With leaded fuel disappearing from our forecourts , possibly commencing as early as August this year , I like many others had resigned myself to shelling out about £200 of my hard earned dosh on a Lead Free Head Conversion.

  However after reading an article in a recent Mini Magazine I am having second thoughts on the use of additives, which I had previously discounted after some rather wild claims proclaiming their effectiveness had been disproved.
  Keith Carver , well known in Mini racing circles, conducted a series of tests on both road and race engines over many thousands of miles. The vehicles used were a 2.0 EFI Maestro, an MG Metro and a a 998 c.c. Mini, all of which had not previously been converted to run on unleaded fuel. Engines were rebuilt , run in and tested on rolling roads, then driven for several thousand miles. The heads were then removed, valve seat heights checked, and then re-assembled.
  Four pruducts were selected for evaluation. Others were discounted from the word go as the oils contained in them, to supposedly help with " upper cylinder " lubrication , could not possibly work as the combustion chamber temperature would be far to high for them to offer any protection at all.
Other claims that the products contained chemicals which would phosphide or nitride the relevant  surfaces were also unfounded as the processes required careful monitoring of temperature controls over specific time periods.
   After many thousands of miles testing during which the heads were carefully removed, measured and replaced several times, as well as a great deal of other data being collected one product stood out head and shoulders  above the rest ..............   Red Line Lead Substitute.
It was the only product used that did not show any sign of Seat Recession , or Micro Welding of the valves at any time in any of the cars that used it, not even the race car.
The engine in one race car that had used a product constructed around Potassium chemistry had two totally seized and two partially seized valves. ……….. More