RE: [OT] Petrol Pumps ....was Views on X10 Addressing

["Phil Harris" <phillip.harris1@xxxxxxx>]

Are you sure that pinking is caused by the lack of cushioning for the
valves?

My experience has been that pinking is caused by pre-detonation of the
fuel-air mixture and that the lead was added as an aid to running higher
compressions in engines to aid efficiency. Pinking causes burning of the
edge of valves which in turn destroys them and the valve seats...

Phil

> -----Original Message-----
> From: Pedro de Oliveira [mailto:oliveirp@xxxxxxx]
> Sent: 06 September 2001 10:44
> To: 'ukha_d@xxxxxxx'
> Subject: RE: [OT] Petrol Pumps ....was [ukha_d] Views on X10
Addressing
>
>
> Ok - admitably "some" cars need to keep running on leaded
but the vast
> majority (95%) of engines running leaded could use unleaded and have
no
> problems apart from "pinging".  The pinging is caused by the
valves not
> having enough lead deposit to cushion the valve and so
"pinging"
> occurs. If
> the vehicle has been running on leaded for a substantial amount
> of time then
> the change to unleaded would not affect the engine in the slightest
due to
> the lead deposits already existing.  The primary reason for leaded
fuel is
> not to leave lead deposits but this is an effect of running leaded and
as
> such helps us to run unleaded by its own deposits - if that makes
sense.
>
> Pedro de Oliveira
>
>