Edis 4

[AshG]

mine was fine at idle but was glowing red at raised rpm. i had the carbs professionally setup on the dyno at ATSPEED in essex last week and you could clearly see the carbs were quite badly underfueling at raised rpm from the afr read out. now that they are setup the manifold doesnt get half as hot as it did.

i do recall them using a laser thermometer on the manifold a various stages to check the temp.

[Big Vern]

I shouldn't have thought it possible to have 'red' exhaust at idle unless you'e waving an acetylene torch on the exhaust! Simply not enough calorific value at idle to generate that amount of heat...
At full throttle or close too, then most of the heat is due to retarded ignition though some could be due to friction as the hot gases pass over sharp edges inside the exhaust.
Detonation forces ignition values retarded from optimum thus moving end of combustion closer to the opening of the exhaust valve and thus hotter exhaust temp. You can offset this by richening fuel mixture to cool combustion but this is at the expense of fuel ecomony.
A very lean mixture is unlikely to raise exhaust temp. significantly as the combustion gases become too diluted with excess oxygen reducing energy (heat release). Optimal fueling for something like a Zetec would be 13:1 AFR for full power and around 14.5:1 AFR for cruise/ idle. and about half an AFR richer at full power for a Pinto to allow for poorer fuel distribution across the cylinders.

HTH BV.

[AshG]

im looking at my read out from the rr graph these are all at full throttle

the readings on the sheet are every 100rpm but i have only posted every 500rpm.

at 6000rpm my afr was 12.4
5500rpm 12.85
5000rpm 13.08
4500rpm 13.97
4000rpm 13.29
3500rpm 12.44
3000rpm 12.49

on cruise between 2500rpm and 3700rpm the afr ranges between 13.9 and 14.2 idle at 1000rpm is bang on 14.5

looks like they did a pretty good job then. the car did feel like an animal after they did it compared to my pre tune test drive round exeter show ground.

they did a bit more tweeking after these values on the cruse by adjusting the advance in relation to the tps position reading.

will report back on the fuel economy once its legally on the road