Type Of Fuel? Help

[chris1986 1]

i've a 1.6l no cat, and just have a few questions, if i were to use the super unleaded petrol how do you know when you adjust the ignition timing to get the most from the fuel? also for the first time i open the bonnet, and was quite amazed to see the manifold was red hot, is this normal for 205? just got mine on the road and loving it, just don't feel its at its maximum, all has good compression and the like.

ta for help

p.s have tried searching but could not find exaclty what i want

[Richie-Van-GTi 74 2 Cars]

fill it full of super, set the dizzy to centre and go for a spin, if it pinks then retard it a touch and try again. Afraid its trial and error to get it just right. Dont forget you will have to set up the idle again if you adjust the ignition timing.

[Faz85 0]

If the exhaust manifold is glowing, your fuel mix is probably too rich resulting in increased temperature. It could also have something to do with incomplete combustion caused by your ignition advance. Stick in some Shell V Power and set the ignition timing as said by Richie.

[jim21070 2]

If the exhaust manifold is glowing, your fuel mix is probably too rich resulting in increased temperature.

 

A rich mixture usually acts as a combustion coolant. Many turbo motors deliberately overfuel to take advantage of the cooling effects of a rich mixture.

 

A glowing exhaust manifold is usually caused by retarded ignition timing and/or a weak mixture. Running high octane fuel will appear to retard ignition timing because it burns more slowly and thus is less susceptable to detonation (pinking). A weak mixture burns more slowly, leading to the same effect as retarded timing.

 

The red hot manifold comes about because fuel is still burning in a cylinder when the exhaust valve opens and carries on burning in the manifold. It follows therefore that a red-hot manifold can also be caused by advanced valve timing allowing the extahust valves to open too early. Check the cam timing is right if the problem persists after checking ignition timing and mixture ratio.

Edited November 5, 2006 by jim21070

[Grim.Badger 15]

First run a couple of tanks of super through, then:

Loosen the studs on the dizzy very slightly, start the car and bring it up to temperature, then with a thick pair of gloves turn the dizzy until it starts to pink (should be obvious) and then turn the dizzy back slightly. Then stop the engine and tighten up the studs again. I did this with a cold engine so it's not as advanced as it could be, but I did it with 99ron so hopefully it will still take 97ron, I've not tried yet though.