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Re: Cummins engine swap questions

PostPosted: Sun Feb 10, 2019 5:21 pm
by nikkinutshop
It is here and has been for nearly a decade. I can not say that CI is used instead of SI because I have not had enough interest to check it out. I did see one article on something DI gasoline. The suggestion was this featured gasoline direct injection engine used a spark at cold start and then went CI when the engine reached running temperature. Maybe it is time for me to have another "good-look". At 73, I have less interest in the newer stuff. Today, I want to get out to the garage and not fall down. We are being snowed on, heavily, and it is sticking.

Re: Cummins engine swap questions

PostPosted: Sun Feb 10, 2019 5:42 pm
by cornbinder89
From what I have been able to find and read, it is still spark ign. The Direct injection is into the combustion chamber but before full compression has taken place, so the full charge is in the combustion chamber then lit by a spark. Compression Ign would require injecting at higher pressures and at the correct time like with a diesel. In order for Compression Ign gasoline to be practical the pressure has to be high enough for the fuel to ignite as it is being injected, but right now they haven't got a pump/injector that can handle the pressure without seizing as gasoline has no lube properties to it.
As long as the full charge is in the combustion area before ignition, detonation is a possibility, so compression pressure is limited.
I know they are working on it, but as far as I know no one has a fully functioning compression ignition gasoline out there yet.