Valve Adjustment

[Whip]

How much more difficult is it?

 

 

 

[TEWKS]

No first hand knowledge but it looks fairly easy. A bit of math is involved.

A nice pictorial here.

 

Pat

[dirtrider]

Evening Whip

 

Actually I think it is easier as the valve train is rock solid so there really isn't any guessing on the correct amount of feeler gauge drag.

 

The down side is you will need to have access to the correct shim thickness if one or more of yours is out of spec.

 

The up side is there is now an adjustment RANGE so it doesn't have to be exact.

 

 

 

[Selden]

No first hand knowledge but it looks fairly easy. A bit of math is involved.

A nice pictorial here.

 

Pat

Nice pics. It looks like the hardest part is not dropping the clip that holds the rocker arm in place. I especially like the part with the timing marks facing each other — that pretty much eliminates one of the biggest uncertainties with the old pushrod valve train.

[ragtoplvr]

when I have to remove a E clip an worry about it flying, I get some fine wire. Finer than safety wire. Wire like you find in a bread twist tie. I tie one end to the clip in one of the narrow areas, other end I hold. Never lost a clip that way. Use putting on also, they like to jump then too sometimes

 

Rod

[Geoffster]

When I saw the first photos and description, I imagined it would be easier than a hexhead. Apparently it is, because the shop I used for my bike's 600 mile svc charges less for a camhead than a hexhead.

 

(Someone please correct me if I'm wrong: I believe that on a hexhead, one doesn't inspect clearances, one adjusts clearances -- EVERY TIME. On a camhead, one inspects and only adjusts as necessary.)

 

[Paul Mihalka]

"(Someone please correct me if I'm wrong: I believe that on a hexhead, one doesn't inspect clearances, one adjusts clearances -- EVERY TIME. On a camhead, one inspects and only adjusts as necessary.)"

 

Really on a hex or oilhead you also inspect first, and adjust as needed. You use the feeler gauge and if it's OK, you go to the next valve.

[mos]

Can someone tell me what the exhaust and intake measurement for the feeler gage are?

Mike

[ESokoloff]

It's more like

Can someone tell me what the exhaust and intake gaps are?

You measure the existing gap(s) & if out of range you remove & measure the shim.

You would then replace the shim with the size that will bring the gap back into spec.

 

E-Z peasy.

The hardest part will be to not loose anything.

[mos]

I understand that but what is the specs for the gap's Intake & exhaust?

Thanks

[dirtrider]

I understand that but what is the specs for the gap's Intake & exhaust?

Thanks

 

 

Morning MOS

 

Here are the general specs but I would strongly suggest you call your dealer & have them furnish you the specs for "your" particular motorcycle.

As far as I know these specs are still correct but you just never know if BMW has a current service bulletin that changes something.

 

The clearances for the camhead with engine temp. below 35°C (95°F)

 

intake are: .13 -.23mm, (.005”-.009”)

 

exhaust are .30-.40mm (.012”-.016”)

 

 

THe "spheres" come in .05mm increments (almost .002”)

 

[mos]

DR thanks for the info.

Mike

[lkraus]

Someone please correct me if I'm wrong: I believe that on a hexhead, one doesn't inspect clearances, one adjusts clearances -- EVERY TIME. On a camhead, one inspects and only adjusts as necessary.

 

I suspect that a hexhead has a range of acceptable clearances, probably the same as the camhead engine, but since it CAN be adjusted to a precise value, it IS adjusted to the exact optimimum clearance, instead of "close enough". Which is great for us obsessive cumpulsives!

[SageRider]

...I believe that on a hexhead, one doesn't inspect clearances, one adjusts clearances -- EVERY TIME. On a camhead, one inspects and only adjusts as necessary.)

I can't speak for other hexheads, but on my '06, I have inspected at every service, but have only had to adjust one valve one time. Fantastically more stable than the valves on my prior '99 oilhead.

edit: over 70K miles on the '06.

[tallman]

Sure they didn't slip a flying brick in there?

So cool the new one are working like that.

[lawnchairboy]

michael:

 

seems like every time on my 06, there is zero or one I have to adjust as well, usually exhaust...

 

chris

[ScottT]

I stopped doing the service on my '05... except for the filter. I change it at 6k and leave the Amsoil in for 12k. It's now 12k to do all checks (inspection). I inspect my valves every 24k now and still rarely have to adjust any of them. It's got round about 104k. I would imagine the DOHC motor will stay in spec for almost forever once it's broken in.

[notacop]

Actually my old airheads would need no adjustment if I left them a bit loose. Being too fastidious probably makes for more work. Mt 1100RT-P was the same.

