Espen's Reed Valves

[Bruce Plecan]

> Bruce:
>     You wrote:
> >What application is folks talking about?.
> >F1 or motorcycles?.
> >Big Problem with the reeds is do to inertia the basiclly stay open at
> more
> >than 2,000 rpm, in say a Yamahahah 350 2 stroke motorcycle.  They
> will stop
> >reversion at low speed but not at higher speeds
> >Bruce
> Let me point out that in a 4 cycle engine reversion is only a problem
> at low RPM .... that RPM depends on camming and the inertia of the air
> column in the intake (intake design).  A properly designed reed valve
> that stayed open above a specific RPM might therefore be a real asset
> in a 4 cycle engine.   H.W.

Reversion can happen at many different rpm levels.  Manifolding has alot to
do with it, a dual plane V-8 is about impossible.  Single planes get worse.
Independent runners can be a PITA.
Take something like a Fiat X1/9 engine and hang some 45 DCOEs on it.
Due to the manifolding the runners are kinda long so the Air horns get to be
real short.  So the reversion, pushes the fuel into stand off very easily.
You could slowly rev the engine and watch the stand off start and stop.  It
had 3 ranges as I recall (This was a healthy one that ran to 8,500rpm).