Headwork on a cracked head?

[isham-research.freeserve.co.uk at pop.pol.net.uk]

> From the Bentley 1989 - 1991 100,200;

> "Cylinder head, checking for cracks

> When repairing cylinder heads, small cracks in head between valve seats or
> valve seats and spark plug threads (where applicable) are permissable.

> Cylinder heads showing such cracks can be reused without reducing engine
> service life or performance, providing cracks are small.

> a+ 0.5 mm (o.019 in.)

> Cracks in spark plug threads (where applicable) may not be longer than
> through the first coil of threads."

Coil - singular.  See below.

> Included is a diagram showing a crack between valves dimensioned by 'a' and
> NOT extending into the valve seats.

> It would seem that in order for a crack to extend from that location and
> continue through the head it would have to become larger than the specified
> dimension thereby becoming unserviceable (or requiring repair). The 'surface
> crack' translation is probably quite accurate and is defined by the maximum
> dimension above.

Here you see the difficulty that I often have with Bentley.  The
German expression:

     >>>>> .. die ersten Gaenge ..

is plural.  The singular "der Gang" in this context means 'turn', i.e.,
the German text literally means " .. the first turns .. ".  This
plurality is triple-confirmed - the definite article, the noun and the
inflected "ersten" all tell us this is no simple typo.  Don'tcha love a
multiply-redundant language?

There is no diagram in the microfiche - most Germans can read.  It is
said that, during the Cold War, the Russians got hold of an Honest
John missile handbook.  It frightened them witless because it was a
picture book with almost no text.  I remember being mightily insulted
(and saying so) when IBM shipped us some operator manuals about
mainframe card readers containing little cartoons showing how you were
supposed to put cards into the stacker and take them out of the hopper.

Bentley's translations are often crap, as are their wiring diagrams.
They are not alone - the English version of Audi's ur-quattro engine
microfiche has a major error in the discussion of main bearing shell
placement.  Fortunately, they don't physically fit as the microfiche
describes.

> BTW you refer to your 89 turbo quattro avant as a 100 - I assume that you
> are playing sneaky with others on the road and driving a stealthy
> underbadged 200TQA rocket? Bet you didn't change the headlights to the
> non-turbo style ;-)

No, it's a 100TQA.  When Audi introduced the V8 in 1990, they deleted
the 200.  This pissed off a bunch of people (many of them apparently
customers of Gilder Audi in Yorkshire) who had ordered Audi 200TQAs.
Audi substituted V8s for these orders, but that was no use for those who
had ordered Avants because they needed the load space.  So a very
limited number (nobody really knows - between 5 and 20) of Audi 100TQAs
with MC-2 engines was built in RHD form.  Externally, they are
absolutely 100s - including the headlights.  Internally, the seats and
upholstery are 100 but the controls, instruments, and general
functionality are 200.  The 'diesel' badge might be described as
sneaky.

Of course, Audi detuned the engine to 165 bhp.  But there's this guy
over in Portland, OR. ..

--
 Phil Payne
 http://www.isham-research.freeserve.co.uk/quattro
 Phone +44 7785 302803   Fax: +44 7785 309674