Hmm- I re calculated the petrol consumption and it actually is just the same as it was before, only the petrol prices went up since.
There is not such a huge difference between the 531 and the 530 head, the biggest difference being on the very upper end of the refs.
I identified, that at the bottom of all of my problems lately was a heat problem, -- insufficient cooling. So I replaced the oil-water heat exchanger with a proper oil cooler system.
Furthermore, the fresh air supply to the engine compartment was lacking, so I redesigned the engine under tray. I also removed the air conditioning completely with the effect, that my inter cooler works much better. the left side never gets warm. And I painted my 710 engine cover, -- these older alloy ones never leak (unlike the newer type)
I re routed the ignition cables, and tidied up a few more things.
The result is, that there is no more pinging, and the engine runs really nice.
