Renault 8s 1108cc

[ggcton]

Hi all I am down in spain at present and have had a problem with my 1108 cc 8s basically the same engine as our R4s.
I stripped my head and found the head to be seriously damaged and some damage to the piston nearest the flywheel.
Opinion so far is that this damage has been caused by cheap lower grade fuel causing pre ignition.There is no apparent valve damage but I have not removed the valves yet.
The car is also fitted with electronic ignition which has been said could be contributing if it is faulty.
The lesson might be do not take the chance always add valvemaster + or a similar product to protect the engine.I will take a picture tomorrow unless anyone else has ideas

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[malcolm]

Does the electronic ignition control centrifugal advance?

I found an excellent trick on the Gordini - there was wear in the advance mechanism or springs causing it to pink. Fixed it by bending the little tabs that support the springs and it's brilliant now and doesn't pink. Unfinished page about it on http://www.renault4.co.uk/tech-pinking.htm

It'll be higher speed knock that causes that damage, but the tweek allows the car to run without being so advanced.