Which Subaru Service Manual do I Buy?
From our research lately, we've discovered some information about these motors that we would like to share. There has been quite a lot of questions about what Service Manual to use on these engines. H6, E6 (Eggenfellner's tag name), EZ30D and EZ30D-R are synonymous for the same general motor: A 3.0 Liter, horizontally opposed, Dual Overhead Cam, 6 cylinder Subaru engine.
There is some very good background information about the Subaru engines found at the following wikipedia: http://en.wikipedia.org/wiki/List_of_Subaru_engines
This wiki has some minor errors, that we will try to clear up. If you scroll to the section of this wiki that lists the 6 cylinder motors, you will note that there are two listings for EZ30D. Both of these are DOHC, but the first one listed has slightly less horsepower, and is listed *incorrectly* as found in 2000-2002 models. It's actually found in models through 2004. This 6 cylinder engine is very easy to identify because it has only a single exhaust port per head. This engine is what is referred to as Eggenfellner's early H6.
The second EZ30D was introduced with changes to the valve assemblies with features such as Variable Valve Lift (VVL) and Active Valve Control System (AVCS). This engine has a higher horsepower rating than the early EZ30D. This variation of the EZ30D sometimes is found by the names of: EZ30R, EZ30D-R and models of vehicles with this engine were listed with 3.0R. The wiki also mistakenly lists the engine as found in 2003 and 2006 and later models. Our research shows that it's actually found in 2005 and later models. This engine is also very easy to identify because it has a single exhaust port per cylinder. This engine is what is referred to as Eggenfellner's later H6 - about the time Jan started calling them the E6.
So, when hunting down Service Manuals for these motors, the early EZ30D can be found in the 2000-2004 Outback with the 3.0 Liter 6 cylinder engine. The later EZ30D Service Manual can be found in the 2005 and later Outback with the 3.0R 6 cylinder engine. As far as we can tell, as long as you get a Service manual in any of these two *broad* year ranges, it should be perfect for the motor you have. The key is to determine if you have a single exhaust pipe on each head, or 3 pipes into one on each head.
Hope this helps,
Michael O'Brien, RV-7A, E6/200, EZ30D-R, 65 hours.