legacycentral bbs

So after building a motor for the Legacy, I noticed some differences between oil pump springs. The motor I started with was a 2003 Forester 2.5L block, crank, and oil pump with low, low miles. I was going to shim under the spring in the Forester oil pump and decided to place it next to a WRX oil pump spring as well. The difference in height and coil thickness was definitely different. The WRX spring, which is the same as the STi spring (minus a washer), was taller with thicker coils.

I had always thought that the pumps were nearly the same except for the amount of shim they decide to use. In this case the spring was different as well. I used the WRX spring along with three shims.

No biggie just thought this might be useful to someone.

Considering the two pumps run different relief pressures, I don't see this being that big of a discovery.

SemperGuard wrote:Considering the two pumps run different relief pressures, I don't see this being that big of a discovery.

Obviously not a huge discovery, but I thought the differenece was with the shimming which is done from the factory. Just an observation man. I've built 5 Subaru motors in the past three years now and never noticed this. Of course, I always started out with turbo pumps to begin with