Advance timing by 3 degrees

[jduke]

I found this article by Rob Lentini while looking for something else.
Anyone care to comment on if this looks worthwhile? It looks like a pretty easy way to pickup some midrange. Does this even pertain to our bikes?



Advanced Ignition Timing - Rob Lentini
Most manufacturers set the ignition timing for the typical vehicle with poor fuel quality in mind. Modest performance gains may be achieved by REASONABLE increases in initial advance. Just like my K75S, the R1100 is no exception.
Assuming you are NOT experiencing ANY pinging or detonation, you can easily advance the ignition timing by about 3 degrees. Here's how to do it:
- Remove the small rubber timing hole cover on the clutch bellhousing (just inside the right throttle body).
- Remove the black cover on the front of the engine. This covers the alternator drive pulleys/belt.
- Notice on the lower (crankshaft) pulley that the three timing plate securing screws are exposed, and that the timing plate (which the Hall transmitters are mounted on) can slide CW and CCW in three slotted holes.
- Put the tranny in 5th gear and, while observing the flywheel with a good flashlight, move the rear wheel to rotate the engine. You will be looking for "OT" (top dead center), "Z" (full advance) and "S" (the 6 degree initial advance mark).
- Warm the engine and observe, with a timing light, where initial advance is taking place. With the engine at 1000 RPM or less, the advance will be very close to "S". Turn off the motor, loosen the three screws holding the Hall transmitter plate, and tap the plate in a CCW direction from the front to the end of slot travel. Tighten down the three screws and recheck the timing. Be SURE the idle RPM is 1000 or less! If your R1100 is like mine, the timing will be advanced 50% further than the "OT" to "S" mark, for about 9 degrees of initial advance. If so, put everything back together and, if during your test ride you detect no noticeable detonation, you are in business. I recommend only Premium fuel if the ignition is advanced. Never use less than the BMW-recommended Mid grade fuel if the ignition is not advanced.

[markjenn]

This might be something to fiddle with but I find the author's cavalier attitude towards detonation off-putting. He recommends bumping the timing up an arbitrary amount and if it doesn't ping during a test ride, you're good to go. IMHO, that's an irresponsible way to represent the tradeoffs of advancing the ignition timing beyond stock.

An engines octane appetite is highly dependent on a variety of factors that the rider can't control. An engine that doesn't ping during a 15-minute test ride around the neighborhood could easily hole a piston in five minutes the first time you head up a steep grade on a hot day with your wife on the back. And in my experience, R1100's need all the octane they can get - many (most?) will ping even on premium in hot weather under high loads. Lots of owners complain of pinging problems.

I have also heard that BMW ECU's have an ignition timing "trimming" mechanism where under steady state conditions, the timing is automatically advanced a small amount with the idea that under steady state conditions, you can afford a little more advance without danger. This is another variable that probably would never show up in a test ride.

I also note a factual error at least for the R110S: BMW doesn't recommend "mid-grade" - the spec for US bikes is premium 95-RON/85-MON which is generally 91 pump or higher. I had thought that all the R1100/1150's required premium, but perhaps the lower-tune models allow mid-grade.

Again, fooling around with trying different advances might be something to try on your individual engine to assess the tradeoffs, but you need to be careful and understand you're using up some of your safety factor.

- Mark

[JonyRR]

on this one, I totally agree with MJ.
BTW, I HAVE tried my timing all over the board, advance AND retard-wise, and always end up going back to OEM.
advanced timing COULD yield benefits IN CONJUNCTION with other mods, including a PCIII or something similar that would keep the overall and specific-RPM A/F mixture at the correct range.
try it...but don't just LISTEN for detonaion, LOOK for it as well via the condition of the spark plugs. (go find the classic NGK poster for this is you don't know what to look for).

[pmc847]

I tried advancing the timing on my 03 BCR but had to go back to oem because of pinging and the 03 defiantly needed premium fuel.

I've advanced the timing about 3 degrees on my 04 BCR and run midgrade. I can also use regular with no ill effects. I think the twin spark motor is a lot more tolerant when it comes to advancing the timing a bit. All that and 220 psi cranking pressure (calculated 12.3 CR).

Yes, the motor did go boom but according to Chris Hodgson the problem was caused by a broken exhaust valve. He surmised the exhaust valve failed because possible when the seats were ground for the new valves they were not ground concentric with the valve guides. He claims that some of the new fangled valve grinding tools just don't do a very good job.

Philip

[JonyRR]

'He claims that some of the new fangled valve grinding tools just don't do a very good job.'

Phil; who did the heads as far as cutting seats?
did they use a NuWay cutter or something else?

[pmc847]

Motorcycle Performance I don't know what machine he used, he just said it was the best. I need to find out.

Again, this is just speculation on what caused the problem but all indications are that it wasn't a clearance or cam chain tensioner not a lean condition.

