ticking valves or?

[Urban Surfer]

I adjusted my valves, did it three times on the left side before I was sure it was right. I also replaced the cam chain tensioner. The left side is still slightly noisier that the right. Sounds like the valves, and maybe I just didn't get it right. The right side was dead on, no adjustment needed. Will any harm come to it if I ride it, and take it in after a few thousand kilometers?

The bike has 92000 kilometers on it now

Thanks for your help

[enfoman]

You may have to do a valve lash adjustment if they are really loud and not sounding as they should

[Boffin]

There will be no harm done. Did you check the rocker shaft end-float? this often leads to noisy operation - but no harm apart from that.

 

Earplugs help with this kind of issue.

 

Andy

[Tobias]

I would go more on the measurement than the noise. If there is too much clearance there will be some ticking and a little loss in performance. If there is too little clearance there shouldn't be any ticking, but the valves won't fully close and there is risk that they can burn.

If you are confident in your measurement then ride it.

Also note that the throttle bodies can tick as well, you can check this by placing a screwdriver against the throttle body and listening to the handle.

[Galactic Greyhound]

Hi Tobias,

 

That ticking noise from the Throttle Bodies is likely from the Injectors operating from the Motronic fuelling pulses.

 

It's a handy test to make if you think the Motronic may not be getting the HES fuelling pulses or the Injectors are not being operated.

[Peter Parts]

I would go more on the measurement than the noise. If there is too much clearance there will be some ticking and a little loss in performance. xnip

 

More correct to say "change" in performance, not loss. A lot of us think the stock power band with emphasis on high RPM power is truly stupid. And following Lentini's advice, add a few thou to the lash.

 

Contrary to the widely held opinion, I don't find it detectably noisier.

 

Good not to have too much end float.

 

Ben

[Urban Surfer]

Thanks for the advice. Next time it's due for service I'll check the rocker end play. The noise is noticeable only if I put my ear up to the valve covers, one side makes a little more noise that the other.

The bike has to last me for many more years, so I get concerned if something is not right.

[4wheeldog]

Just a reminder......Connected to his use of larger than std clearances or not we will never know, but Mr. Lentini's bike dropped a valve.

 

The risk in running larger clearances is that you may be widening the opening so that the cam follower misses the take up ramp section on the cam. The result being that the valve is hammered open and closed. YMMV.

[Peter Parts]

Just a reminder......Connected to his use of larger than std clearances or not we will never know, but Mr. Lentini's bike dropped a valve.

 

The risk in running larger clearances is that you may be widening the opening so that the cam follower misses the take up ramp section on the cam. The result being that the valve is hammered open and closed. YMMV.

 

Lentini made many experiments - but I thought there's no argument that longer dwell times are healthier for valves. Which is a good reason to add lash in addition to shifting the power band.

 

Not sure about that "hammering" business... especially "hammered" closed. Thinking of something desmodromic or just colorful language?

 

"Misses the take-up ramp," you seem to have a knowledge of Oilhead cam profiles that I have never seen published.

 

Ben

[dirtrider]

Morning

 

On non-hydraulic camshafts there has to be ground in clearance ramps. These include a gentle take-up ramp & a gentle closing ramp. This is not a guess it IS how mechanical cams operate (do the research if you don't believe).

 

The take-up & closing ramps are part of the opening & closing cycle so the valve lash/clearance ramps are part of each others design.

 

If you tighten the valve lash to a point below the cam clearance ramps design you risk valve leakage at both pre lift & post lift due to slightly open valves pre actual "meaningful" lift point. This can cause warped valves, overheated valves, & seat erosion.

 

On the other side- if the valve lash is opened up to above design intent you negate the clearance ramps & risk very harsh valve opening & closings. On a BMW boxer 1100/1150 that can cause the push rods to telescope into the lifter due to very harsh opening as it harshly comes off the base circle onto the flank skipping most of the take-up ramp.

 

On the closing side skipping most of the closing ramp can cause very harsh valve closing slamming the valve into the hot seat & causing accelerated valve recession. It can also cause valve bounce at high RPM's.

 

If you have ever degreed the cam timing & lift points on the BMW boxer you can actually see the opening & closing ramps doing their thing prior to the major lift point.

 

The good news is-- probably a thousandth or two loose is still well within the design spec of most BMW production cams & the clearance ramp design (most operate within a lash range not an exact number).

 

The bad news is-- due to the fact that no meaningful air flow happens until the valves are off their seats a measurable ways opening up the lash a couple of thousandths means little if any USABLE air flow gain.

 

[4wheeldog]

To paraphrase DR, All solid lifter camshaft designs have a take up ramp. Missing it can cause catastrophic failure. Lentini's bike suffered just such a failure.

 

I believe DR explained "Hammering" sufficiently. Desmo valve trains have an entirely different set of oddities.

[Peter Parts]

To paraphrase DR, All solid lifter camshaft designs have a take up ramp. Missing it can cause catastrophic failure. Lentini's bike suffered just such a failure.

