600 mile valve clearances

[Randy_L]

I'm doing the 600 mile service on my '13 R1200RT (using JVB DVD) and have found that my intake valves are right at the tight end of the spectrum. Exhausts are on the tighter end of the spectrum but not right at the end like 3 of the intakes. Couple of questions:

 

1) Like many modern engines, don't intake valves tend to get tighter with use and exhaust valves looser? If so I'll take the time to change spheres now.

 

2) Since I don't have a factory service manual I'm using the data in the and would like to the correct clearances...

INTAKE: .3-.4mm (.012-.016")

EXHAUST: .13-.23mm (.005-.009")

 

Thanks!

[Randy_L]

Follow-up question... wow, Jim sure uses a lot of grease to retain the spheres in the video! Does the hot oil dissolve the grease, or would a smaller amount work just as well. Looks like if you were really careful you wouldn't need grease at all.

[dirtrider]

Afternoon Randy

 

You have your intake & exhaust mixed up. The exhaust are never tighter than the intakes as the exhaust valve stem grows more from exhaust heat than intakes.

 

----below 35°C (95°F)---

 

intake's are: .13 -.23mm, (.005”-.009”)

 

exhaust's are .30-.40mm (.012”-.016”)

 

On a new BMW camhead engines there is really no way to know which way they will wear in. It depends on IF the valve recession exceeds the valve train wear-in. As a rule exhausts recede a bit more so would tighten up but that is not a solid rule.

 

At 600 miles just get them into specs & preferably close to center of specs then run the thing to next service & see where they go.

 

By 2nd or 3rd service they should be where they are going end up & should then stay there for many miles.

 

On the grease thing?- personally I use very little grease as the excess just ends up in the oil filter. Doesn’t take much to hold those little semi-spheres in place. Even thick motor oil will work.

 

[BrianM]

The camhead does not have the first valve adjustment until 6000 mi.

 

I adjusted mine at 6000 mi to the middle of the spec. At 12000 mi they were still in the middle of the spec.

 

Valve clearance

Intake 0.13-0.23 mm

Exhaust 0.30-0.40 mm

[Randy_L]

You have your intake & exhaust mixed up.

Oops, sorry! Thanks for the info.

[Randy_L]

The camhead does not have the first valve adjustment until 6000 mi.

I just feel so much better when I KNOW they are in spec... a happy motor purring along under me. I guess it's just 'peace of mind'.

[racer7]

You're proably just making extra work for yourself. In a few hundred miles there won't be so much wear that anything is going to go much away from how it was built- so unless youreally just want to verify your bike was assembled right, I'd wait a while. Factory tends to be very conservative on its recommendations and didn't pull that 6K number out of the sky..

[dirtrider]

You have your intake & exhaust mixed up.

Oops, sorry! Thanks for the info.

 

Evening Randy

 

You probably should to go back in & re-measure both the intakes (rear valves) & exhausts (front valves). Make darn sure the cam end hash-lines are lined up before checking.

 

Also, make sure the engine temp is COLD when checking. Spec is under (95°F) but I like to check them after all night cool down.

 

On any you find out of desired mid range spec (if you find any out of spec) you will then need to remove the semi-sphere & mike it for size (size should also be marked on the sphere but personally I mike them just to be sure) so you know what size(s) to order. They should come in .05mm increments.

 

Sometimes you can move the ones you have around to get all but one or two valves close then just order the ones you still need.

 

In any case-- start a file (either paper or on your computer) to keep track of INITIAL measurements, what was done (size wise), NEW (after new sphere install) & where what size was installed so you can keep track of future movement & wear.

 

[terryofperry]

Randy

 

You can also download this calculator and/or use it online.

 

http://www.advrider.com/forums/showthread.php?t=670668&highlight=camhead+shims

 

Terry

[Beech]

 

They should come in .05mm increments.

 

Sometimes you can move the ones you have around to get all but one or two valves close then just order the ones you still need.

 

Have found shims in .025mm increments from the factory but not listed on dealer parts lists. So be careful.