Valve Maintenance

theMucker

theMucker

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I'm still negotiating to get an R18... availability, "build" parameters, price, etc. But I'm pumped! I'm also reading everything I can about it. As a result, I've learned that it doesn't have hydraulic lifters. The 8 valves require periodic checking and adjustment. It seems to me that it must be VERY easy to do, what with the cylinder heads protruding out so prominently. My old '65 R50/2 was the simplest four stroke engine that I've ever owned or worked on and with a few decades experience as a professional motorcycle mechanic (among other mechanical vehicles and products) I have no concern regarding working on the R18.

If anyone here has done their own valve service, I'd like to hear what you think of it. Pros, cons, easy or challenging.

Hmmmm... I wonder how hard or difficult it is to obtain a OEM service/shop manual in printed or .pdf form. Any good wrench knows that a shop manual is essential, even if it's most useful info are the torque specs. Being one who hates leaving things truly stock, I will likely go INSIDE this great new beast for one reason or another.
 
I had a 2015 R1200R. Boxers are super easy to check valves. The R1200R had shims, but the R18 has tappets; so the R18 might need adjustment more often, but it'll be way easier to perform them.
 
justcharlie said:
I had a 2015 R1200R. Boxers are super easy to check valves. The R1200R had shims, but the R18 has tappets; so the R18 might need adjustment more often, but it'll be way easier to perform them.
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I have every expectation that the R18 will be easy to do valve maintenance. I was hoping to hear personal info from those who have done it. Even with "easy jobs" experienced wrenches will often have interesting anecdotes worth reading.
 
blackx5 said:
With just 400mi, my valves are noisy. Supposed to be that way? I’m a Harley guy. I’m used to noise, but... Anyone else???
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Bmw r18 valve noise

I picked up a new bmw r18 and after getting done with my first ride home, I noticed there's a decent amount of ticking from the valves. It's the same amount and same volume of ticking on both cylinders. I just wanted to know if that's normal?
www.r18forums.com
 
Gaylord Poe said:
I’ve always heard and believe (within an experienced reason) “A noisy valve is a happy valve”
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Valve noise can be a sign of nothing to worry about OR that maintenance is due OR that something is amiss.
Typically, with adjustable tappets, the valve system may exhibit some subdued clatter or whirring sounds. Singles and twins may sound like a clatter or "busy" sound, while the sounds of muli-cylinder engines are more likely to just exhibit a whirring sound because of the frequency of the valve opening & closing events. Think: music drummer, i.e. slow individual strikes are bang-bang-bang, but a drum roll sounds more like "RRRRRRRRRRRRRRRR". [can you do the common French RRRRRR with your tongue?]
As a rule, normal sounds from an adjustable tappet system will not be very prominent, because operational tolerances should be CLOSE to zero lash. What's zero lash mean? It means that there will be very small clearances that must be taken up as valves open & close. True "zero lash" is the virtually unmeasurable clearance between the valve stem and the rocker arm. A fully closed valve will have it's tappets (rocker arms/lifters/valve stems) relaxed so that the valve stem-to-rocker arm clearance will be either ZERO or a very small fraction of an inch. If that "clearance" was in fact zero (measurable) or an interference number, then there is a risk that the valve may not be fully closed (SEALED) when it should be. For that reason, on most pushrod + air cooled engines, we usually set the valve lash between the valve stem and the rocker arm someplace between .001" and .012" depending on whether it's an intake valve or an exhaust valve. Those numbers are the typical specs over a broad range of brands and models. Intake valves usually run smaller than the exhaust side. The exhaust valves are often spec'd out to have more running clearance because they run hotter and, for that reason, we give them a bit more latitude in clearance so they cool well enough during valve overlap.
Typically, valve service procedures are done while the engine crankshaft positioning is placed so each cylinder in question is oriented at Top Dead Center Compression Stroke. I expect that BMW will follow those common methods.
As of this writing, I do not have specs on what BMW recommends for valve maintenance on the R18. Thanks to modern production and metallurgical knowledge, I expect that the specs will be pretty tight. I'm thinking: Intakes @ .001" to .002" and Exhausts @ .002" to .004", each at TDC-C of the particular cylinder. But I may be full of sh*t too! Time and more information will tell the tale.
If the R18 had hydraulic valve adjusters for EACH VALVE (like a common American V8) we wouldn't even be having this conversation. But hydraulic adjusters are HEAVY and having one for each valve adds complexity & costs AND reduces potential RPM. UGH! That's why most high performance engines (car and motorcycle!) still require regular valve system maintenance.

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A well designed & maintained valve system that doesn't run at zero lash can be expected to have a very muted "busy" sound. If it sounds LOUD or as a prominent noise above other engine sounds, it should be checked out and/or compared to other (presumably healthy and well maintained) examples of the same design.
 
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The fit of everything changes a little as things warm up. Valves and pushrods will be a little longer. The aluminum cylinder gets longer also. Aluminum expands more than steel. So in the end, the clearance is needed for a little wiggle room.
My 1976 R75 calls for .006” intake. And .008” for exhaust. The dealer told me to use .004 for the intake.
Dodge slant 6 was .010 and .020”.

I think my R1200R is .05-.012 mm.

I adjusted my R1200R once and it has not needed it again. 74,000 miles.
 
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