piston for mc engine

[Phil@isham-research.demon.co.uk (Phil Payne)]

In message <01bd1768$e25faac0$8c111ba1@ktn.olsy.dk> thyrsted@olsy.dk (Kenn Thyrsted Nielsen) writes:

> How come ?

Don't know exactly.  It seems to be an accepted fact, though.  I had
a long chat with Martin at BR Motorsport about tuning MB engines, and
he said melting #5 was the most common problem if the mixture isn't
sorted out correctly.  When Aelred was perfecting the Dialynx manifold,
he discovered that #4 and especially #5 burn hotter than the others -
this was what caused early Dialynx manifolds to warp like wet boards.
Audi's manifold is slightly thicker outside #5.

> Hasn't it got one injector per cyl ?

'One injector in close proximity to the inlet of each cylinder' would
be a better way to put it - both K-Jetronic (CIS) and Motronic (EFI)
systems spray at the inlet port, not directly inside the cylinder.
With CIS, the injector is spraying cheerfully away during the entire
induction/compression/power/exhaust cycle - only during the inlet
phase is the fuel sucked out of the manifold.  True, the pressure
differential is greater at the injector nozzle during the inlet phase,
but I don't think that makes much difference.  There's a fair amount
of swirling about going on.

--
 Phil Payne
 phil@isham-research.demon.co.uk
 Phone: +44 385302803  Fax: +44 1536723021