Is there any good information on building the EJ 2.2 AND 2.5 engines for aircraft use. Also, looking for any information on Subaru engines in
general.
I'm in the same situation as you. Trying to find how to convert the wiring harness for the ECU.
I spoke with Don Parham who used to convert Subaru engines for aircraft use. He does recommend the 2.5 over the 2.2.
The problem with the 2.5 is redoing the wiring harness to work as an aircraft engine. Don said after 2005 the wiring harness was changed for the 2.5 Making it extremely hard to convert the harness. Don said he converted 2-2005 harnesses and said he will not do another one.
For the 2.5 you want a wiring harness 2005 or earlier. For the 2.2 there were 2 different harnesses. There were also different ECUs for a manual transmission and automatic transmission.
After speaking with Don I will probably stick with a crate long block 2.2 to replace my current 2.2 rather than having it rebuilt. I will have the cam grind done which will give me the same HP as a 2.5. Since I don't know how to do the wiring harness. I will stick with the carburetor and distributor.
I do not think a 2.5 can use a carburetor and distributor.
For those who know Don. He has been retired for over 10 years and no longer does Subaru conversions. He is dealing with several health issues but he is still hanging in there at 83 years young.