5 cyl interference

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

> Just had a discussion about 5 cyl engine "free wheeling", all
> we know; You cannot crank 20v without the cam belt, but how
> is it with 10v engines? I remember somebody mentioning on
> this list 10v isn`t interference.

> Anybody knows, or can give a link, where to check?

The rule is that there isn't a rule.

Mainly, the solid lifter engines are non-interference and the hydraulic
lifter engines are interference.  The 10V MB engine is definitely an
interference design, as is the MC-2.  I'm not sure about the MC-1 because
one of the changes Audi made was to the cam.

HOWEVER - all WR engines will hand-turn, but I've seen two with VPI
(valve-piston interference) because the timing belt let go or the
crank Woodruff sheared at speed.  They were also both old and worn
engine - which factor is responsible I don't know.

Note that excessive oil pressure can pump up hydraulic lifters to the
point at which the valves don't seal and compression is lost.  There
is a warning in the factory 20V documentation about this, and also a
note saying the engine must not be started within a certain number
of minutes after the cam is put in.  Anyone else actually managed to
do it that fast?  You _really_ have to have your ducks in a row to
get close - every tool laid out and the phone switched off.

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