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.
As I complete the engine revitalization follow the link at the bottom of this article to see the actions that I take to prepare this engine, transaxle and entire Porsche for another decade of trouble-free service as my daily driver.
This is my personal engine, these are my accounts.
-Assembled late August 2002
-Engine was based
-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
-Engine saw two valve adjustments since new, the last recorded February
-Engine went 23,000 miles on a single oil service
-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
-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
-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
-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.
Here #985 sits poised ready for revitalization in my personal workshop here at the RAT facility.
NASTY! 160K miles of road grime
Another view shows some oil leakage from the engine, but keep in mind this is synthetic oil and more prone to leakage in a vintage engine.
Also, the oil that was in this engine at the time of teardown had been in the engine since 2008 when
Here is a shot of the engine after having the wiring nightmare associated with 3 different EFI systems applied removed. That alternator belt has 60K miles on it!
Engine and transaxle removed, ready for transport to the RAT teardown building for
Delivery to teardown via forklift, we’ll remove the 923 transaxles next
The engine and tranny are so dirty they look like one unit!
Engine mounts were shot from the chassis dyno sessions and hard driving!
These cylinders were in great shape only needing a plateau finish hone before being reused!
Never a head temp over 400F in 160K miles!
Cylinder head removed from bank1-2. No cracks noted, just nastiness
More shots of the 3-4 bank parts
Heavily carboned Keith Black 96mm piston. Rings were .004 worn compared to their installed sizes.
Look at that nasty oil!!! How could an engine with oil that nasty look almost new inside??
Is that straight crude oil??? LOL!
Experimental Keith Black pistons
Case split, note the sludge in the sump but how shiny and beautiful the journals are.
Center main bearing (#2) looks near new! I expected this bearing to be worn into the copper!
#1 main bearing bore. Note fretting, indicative that the engine will require an
#2 center main bearing from the 3-4 bank case
#3 main bearing OD view. Note the fretting
#1 Main bearing, fretting heavily evident. This is the only wear the engine has!
Camshaft bearings. Perfect, but will be replaced with RAT HD Extreme bearings
Camshaft lobes. This aggressive camshaft should be much more worn! I challenge anyone to use other components than that of RAT and experience beautiful lobes like these in even 1/2 this amount of service life!
Center main crankshaft journal… No wear, it measures perfectly!
BEAUTIFUL! Camshaft end play still where it was set at assembly, .003
Even without double thrust camshaft bearings this engine still shows no bearing wear!
Another shot of the opposing center main.
More fretting…#1 main saddle
The big nasty picture!!!|
Beautiful! Note proper alignment of oiling passage in center main bearing
#1 main journal on
#1 Main bearing… Beautiful!
Rod bearing that looks like new!!! These could be reused!