[jviss]

This is the perfect post for the obsessive compulsive engineer, such as I am. I don't even have a camhead, but I'm fascinated with the topic, in particular, the specification tolerance part.

 

What I find interesting is that BMW specifies a range for which there are at least two possible settings using the available shim increments, sometimes three. Consider, for example, that you measure .19mm on an intake valve. You can stay there, or go to .14mm with the available shim, and in either case, be in specification. Or, measure .13mm, and stay, or go to .18mm or to .23mm. What should one do?

 

While it's impossible to get into the BMW designer's head, one might infer that the specification center, or nominal value is .18mm (the middle of the range), and that it came out in print as .13 to .23 when a ±.05mm tolerance was applied. If this is so, one would choose the shim that gets one closest to .18mm.

 

It would be convenient to choose a pair of gauges for both intake and exhaust that tell you which way to go: say on the intake, a .22mm and a .12mm. If the .22 is loose, go one increment tighter. If the .12 won't go, go one increment looser. This, assuming you're never more than one increment off.

 

What are people finding when they adjust these? I don't suppose they get tighter. How loose, more than .05mm?

 

I looked at the SJBMW pics, very nice. This looks like a well designed, easy to adjust system. My CB750 requires a special tool (or judicious use of a screwdriver) to compress the valve spring a bit and slide out the shim. The BMW is much nicer. And, the overhead cam in this arrangement, i.e., no rocker arm per se, but a cam follower pressing directly on the valve stem, similar to a bucket tappet, is a much tighter, and therefor higher performance design than the oilhead. I'm guessing that once they settle in there won't be much adjusting necessary.

[dirtrider]

John the shim tolerance range will become apparent given enough time on the product.

 

So far personally I haven't done enough camheads with enough miles on them to determine a valve setting direction.

 

As a rule on new engines (not specifically BMW boxers) the valve train seat-in wear exceeds the valve to seat recession so valve gap usually opens up slightly.

Then after a number of miles when the valve train components are fully seated in the valve recession exceeds the valve train wear so the valve lash tends to close up slightly.

 

Different riders can experience different valve lash decrease/growth depending on the type of riding they do. Like lots of very high RPM high load usage will usually favor valve recession & lash decrease. Whereas lots of short low RPM runs with many cold starts can favor cam train wear & lash increase.

 

On my KLR I always set the lash to max speciation + next closest shim. (usually a thousandth or two above max specs) as I trash on that engine mercifullyless so they always close up in use. That bike is a pain to set the valve lash as the cams need to be lifted out so setting wide buys me extra time between checks.

 

On the Ducati same thing, always max spec + as that bike gets ridden very hard at very high RPM's & not using valve springs for valve closer doesn't wear the cam & rocker contact much.

 

Even on my BMW boxers (I don't own a camhead) I always set to spec +.001" as on MY bikes ridden the way I ride they close up due to valve recession. That also gives me a bit more wiggle room if I put the valve adjustment off until I am doing another service. (I still like to at least check them at around 10K-12K)

 

As far as where the camhead needs to (or should be) be set to I really don't know yet. That depends on wear traits over miles (if they open up or close up) and how the cam take-up ramps are machined. As long as the valve lift starts somewhere on the cam lobe take-up ramp & is still on the closer take up ramp when closing I doubt it matters one iota where the lash is set as far as engine performance or smoothness as the EFFECTIVE valve opening really isn't effected until the valve lift is well onto the cam's quick lifting part of the lobe & well off of the take up ramp.

 

[macx]

I'd like to know, too.

 

Is the "acceptable range" a similar situation to the others where the dealership won't adjust if it's in that range, but getting the clearances closer to the same will make it run a little better? It's apparently pretty easy to at least do the feeler gauge check. I would like to know how close mine are, not that they're just within "acceptable range."

 

I used to run solid cams in big blocks and, esp on the 426 hemi, a difference of just a couple thou would make a discernible seat of the pants difference in engine response and power.

[jviss]

John the shim tolerance range will become apparent given enough time on the product.

 

So far personally I haven't done enough camheads with enough miles on them to determine a valve setting direction.

 

As a rule on new engines (not specifically BMW boxers) the valve train seat-in wear exceeds the valve to seat recession so valve gap usually opens up slightly.

Then after a number of miles when the valve train components are fully seated in the valve recession exceeds the valve train wear so the valve lash tends to close up slightly.

 

Different riders can experience different valve lash decrease/growth depending on the type of riding they do. Like lots of very high RPM high load usage will usually favor valve recession & lash decrease. Whereas lots of short low RPM runs with many cold starts can favor cam train wear & lash increase.

