Ideal air-fuel ratio ?

[66S]

Longman split 45 Webers and full race spec engine with 5 port head, what do you reckon the ideal ratio would be. I seem to recall Vizard saying 12.7 was about ideal for an A series.

Regards
Al

[Smiffy]

12.7 would be ok at flat out/full throttle, i.e. when your putting the engine under maximum load. But obviously you don't want it that rich for general driving or at idle, aim for around 15.5 - 16 when driving on a light throttle.

[66S]

Hi Smiffy,
This is a full race engine so light throttle applications are minimal. That being the case, are you saying the 12.7 is pretty good?

Thanks and regards
Al

[Smiffy]

Yes, when setting up I aim for around 12.5 at full throttle/flat out.

[John Bull]

I like to keep it under 13 when hammering it too.