Re: old design was oilheads-digest V1 #47

[BAnder6125@xxxxxxx]

In a message dated 1/5/04 10:07:16 AM, cliddell@xxxxxxxxxx writes:


> The bucket and shim and similar designs end up putting side thrust on the
> valve stem itself, with obvious ill effect.   Also, once having measured
all
> the clearances, and referred to the tables for the correction shim in each
> position then you have to dismantle and remove the camshaft to actually
> change them.
>

Actually, The inverted bucket and shim design places zero side thrust on the
valve stem and this is but one reason it is used in all superbike engines.
For a DIY'er, checking BMW valves is no big deal, and mine have held
tolerance for the last 20K mi. For the non-adventurous who rely on a dealer to
do
service, pulling cams every 90 to 120K mi may actually cost less than 6 K mi.
adjustments, especially if you own a Ducati!
I've had BMWs for the last 28 years and love the feel and sound of the boxer
twin (I had an early '77RS and a '78 Belgian Police RS both with 40 mm
exhausts - none sounded better), but the latest iteration engine is part
modern and
part band-aided IMO, mostly due to the basic design (boxer twin) not being
amenable to modern needs of HP, emissions, and maintenance.

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