High Mileage Teardown
Living in Hell
160,000 Miles of Service Revealed
A photo documented autopsy by Jake Raby
The story and associated information you are about to read began September 3, 2002, when I first installed this engine into my 912E. The next 8 years of the engine’s life would be filled with neglect, abuse and the chores associated with being a four-season daily driver in the mountains of North Georgia over a span of 160,000 trouble-free miles.
I will begin by posting facts related to the life of this engine, when it was serviced, how it was treated and maintained. I will then share my original intent with this engine, how it was designed, how it was assembled and the parts that I used to create it. This story will illustrate the robust design of the Type 4 engine and what can be expected when Aircooled Technology takes the engine to the next level of performance, reliability, and longevity. I have kept extensive records relating to this engine for the very purposes of this autopsy that unfolds below.
-Assembled late August 2002
-Engine was based from the original 100K mile donor from 912600985
-2056cc “912E Special” combination
-Average fuel economy of 32 MPG. Peak MPG 41 MPG in 2003
-Oil consumption average 1.8qt in 5K miles
-RAT Engine Dyno power (new) :129HP, 123lb/ft torque (see graphs at bottom)
-Engine used synthetic lubricant ONLY after 500 mile break in
-Engine saw two valve adjustments since new, the last recorded February 3 2003
-Engine went 23,000 miles on a single oil service
-Engine only saw 14 oil services in 160,000 miles (sometimes the filter wasn’t changed for 3 services in a row!)
-This engine was pulled for autopsy only, it did NOT fail!
-All work was done as an educational exploration and to prepare the 912E for 10 more years of service as my daily driver. (it was pulled to service the 260K mile transaxle!)
-This engine had ZERO occurrences where it wasn’t 100% reliable
-No repairs were made to the engine during its time in service
-Engine used carburetors for the first 59,000 miles
-Was converted to programmble EFI in 2004 and was used to test three different ECUs for the RAT engine program
-Engine was built with daily driver performance in mind
-Engine/ car saw 5 PCA DE events at Road Atlanta and Roebling Road in 2003-2004 (over 1200 track miles)
-The final dyno chart for the engine plots 102RWHP on our dyno jet chassis dyno(see graph at bottom of page). This means the engine was making the same power as new with 160,000 hard miles on the odometer and little service performed!
-Engine comprised 100% of RAT and OE components
-All internal components were cryogenically enhanced with the RAT profile
-Engine was not removed for all 8 years of service, not even for clutch service
-After 8 years and 160,000 miles of service the engine still produced 9HP more than the original 2.0 912E factory engine rating of 76HP!
-Until the day the vehicle came off the road for the 2010 revitalization the engine was running perfect, barely leaked oil and had no notable oil consumption.
Also, the oil that was in this engine at the time of teardown had been in the engine since 2008 when i decided not to service the engine any longer!
These cylinders were in great shape only needing a plateau finish hone before being reused!
Heavily carboned Keith Black 96mm piston. Rings were .004 worn compared to their installed sizes.
Is that straight crude oil??? LOL!
#2 center main bearing from the 3-4 bank case half.. PERFECT! Zero wear!
#1 Main bearing, fretting heavily evident. This is the only wear the engine has!
Center main crankshaft journal… No wear, it measures perfectly!
Finally some wear!! This center main suffered from extreme case shuffling, probably due to higher RPM and the necessity for align bore.
The big nasty picture!!!|
#1 Main bearing… Beautiful!
More later.. Graphs and links to the new engine to come!