 

To paraphrase DR, "The good news is-- probably a thousandth or two loose is still well within the design spec of most BMW production cams & the clearance ramp design (most operate within a lash range not an exact number)."

 

OK, I lied. Not a paraphrase at all. Really a quote.

 

But here we go again, everybody (including me) pontificating about something (like cam profiles).

 

Anybody got the actual data? What the hall is an Internet forum all about?

 

Ben

 

[David R]

.006" intake. .012" exhaust. Cold

 

Its in the manual for my 2000 R1100RT.

 

If you need to put your ear up to the valve cover to tell the difference, there is none. If you got the adjustment right, then just enjoy the bike.

 

Next time you adjust the valve clearance, check the rocker shaft clearance. It could be making noise.

 

David

 

 

I did not want to get in this discussion. If the original poster is asking about getting the clearance right and what could happen if he is off a little then asking him to deviate from the spec he is not sure he can achieve may be a little over the top.

 

In other words, Just because I use 20W 50 does not mean everyone should.

 

Thanks for the advice. Next time it's due for service I'll check the rocker end play. The noise is noticeable only if I put my ear up to the valve covers, one side makes a little more noise that the other.

The bike has to last me for many more years, so I get concerned if something is not right.

 

Apologize if I made this too personal.

[4wheeldog]

To paraphrase DR, All solid lifter camshaft designs have a take up ramp. Missing it can cause catastrophic failure. Lentini's bike suffered just such a failure.

 

To paraphrase DR, "The good news is-- probably a thousandth or two loose is still well within the design spec of most BMW production cams & the clearance ramp design (most operate within a lash range not an exact number)."

 

OK, I lied. Not a paraphrase at all. Really a quote.

 

But here we go again, everybody (including me) pontificating about something (like cam profiles).

 

Anybody got the actual data? What the hall is an Internet forum all about?

 

Ben

 

I am not the one advocating a departure from the engineering decision made be the manufacturer. So, it is not incumbent on me to explain why they made the decisions that they made. I simply pointed out the risk you may be running......Running extra clearance may compromise the follower having the ramp available, causing undo shock to the components.

 

If your valves are noisey when set loose, what you are hearing is the cam hitting the follower, the follower hitting the rocker, and the rocker hitting the valve........All harder than envisioned by the designer, who also participated in deciding what clearance would be appropriate.

 

Again, Lentini's bike dropped a valve. When you go outside the designer's parameters, you do so at your own risk. Good Luck!

[Peter Parts]

The parts are always loose (lash) and always bumping into one another, extra thou or two or not.

 

Let's have some plain talk about Engineering Analysis and Manufacturer's Recommendations, maybe all in caps.

 

Anybody here think "6" and "12" came about from a precise analysis of anything? Sure, the engineers did some calculations (including the cam profiles that nobody here seems to have any detailed knowledge of), figured what kind of new materials they were using, cooling or parts in the worst climates, asked themselves what is the worse idiot doing serving at some dealer (or shade tree) in a far-away non-German country, picked some numbers in metric that sounded kind of easy to remember,... and then they said, "Hey guys... waddaya say to "6" and "12"?"

 

I am not joking*. Although expressed in colorful language, those are the kinds of "engineering" system considerations that resulted in 6 and 12. Not something carried down a mountain by Moses cut in stone.

 

Funny, after 46 seasons with their bikes, I do not idolize the BMW engineers.

 

Ben

*and if they didn't consider ALL those matters, they aren't very good engineers

 

[enfoman]

Good point Peter- After all, they may be taking the KISS assumption into all of this as passed down from the times that these jugs When they were airheads originally, once were designed to be put in a radial position and flown around the world in the day.

[Urban Surfer]

I did have some idea how valves and cams work, certainly more now. What a wealth of information from this board!

Thanks for all the great advice and direction. I'll have a better Idea when the bike is due for service next time around.

[4wheeldog]

You are free to do what you want with your bike.

 

Camshaft design is not as haphazard as you seem to think it is. I have spent enough time with the valve trains of various engines to be aware of what can go wrong. I am in the camp that the decision about the specified clearance was not taken lightly. And I just can't knowingly abuse machinery. Good luck.

[druggrepp]

After setting my valves and sync tb's, I started hearing new tapping on left side.

I replaced chain tensioner, still had noise.

Turned out to be throttle body bushing allowing the TB shaft to slap a bit.

I grabbed it, held it and noise dissapeared.

[Trullion]

Yes, I had to replace the spindle and bushes on mine too; it is a fairly common occurrence if posts on the varoius oilhead fora are anything to go by. It is usually the r/h side one that wears first, possibly because the left one is supported better by the tps? Who knows. It is easy enough to check: simply press against the pulley when the engine is running; if the noise goes there is some wear on the spindle/bushes.

[RPG]

"Funny, after 46 seasons with their bikes, I do not idolize the BMW engineers."

 

Nor do I, but I do appreciate that they make a pretty bulletproof, mostly air-cooled and simple, flat twin motor that has more than stood the test of time.

 

RPG