Thread: leaded gas help

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For pre-1992 cars designed to run on leaded petrol there are two possible problems if they are to be run on premium unleaded.

Firstly, there will be a loss of about two 'octane numbers' from the older four-star leaded and the LRP that replaced it. This will generally be barely noticed although ignition timing might have to be reset to avoid any tendency to detonation (or 'pinking').

Secondly, if the engine has valve seats cut directly into a cast-iron cylinder head or block, the loss of the protective effect of the lead compounds means that under conditions of hard, high-speed use, erosion of the seats can occur.
If the seats recede by more than the pre-set valve clearances, the valves will overheat and severe damage will result.
The long-term answer is to have hard-alloy valve seat inserts installed.


But if ya really got to have it, I believe this is the ONLY lead additive out there http://www.batterystuff.com/fuel/lea...supreme130.htm