Valve Adjust

[Duane Ausherman]

It could come from the factory with a loose rocker arm adjustment. Don't bow at the alter of BMW, they are just people and make mistakes.

You are freaking out about nothing. If they were tight by only .001" then you couldn't get the feeler in. Since you have never done it, I would carefully back off the head nuts and retorqe, but only if you know what you are doing and have a beam type wrench.

Set them "your way" as your standard and then check them often, at least every few thousand until you know if they are stable, or not.

Sorry that my article was so poor, or you wouldn't be asking these questions.

[enigmaT120]

GSPD used the adjuster thread pitch, flats and half flats thingy.

That always made me wonder if he was a Triumph guy at some point. It's frequently how I set the valves on my Bonneville, as it's well-nigh impossible to insert a .002" feeler guage into the right spot to test the clearance. That's a flexible little bit of metal.

[Airbear]

I am a (touchy) feeler-gauge person.

Aw Jean, that is so sweet.

Funbags was fond of asserting that nobody else in the universe was capable of using feeler gauges properly. He had had this confirmed 'literally hundreds of times' (I think the number got bigger in longer, more interesting threads).

[rinkydink]

Thanks Duane. Not really freaking out just surprised is all. I do have beam and clicker torque wrenches and will take your sage advice and carefully torque head bolts and see where things are from there. With Issac rolling into Arkansas I certainly have the time before I ride her again.

[Duane Ausherman]

Use the beam wrench to remove the torque too. It should "crack" loose and that number is then not important. If the torque is low, then you will see it with the beam wrench easily. If low, then it won't crack loose, but just turn fairly easily at several lbs low.

[hal]

FWIW here's GSPD's method:


1/12 of a turn (1/2 flat) out from snug is 0.08mm
slightly more than that is fine for the intakes
1/6 of a turn (one flat) out from snug=0.16mm
slightly less than that is 00.15mm about right for exhausts

Running the valves alittle tighter just means more frequent checks.
The tighter the valves, the quieter and smoother it will run.
Tight is not a problem as long as there is some clearance.

[barryh]

In choosing what valve clearances to use it's worth being aware that you are making small but noticeable adjustments to the valve timing and lift. For example in my experience opening up the clearances by 2 thou will incease the idle speed and even make the engine feel a touch more tractable. Mileage goes up by a couple of percent too. It does that because the valve timing is now a couple of degrees milder with less overlap. So at low revs or idle a little less of the incoming mixture is going straight out through the exhaust.

Fixed Valve timing is a compromise, you gain from valve overlap at high revs but lose some potential effeciency at low revs.

These are small efects but in principle if you are a high rev racer tighter clearance will help and if you potter about at lower revs, slightly wider clearances might be best.

[Jean]

Which explains why my idle speed wants to be around 1100 rpm to be smoothest. I also rarely run over 4800 rpm even in 5th gear which is a bit over 70 mph...
I'm using the 0.015 and 0.020 settings. Might try 0.013 and 0.018 sometime when I've got time to readjust idle.

[rinkydink]

OK, the job is done and she is purring like a kitten. Thanks so much for the help....it is an incredible feeling when you successfully do it yourself.

[Jean]

Thank you SO MUCH for final feedback.
sometimes we never hear the results of our advice or insults!!
AND just which settings did you finally decide to use?
Did you find the head bolts loose or properly torqued?