H6 ZE30 (& EZ30R) Flat Six Subaru 3.0 engines:
The EZ30’s have chain driven quad cams. They are identified by having a cast aluminium induction manifold, and alloy cam chain covers. The EZ30R is the second generation EZ30 engine. They look pretty similar to their predecessor, but are far from it. Something like 80% of the parts are new, and they are much higher tech. They feature both variable valve timing and duration, a variable induction system, and a ‘drive by wire’ throttle. They are identified by having a plastic induction manifold. Both of these weigh only a bit more than the EJ25, and are only slightly longer. At the time the EZ30R was launched, they were the lightest six cylinder 3.0 litre engine available.