 

On my KLR I always set the lash to max speciation + next closest shim. (usually a thousandth or two above max specs) as I trash on that engine mercifullyless so they always close up in use. That bike is a pain to set the valve lash as the cams need to be lifted out so setting wide buys me extra time between checks.

 

On the Ducati same thing, always max spec + as that bike gets ridden very hard at very high RPM's & not using valve springs for valve closer doesn't wear the cam & rocker contact much.

 

Even on my BMW boxers (I don't own a camhead) I always set to spec +.001" as on MY bikes ridden the way I ride they close up due to valve recession. That also gives me a bit more wiggle room if I put the valve adjustment off until I am doing another service. (I still like to at least check them at around 10K-12K)

 

As far as where the camhead needs to (or should be) be set to I really don't know yet. That depends on wear traits over miles (if they open up or close up) and how the cam take-up ramps are machined. As long as the valve lift starts somewhere on the cam lobe take-up ramp & is still on the closer take up ramp when closing I doubt it matters one iota where the lash is set as far as engine performance or smoothness as the EFFECTIVE valve opening really isn't effected until the valve lift is well onto the cam's quick lifting part of the lobe & well off of the take up ramp.

That's interesting. I hadn't considered valve recession. Doing a little reading on it, I'm surprised there's much valve recession at all. Is this normal in modern engines, i.e., with hard valve seats, or is it an olihead characteristic, or is it happening to some degree on all engines?

[dirtrider]

Afternoon John

 

Valve recession can happen a bit in all engines that have the valves getting hot then slamming into the seats thousands of times an hour.

 

It isn't a big issue in modern engines with hardened seats & high alloy valves but it doesn't take much with a tapered valve margin into a tapered seat to lose a thousandth or so on the valve lash.

 

[jviss]

Thanks; fascinating. You certainly know a lot on these topics.

 

Oh well, on that note, I went off to the garage to put the 'RT on the lift and adjust the valves.

 

I was amazed that only two of the valves needed any adjustment at all, the top right intake, and the top left exhaust; and even so, they were certainly within the range of the next up or down feeler gauge. I could have left them.

 

This could be an artifact of the way I adjusted them previously, with my old school feeler gauges, but couldn't have been much off. Now I have pairs of Wurth gauges in .15mm and .30mm.

 

 

 

[dirtrider]

Evening John

 

If this is on your 1100RT next time you check them rotate the elephants feet to about 4 different places when you check the lash. I have found some that the elephants foot wears (or is built) with enough variation to get looser or tighter by a thousand or so by just rotating to different clockings.

 

[jviss]

Good idea, thanks. I haven't torqued the valve covers yet, maybe I'll open them up and check.

[w2ge]

semi-off topic for one minute, please..

 

The exhaust valve rockers are towards the "intake,throttle bodies" side? Correct? or... the intake rockers are towards the front of the bike, i.e. exhaust?

[dirtrider]

semi-off topic for one minute, please..

 

The exhaust valve rockers are towards the "intake,throttle bodies" side? Correct? or... the intake rockers are towards the front of the bike, i.e. exhaust?

 

Morning Phil

 

That wouldn't make sense as the rocker arms that open the valves need to be over the valves then open.

 

BOTH intake rocker arms & intake valves are REAR of the spark plug

 

BOTH exhaust rocker arms & exhaust valves are FORWARD of the spark plug.

 

 

[w2ge]

Thanks DR,

 

Kinda what I thought.. but was watching JVB video and I "got" confused..

[Hank in WV]

I just checked the valves on my 2010RT with 8000 mi. The exhaust valves were fine but the intakes were on the tight side. They ranged 007, 006' 005' and 004. Should I change out some semi-spheres or should I be alright for awhile? Are these usually stocked by dealers or do they have to order them?

[dirtrider]

Evening Hank

 

Well that .004" is out of spec so at least do that one.

 

Personally I hate tight valves (especially the exhausts) but even on the intakes personally I would remove & measure what you have to see what you will need. Then call your dealer to see what they have in stock. Maybe they will even trade you one for one.

 

Personally I would move the .004" to .006" & move the .005" to .007" & be done with it.

 

[Hank in WV]

Thanks D.R., never considered switching places. Would it possibly be better to switch 004 with 007 and 006 with 005? Don't Know if that's faulty logic on my part or not.

[BrianM]

Evening Hank

 

Well that .004" is out of spec so at least do that one.

 

Personally I hate tight valves (especially the exhausts) but even on the intakes personally I would remove & measure what you have to see what you will need. Then call your dealer to see what they have in stock. Maybe they will even trade you one for one.

