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nomorecatering
10th Jan 2010, 05:19
I've been reading about the new fuel 94UL and some of the problems it will have in the highly boosted turbo engines, which need a higher octane rating.

It seems that direct injection is the answer. Apparently direct injection, where the fuel is injected straight into the cylinder at enormous pressure (around 27,000 psi), an interesting thing happens. When the fuel is injected, it has a marked cooling effect on the charge air which has allowed the engineers to bump up the compression ration by half a point. eg 12:1 to 12.5 :1 Porsche is the latest convert to this technology.

Perhaps this cooling would allow the compressio ration in an aero engine to be bumped up a tad to restore the power.

So, what about combining 94UL with FADEC technology and direct injection. Seems to my simple mind a perfect solution untill the diesel technology is perfected.....which it will, given time.

Thoughts anyone?

411A
10th Jan 2010, 07:51
Cylinders would need to be redesigned to handle 12.5/1 ratios the highest generaly used with aero piston engines today is 9/1.
An alternative to 100LL is being developed and tested now, with good results....so far, and, this alternative will require minimal engine mods, in many cases, except a changed mixture (easily accomplished).
FADAC has been certified on some TCM Continental engines as well.
In addition, direct fuel injection has been used for at least fifty years on many spark ignition aero engines.
Nothing new, either