as long as I made a mental note of where it came out, position wise, and got it back visually in the same spot, the bike ran fine.

[Ken H.]

I also haven't heard of any HES failures on hexheads.

Because there isn't one! The hexhead uses a more tradition crank shaft position sensor threaded into the block and measuring slots directly on the crank. Many more times per revolution that the oil heads I might add.

[bmwmick]

What's a timing cup? The port/window I look at to see the timing marks on the flywheel? Or the lower pulley?

 

The metal cup on the lower pulley

 

The TDC LED is on as I approach TDC (based on observing the flywheel, but goes out prior to hitting the "O/T" mark.

I used an 8mm bolt to pin the flywheel when I removed the pulley. My son did the work (as I'm mobility-limited), and said that the bolt had shifted, when he went back to remove it. I was initially concerned, but since the pulley position is guaranteed by a notched "key", and I marked the HES against the engine, I reasoned it should not make a difference. The HES is in it's original position (though I'm trying to double check the timing; hence this post), and the pulley is in it's original position. How could I screw this up??!.

 

 

I doubt you screwed it up. Once you do your checks, I'd say just align the screws with the wear marks and consider it done

 

My greatest fear is that I messed up the flywheel when I reinstalled the flywheel, clutch, and transmission. However, it ran fine afterwards, and the flywheel also has a key, so it'd be tough to mess that up as well.

 

No, the flywheel is fine

 

What else have I done? I applied the timing chain mod too. If the timing chain was way out of alignment, I guess it could cause this problem.

 

Nope, it's not the cam chain

 

I should have some time tonight. I'm going to retrace my steps and recheck this.

 

Thanks Mick,

 

Scott

 

Mick

[flars]

When I replaced my HES, I marked the old HES plate and the front of the motor and lined up the marks when I put the new one on. I tried to check the timing and couldn't get it to agree with what I had heard was correct. I just buttoned it up and have had no problems in the 20000 miles since.

[Stan Walker]

Perhaps all of us who contemplate doing this should take the time to "check" the timing before doing any disassembly. That way we would know what it should look like after we put it back together.

 

But perhaps that would take all the "fun" out of it.

 

Stan

[flars]

Of course, if your HES has already failed, trying to check the timing before removing the HES would be difficult unless you had two bikes.

[Stan Walker]

Of course, if your HES has already failed, trying to check the timing before removing the HES would be difficult

 

So true, perhaps if you are the type to work on your own bike, you should check it before it fails.