 

Personally I would move the .004" to .006" & move the .005" to .007" & be done with it.

 

Just make sure that you have measured the shims before moving them to make sure the replacement will work.

 

Dirtrider, your last statement seems to read that the shims could be moved without measuring first.

[dirtrider]

Afternoon Brian

 

It is a bit confusing. That isn't the way I meant it to read.

 

More properly phrased & what I meant to say would be:

 

 

"Personally I would INCREASE the .004" to .006" & INCREASE the .005" to .007" & be done with it".

 

 

 

[BrianM]

That makes more sense.

[Hank in WV]

Thanks D.R.

[flienlow]

Maybe I am out of line here, but do these values really need all this maintenance? 6K? 12K? I have had cars that went 200k and never had the valve covers off. Seems like a license for the dealers to fleece us.

-But I could be wrong.

 

[dirtrider]

Afternoon flienlow

 

But did your cars have mechanical valve lifters in them? If you went 200K without a valve adjustment I'm betting your cars had hydraulic lifters in them. Your 1200 not only has mechanical valve rockers but also kind of new design angular cam lobes.

 

On the being fleeced? that is subject to debate.

 

On the newer camheads you really should do the first few valve adjustments as specified by BMW. After about 10-12k you can probably go a bit longer than specified once they wear in & settle down.

 

Also once you get some miles on your engine & determine what direction the valve parts are wearing you can set them to max or min specification so when they do wear they wear towards nominal specs.

 

[Riverdawg]

Another thing to take note of is a "tight" (real tight) exhaust valve can end up being a burnt exhaust valve. The valve transfers heat when closed and if it doesn't close completely because there is not enough clearance, it can overheat. This is happening to some folks with the "new" four stroke outboards that are used to two strokes and don't appreciate the need for valve clearance checks.

[GRB60]

I did the valves on my '11 RT last week @ 6100 miles. All 4 intakes and 1 exhaust valve were at the low end of the spec (tight). I opened them all up. Only had to buy two shims @ $6.21 each. I suspect that a dealer wouldn't have touched any, since they were technically within the specification. Glad I did it myself. By the way, it FEELS FASTER!

[Bruce H]

did the valves on my 2010GSA today, 36K miles. Mine were .381 so within the spec of .3 to .4, (exhaust side). Called the dealer to see if it was too close. He said to check ADVRider for information, dealer only had two shims anyway, So... Ordered shims from MAX BMW. The tag on the bike calls for .305 exhaust clearance, (papers from BMW say .3 to .4) Not sure what the optimum clearance should be but .305 makes the valves more open than what I have so will go with that.

 

If one had a kit of shims to exchange it would be easier but without it seems the old way was faster. At least I would have been done instead of waiting until next week for shims to arrive.

 

Any thoughts?

[GRB60]

My dealer had a box of shims and we were able to find what I needed. We opened ALL the packages, though. I find it tough to believe that, of all the bikes, they've serviced, none needed adjustment. If you want it done right....

[bobbybob]

Just so we'll have a little more data, as to the "movement" of the gap over time (larger or smaller), here are my results at 16K miles on my '10 R12GS. They haven't changed more than .002mm either way from the 6K mile check. So basically they are still the same so I'm only listing the current measurements in mm.

 

Right cyl: ex-top-.356 ex-bot-.356 int-top-.154 int-bot-.154

 

Left cyl: ex-top-.343 ex-bot-.356 int-top-.165 int-bot-.154

 

[6speedTi]

Hello Dirtrider,

I have a 2012RT. You factory clearance specs are still accurate. Just checked my gaps again. Need a couple shims and ordered a few e clips just in case but they are pretty tough clips. I read through this post and learned a bit on camhead valves. Thanks for all your input. BTW do you know the size of the E clip? I want to order the tooling. BMW list a 9-PHR on description thinking it's a 9mm clip. Thanks.

[Don_Eilenberger]

If the parts department doesn't have shims (most don't - ordered as you order them) and you're friendly with the service department, it's worth talking with them. They might be willing to do a swap.

 

Had a chat with a friendly mechanic at the dealer today.. I'd checked mine last week and all of them were within spec. (@12k miles) He said that the shims that come with the bikes from the factory are in smaller increments then the ones that you can order - about 1/2 the step-increment. He saves all the ones he swaps on bikes he adjusts and uses them to adjust his own camheads. He said using the factory ones mixed with the replacement ones from BMW, he can get his valves within 0.001"

 

I'm sure if I asked he'd "loan" me the shims I needed as long as I gave him the shims I was replacing. But we've had a very good friendship for a number of years - something well worth developing if you like to do DIY.