Phillps oil for Jabs

[facthunter]

The older mechanical injection system is fine if tuned like GAMI injectors. Aero engines are not power changed much and run at 100% and 75% most of the time.. Direct drive is OK for larger slower revving engines. Larger displacement are still fuel efficient and can be light in weight with prop as flywheel. The engine should not be dependent on electrical supply to keep running. I'm not talking about large aircraft. The Wankel is ok too even when supercharged for sportier applications. Use planetary gearing from an auto trans. Nev

 

 

[jetjr]

Very true and perhaps why performance and fuel use improvements arent as dramatic as in Auto world as aero engines mostly sit at set RPM and can be tuned accurately to work there.

 

EFI does allow more secure use of Mogas or mixed fuels but this is a gamble in itself.

 

 

[facthunter]

The lack of quality assurance with Mogas makes it a constant liability. Nev

 

 

[Paul davenport]

Gentle men with the greatest respect to you and the experience you have in aviation could I ask that we keep the discussion to relevant modern ideas and actual confirmable, quantifiable and documented evidence ,reference to second or third hand ,"I know some who saw or experienced etc etc " does not do this discussion justice. I am asking question because I don't know the answers ,if you don't know either ,but have a verifiable reference please please refer me to your information source . In MY experience EFI systems in autos WHEN correctly serviced are reliable and trouble free ( and I must say some owners don't do any maintainence and the systems certainly are not maintained like aero systems are ) and when combined with electronic ignition and a knock sensor result in outcomes which simply cannot be replicated by ancient magnetos and carburettors . Im sure aviation fuel quality in some countries leaves a lot to be desired even if it is still available and as you said it is being phased out. The system I am envisioning will stand alone without an alternator functioning for at least 30 minute ( depending on battery size) while you decide what you are going to do or go . Systems like this eliminate the need for such stringent controls on fuel quality ( no I am not advocating using any old fuel but there maybe circumstances where you may have to use a lower octane fuel to top up to get home, GA pilots have done this before ) as ignition timing is adjusted to suit fuel quality while still keeping the maximum power available for the fuel used . A pilot simply cannot monitor the fuel and ignition system in the same way. I would agree that aero engines have been optimised for 3 basic operating conditiions start, full power and cruise that leaves a lot of areas in between which could be optimised (cruise for endurance ,loiter etc )In the cruise mode even this could be improved as injection and timing would be in a constant state of flux with the system always looking for the peak operating conditions adjusting for temperature ,air density cylinder head temp egt . The current series of auto engines run just such a system ( without CHT) AND a compression ratio of 13 to 1 plus and all on 91 Ron and mogas which lack quality assurance so what I am asking for on our modest compression ratio,s is not really going to be an issue