Page 22 - KCRPCA MayJune 2021

NUTS & BOLTS
M96 WATERCOOLED
SOME SAY, THE “M” IS FOR MYSTERIOUS
TECHNICAL EDITOR KARL WILEN
Porsche’s watercooled en- gines since 1997 (US) have continued to be a mystery to many people on their design and function due to the vast dif- ferences that exist between them and a more commonly designed engine. We all know about the intermediate shaft bearing issue, but not a lot of people understand what that bearing is, where it resides in the engine, or what it does. I thought a little engine re- fresh project would help illustrate the internals of these engines as most people are visual learners. I’ll break it down into a couple articles, depending on how much I ramble on. This article is not
a fully documented engine re- build. There are a lot of steps that I don’t have the time or space to show, but rather want to just illus- trate the general assembly of the engine. In fact, the factory manu- als are incorrect in the proper
assembly of the engine in many instances, so keep that in mind.
We are starting with a 2.5L 1999 engine out of a Boxster. Though the differences are slight from 1997 through 2008 between the M96/M97 engines, the big- gest differences are the variocam design and the intermediate shaft bearing design. In the case of this engine, I have done a full teardown on a good running spare engine in preparation of refresh- ing it as a backup engine for a SPEC Boxster. There is a big difference between rebuilding an engine that has had a component fail, and a more simple refresh
as in this case. If something has failed, the parts components you will be having to replace will be much higher and more expensive.
So the idea is to go from a pile of parts, to a long block like this:
(This is a 3.2L long block that
16
22
Der Sportwagen
YEARS