On aircraft (radial engines) , we used to use an ADI mixture (anti detonate injection) It was an alcohol injection that was used on full power on take-off to cool the cylinders under a heavy load. This was on refuelers that might have a full load of refueling fuel (think JP-4) Perhaps you're getting the same effect!
![Hmm](images/smilies/smiley_emoticons_confused.gif)
Irish
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