Gads Spark attack-decay + Dreams

[Andrew W. Macfadyen]

I am new to this mailing list and this thread so I must first aplogise in case
I have missed something important.
>From what you have said about sensitivity to advance.I suspect that your engine
may produce a lot more power if the head was reworked to give more swirl in the
combustion chamber.
Going  back to basic theory;  spark advance is really a way of allowing the
engine time to burn its fuel. Ideally a petrol engine should burn all the
fuel-air mixture in the combustion chamber as its pass over TDC if this were
possible it would be nearer an ideal constant volume cycle.   The time taken
for combustion is pretty constant  and can be translated in to crankshaft
degrees for a giving rotational speed but is effected by the ammount of mixing
and turbulence in the combustion chamber  ---- engines with a turbulent swirl
in the combustion chamber durring ignition burn fuel quickly and limmited by
pinking/knock  and other mechanical considerations.  Speed up the combustion
and you should need less advance and get more power with a reduction in
pinging.

Espen Hilde wrote:

> I dont have that much expiriance from dyno runs , but I have seen 5%
> increase in hp for 1degree more advance at max torque.In fact I had to trow
> away 10hp because the engine would start to ping under acceleration but not
> in steady load.
> I think the engine needs max timing near the limmit as possible to develop
> max hp
> at high torque,at low rpm and high when the cylinder filling is not that
> good I would use the minimun advance ,best torque ,approche.
> ps. I just dream of what ion could do for reability in Offshore
> racing.......
> Could the ion system add injector time for a given percentage of the
> injector time used at ping situation?To be a add on system that can measure
> and react to input.
> A warning light to tell when ion is measured, and display what millisec the
> engine
> needed to stop detonating.Or subtract advance and display what subtraction
> that
> was needed to stop detonating at a certain point.Then we had figures to put
> into the timing /fuel computer tables.
> I dont know anything about how this can be done....
> think about it...an EGOR that you can adjust seeking for a certain air fuel
> ratio.
> When the air fuel ratio is not like expected the EGOR with a dedicated
> injector
> driver and computer adds or subtracts injector on time directly to the
> injector.
> and displays or stores the correction somewhere.Then burn a new prom with
> the
> corrections from ion and EGOR.Into junkjard 747computer. It shuld be spot
> on
> first time?Offcurse we had to seek for max hp in high rpm aria with spark
> advance.
> Espen
>  69 NSU 1000TT (1900ccm Turbo engine,640kg car)(german mini corvair)
> Motion 25 cat 2¤2.5 efi
> Gilbert 22 - 225 Yamaha