Philip

[JonyRR]

Phil;
It happens. you can't NOT break something occasionally..helll, it could have been a defective-from-new part.
those manley valves that are supposed to be 'the best'?
my bud had the same thing happen (pulled an exhaust valve head off the stem) in his very spendy single-stick honda 750 motor back when.
uuuuggggglllly, heartbreaking and expensive.
sorry to hear of your misfortune...up until then, it souonded VERY like it was verrrryyy healthy!
over 200PSI cranking compression? I'd take that any day!

[pmc847]

I expect that when I complete the rebuild it will be as health or better. I would really like to break into 100hp plus. I think with Chris's help I'll get there.

Thanks to all for your interest and encouragement in my projects. This is a great board and I know you all feel my pain.

Philip
"It's a great bike but I can make it better".

04 R1100S BCR # 195
03 R1100S BCR #44 R.I.P. new home with 'onekiwi'
Adjustable cam sprockets
Milled heads .025
Larger Valves +2mm intake & Exhaust
Ported and polished heads (just a little)
SJBMW Exhaust Accelerator Kit (modified)
Laser Exhaust
InDuct
SJ PowerFilter
Laser 2 spark Chip
K's 3.5 bar regulator
Ohlins
Sargant Seat
Throttle bodies matched to rubber mounts matched to heads
Throttle bodies venture steps smoothed out.
Exhaust pipe welds ground down
Spiegler SS Brake Lines
LED tail/stop light and turn signals
Aux Fuel Tank (6.8 gallons total)

[boxercup]

Originally posted by jduke
I found this article by Rob Lentini while looking for something else.
Anyone care to comment on if this looks worthwhile? It looks like a pretty easy way to pickup some midrange. Does this even pertain to our bikes?

What would +3 degrees do? Remember this is Linear across the entire RPM band. Jeesh!

Why not have Rap Cat tune our bikes!

( This is of no disrespect to Rob Lentini! )

[signit98]

Originally posted by boxercup


( This is of no disrespect to Rob Lentini! )

...I don't think that Rob Lentini will take it as such... it is my understanding that (as a loss to the BMW community) he has passed away!

[jduke]

9/11/2004.

[jduke]

Rob would never be offended if we're talking about improving R1100's.

But a question, other than the amount of advance, what's the difference in Lennie's cam advance sprockets and advancing the timing?

[throttlemeister]

Originally posted by markjenn
I also note a factual error at least for the R110S: BMW doesn't recommend "mid-grade" - the spec for US bikes is premium 95-RON/85-MON which is generally 91 pump or higher. I had thought that all the R1100/1150's required premium, but perhaps the lower-tune models allow mid-grade.

Please correct me if I am wrong but:
95RON is EU type fuel designation aka regular here and the lowest available. Premium is 98RON.
85MON is US type fuel designation. Given that you can get (from memory) 87MON, 91MON and 93MON, doesn't that mean you can feed the cheapest stuff you can get? I mean, if 85 is required, why feed it 91. It should not ping running 87.

Originally posted by pmc847 He claims that some of the new fangled valve grinding tools just don't do a very good job.

Whatever happened with a wooden stick with a sucktion cup at the end, two hands and a little time? I grinded my own valves when I did an engine overhaul of my old CB650. They prepped the seats with a machine, but I did the final grinding myself. It's a bit of a tedious job and a little time consuming, but like most things you do with your hands it is also very rewarding.

Damn, I am just realizing I am starting to sound like my dad! Must be getting old.

[throttlemeister]

Quick correction on myself, after a little google:

RON    MON    PON 
90      83       86.6 
92      85       88.5 
95      87       91 
96      88       92 
98      90       94 
100     91.5     95.8 
105     95       100 
110     99       104.5

EU = RON
US = PON

[pmc847]

I did hand lap the valves after the new seats were cut for the larger valves. The cause of the disaster is just speculation and we probably will never know for sure. Like JonyRR said, it could have been a defective valve, one in a million. It's just the price you pay (ouch) to have fun.

Philip

[JonyRR]

Phil, if you don't break a part or two you aren't trying hard enough.
At least you're walking the walk here while most of us (myself included) blather about doing it.
I have told myself when this engine turns 60K I'm going to throw the book at it for real...and you will have broken a bunch of ground I'll be looking to cover. Gots me a book on how to build a flow bench.
I'm very interested to sww what a 1200 crank will add to the mix. Keep us posted!
maybe even a motec (spendy) or a holley 950 commander CPU for total control of BOTH A/F and ignition timing?

[pmc847]

Talking about a 1200 crank, do you have one or know where to get one?

Thanks for you interest, encouragement and kind words. It's been a fun project, a little more expensive that I thought but non the less fun and rewarding.

By the way, the right con rod is noticeably twisted. I'll take some pics but not sure if it will show.

Philip

[JayDee1942]

I am using the new PJI units in my R1100S - there is the necessity to retard the ign by some 3 deg.
As it is the crap vibes at 4K are eliminated but you can feel thet the motor is too far advanced i.e. 'feels hard'

[Groceryrun]

Hi JayDee1942 :

Pulse Jet Ignition -
Pulse-jet Ignition - Online

Do you have any affiliation with this company ?
I'm asking because , if you do, you might be a good source of info on the product.