can always drop subaru an email, they are good about answering them..
I used http://www.subaru.co...actus/index.jsp to drop them a line, we'll see what happens. Here's the text:
I was wondering if I could get some information on my engine designation. The owner's manual for the 1993 impreza lists the engine as being an EJ18S; this manual seems to have gone out both in and out of california so it doesn't seem to be a california designation. I thought it might mean single-cam, but I guess not all the EJ single cams have an "S" on the end of the designation. Would it be possible for me to get more information on Subaru engine designation codes, and especially the information on the engine in my 1993 Impreza LS?