Fastest prop plane of the war

An important, not very well known advantage for the Allies. For us, standard "aviation gas" was 100 octane. For our opponents, a special high-performance model aircraft might use 96.

Jimmy Doolittle encouraged the develpment of 100 octane fuel in the 1930s.

 

Unfortunately it's a bit more complicated than that from what I recall. I think that there were several methods of determing octane ratings at the time. Again from what I recall, the German system resulted in a lower rating of the same fuel. Engine tuning was as critical as octane or perhaps even more so from what I recall of previous discussions which points to the impact of ground crews and their training as well.

 

...but what we were putting in our tanks and trucks by June 6th 1944 was MT80....80-octane Pool....and earlier in the war it had been even lower IIRC, down at 72 octane for civilian use; basically...parafin!

If you were lucky, cars etc. could have their timing retarded enough to run on it; if not, if they were "high performance" types...you put them up on blocks in the garage for the duration. Motorcycles...99% single cylinder or v-twin in those days...could have their compression ratio lowered enough to run ok by a "compression plate" being fitted under the barrel at the mouth of the crancase....but that wouldn't work for multi-cylinder engines!

 

And also several ways of obtaining the anti-knock properties of high octane...many and various combinations of tetra-ethyl lead and aromatics. Some of which worked great...some of which caused as much damage as the original pre-detonation would have done!

The higher octane rating(s) allowed higher states of tune...as in higher compression ratios, wilder cam overlap etc. - but that's why wartime "performance" engines had shortish lifetimes of hundreds of hours as compared to the tens of thousands of hours of modern airliners. High performance means high wear...no matter what the octane rating.

 

Worked with an Italian fellow a few months back. His family went through ww2. They still own a lot of land, and his father was an Italian actor (TMI?). He says his grandma(?) said the Germans would go onto their land for water. They'd fill the truck gas tanks with water, then drop a "tablet" into the tank as well. Tablet would do something magical and trucks would drive away...I first thought-t-stoff-and s-stoff? Much to dangerous to use in an internal combustion engine...Tried to change his mind on what his gma thought she was seeing, to no avail...Apparently big oil is preventing us from finding out about this...lol...And the guy makes good money. ..Here I sit unemployed.