Mazda rotaries. Pre mix and octane reduction

[Chris Wilson]

Speaking specifically of 3rd gen Mazda RX-7 rotary turbo engines with oil
metering pump removed and an oil/petrol pre mix used for lubrication of
rotors and seals, how does this affect octane? I had always believed oil
contamination of the fuel reduced it's anti knock abilities, but
carrying this to a logical conclusion 2 strokes using pre mix must
really be hit by reduced octane when they run a high percentage of oil
in the fuel? Or have I got this all round my head?

The real reason for my question is i want to run after market ECU on my
3rd Gen RX-7, and the stock ECU controls the oil metering. Some
knowledgeable people say run the purely mechanical metering pump from an
earlier engine, some say remove it altogether and run a pre mix
oil/fuel like a basic 2 stroke. The car will mainly be used on road race
tracks. Mixing fuel/oil is something I could live with.

Opinions? Thanks.

-- 
Best regards,
           Chris Wilson                          mailto:chris at formula3.freeserve.co.uk
                                     http://www.formula3.freeserve.co.uk

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