RE: S4 valve clatter

["Peter L. Krause" <pkrause@xxxxxxxxxxxxx>]

We service around three dozen S4 Spiders and have intimate experience with
the "excessive" valve clatter observed. I say intimate because when my
significant other (before she was my significant other) bought an S4 Spider
from me in 1993, she complained about this. All I can say is after long
hours and much money spent investigating this phenomena, the only cause I
can find is the ramp angle on the inlet camshaft (2mm greater lift than
earlier 4 cylinder cars) may be a contributing factor.

In fact, every S4 Spider that we work on exhibits substantially more valve
clatter than the earlier cars. Valve jobs, guide replacement (and I cannot
concur that these cars have more short lived guide or valve life than any
other in the model range) and numerous valve adjustments make no difference.
Live with it! It's not hurting anything.

Seems to me when I was starting out twenty-five years ago, Don Sanders and
others pointed out to me a similar occurrence with cars having Veloce cams
over cars with Normale cams. Our shop did many "upgrades" to used 1600
Veloce cams on lesser models and we always noticed a similar increase in
similar noise to that exhibited by S4 Spiders. At the heel of the lobe,
there is a step between the base circle and the lobe on the Veloce cams,
there may be the same on the Motronic Spider intake cam as well, but I
haven't gone looking for it...

Happy hunting!

-Peter Krause
www.krauseandengland.com
(Headed to VIR this weekend to watch a 6C-1750 Supercharged Zagato and an
8C-2600 tear up the track!)
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided