I started a project log on my EFI project: Microsquirt EFI on a Jabiru 3300 I will explain more about the project in this discussion thread.
The engine is on a Rans S7. The early Jabiru engines have a number of problems and my engine is an early 1st Generation engine so it doesn't have most of the improvements that have been made over the years. The primary problem is overheating and I have chronicled my work to keep my engine cool on this forum. I have more work to do in that area but I succeeded in bringing my operating temperatures within limits while increasing the power levels.
With engine temperatures under control, I am now concentrating on reducing the temperature spread between cylinders. Reducing the temperature spread will allow me to operate at higher power levels since I won't have to throttle back to keep one cylinder cooler. The Jabiru 3300 is known for poor mixture distribution which leads to overly rich cold running cylinders and lean hot running cylinders. Thus my motivation for installing EFI is to even the mixture distribution and hopefully even the temperatures between cylinders so I can maintain full power during climb.
The obvious choice for EFI here on this forum is SDSEFI since it is a well developed system designed for aircraft and Ross, the developer, is here on the forum. Instead, I decided to use a Microsquirt ECU on my project. One reason is because I felt I will learn more about engine management systems by taking a more do it yourself approach. Ross's system is pretty much a canned system with minimal tuning required. Where's the fun in that? Most of the work to install the EFI hardware is the same whether you use SDS or some other ECU. Ross does have bolt on parts for aircraft engines so his system is easier to install if you use his parts. I like to tinker and make stuff so that isn't a factor in my choice. The biggest difference between the systems for me is that the Microsquirt will require more time to tune so I will have to fly more to get it sorted out.
The case can be made that SDEFI is a more reliable system since it is a simplified system designed for aircraft. I am keeping the existing fuel system and gravity fed Aeroinjector as backup so I am not worried about reliability at this point. The Aeroinjector will be the throttle body for the EFI and keeping the existing system will make tuning easier. I will be able to take off with the existing system and then switch to the EFI at safe altitudes for tuning purposes. And, after all is said and done, if the Microsquirt fails I will replace it with SDS.
We are going to have winter weather for the next week or so I should be able to make more progress.
The engine is on a Rans S7. The early Jabiru engines have a number of problems and my engine is an early 1st Generation engine so it doesn't have most of the improvements that have been made over the years. The primary problem is overheating and I have chronicled my work to keep my engine cool on this forum. I have more work to do in that area but I succeeded in bringing my operating temperatures within limits while increasing the power levels.
With engine temperatures under control, I am now concentrating on reducing the temperature spread between cylinders. Reducing the temperature spread will allow me to operate at higher power levels since I won't have to throttle back to keep one cylinder cooler. The Jabiru 3300 is known for poor mixture distribution which leads to overly rich cold running cylinders and lean hot running cylinders. Thus my motivation for installing EFI is to even the mixture distribution and hopefully even the temperatures between cylinders so I can maintain full power during climb.
The obvious choice for EFI here on this forum is SDSEFI since it is a well developed system designed for aircraft and Ross, the developer, is here on the forum. Instead, I decided to use a Microsquirt ECU on my project. One reason is because I felt I will learn more about engine management systems by taking a more do it yourself approach. Ross's system is pretty much a canned system with minimal tuning required. Where's the fun in that? Most of the work to install the EFI hardware is the same whether you use SDS or some other ECU. Ross does have bolt on parts for aircraft engines so his system is easier to install if you use his parts. I like to tinker and make stuff so that isn't a factor in my choice. The biggest difference between the systems for me is that the Microsquirt will require more time to tune so I will have to fly more to get it sorted out.
The case can be made that SDEFI is a more reliable system since it is a simplified system designed for aircraft. I am keeping the existing fuel system and gravity fed Aeroinjector as backup so I am not worried about reliability at this point. The Aeroinjector will be the throttle body for the EFI and keeping the existing system will make tuning easier. I will be able to take off with the existing system and then switch to the EFI at safe altitudes for tuning purposes. And, after all is said and done, if the Microsquirt fails I will replace it with SDS.
We are going to have winter weather for the next week or so I should be able to make more progress.
