M10 valve clearance question

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Ro3345
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Sat Apr 07, 2018 9:34 pm

I adjusted my valve clearances today using the rule-of-9 method; With valve 8 at full lift, adjust valve 1, and so on.

All 8 were tight.
I set them all to 0.2mm.
There's an awful lot more noise, but the car runs better.

I'm still not sure if I've adjusted correctly though,

The Haynes manual says;
Set piston 1 to tdc and adjust the valves for cyl 1.

But how can you adjust both valves without turning the crank?

The Haynes manual also lists 0.010" or 0.254mm.
But I've read everywhere else to use 0.080"

Is the haynes manual wrong?
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Brianmoooore
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Sat Apr 07, 2018 11:18 pm

Autodata says 0.2mm/0.008" (not 0.08") cold
Haynes for E21 says 0.15mm-0.2mm/0.006"-0.008" cold.
Haynes E30 says 0.2mm = 0.008" cold and 0.25mm hot

You are adjusting the clearance on the base circle of the cams, directly opposite the lobes. The difference in clearance when adjusting both valves with the relevant piston at TDC of its compression stroke, and when adjusting to the sum of 9 is minimal.
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Ro3345
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Sun Apr 08, 2018 2:47 pm

Thanks for exlaining that. Makes perfect sense.
The sum of 9 method seems overly elaborate in comparison.

Sorry for the typo, I meant to say 0.008".

My Haynes manual "BMW 3&5 series" definitely lists 0.010" cold for 4 cyls and 0.012" for 6cyls.

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