Since this motor was deemed to be not convertible I have been putting up with lead replacement petrol, but now that is being phased out and I have looked again into conversion. All the books say 'it can't be done' by which I presume they mean it can't be done by timing adjustment, because there is no timing adjustment on this all electronic system. The spark is derived from a crankshaft position sensor and controlled by the ignition ECU.
Talking to my local spares and repairs shop, they say the problem is that the head does not have valve seat inserts, just seats ground directly into the head. They reckon that it is quite feasible to bore out and fit replaceable seats, for which they reckon in region of £200. This sounds a good bet to me as this is a low milage car, with still only 40K on it, but I'd like a couple of things checked.
1) Timing. I assume moving from leaded/LRP to unleaded would need a retardation. Can this be reprogrammed into the ECU, or can I get away with leaving it as is, given that there is a knock sensor which *should* retard it if knocking occurs?2) How can I be sure the correct seats can be obtained before embarking on taking off the head. i.e. what size are the valves.
3) Will there be enough meat in the head to bore out for replaceable valve seats without hitting waterways or anything else.Any ideas?
Thanks