Hi Naudet,
>Just imagine how "dirty and hot" the ignition process must have been to have such an effect on the sparkplugs.
"Dirty" is not quite the right word.
MW50 actually helped to control the ignition process and as an anti-detonant enabled the engine to run closer to the theoretic optimum of the fuel-to-air ratio. (That means it runs weak, not rich. Rich mixtures lead to incomplete combustion, so they could be considered "dirty".)
Specific fuel consumption (fuel spent per HP per hour) actually could be better on MW50 than without. As this happened at very high power settings, the engine ate up a lot of fuel quickly, but it did so economically :-)
The heat buildup is not due to MW50, but due to the high power generated in the engine. If it were possible to run the engine at the same power without MW50, it would be even hotter. (This is interesting for the MW50 vs. C3 injection comparison.)
Regards,
Henning (HoHun)