About the 912E
The crankcase and cylinders are similar to those of the VW-Porsche 914-2.0 but the engine mountings are unique to the 912E. All moving parts are identical to those of the original engine. A secondary air pump provides for exhaust emission control and is driven by a V-belt. The sheet metal ducting the cooling air around the engine was specially adapted for the 912E engine compartment. The fuel pump is mounted on the front cross member while the fuel filter is identical to that used in the 911s K-Jetronic injection system. Fuel is fed to the engine by a Bosch L-Jetronic system. The quantity of air aspirated by the engine is measured by a metering device, the signals of which are fed to an electronic control unit (ECU) located by the right-hand rear wheel arch. The exhaust silencer and the heat exchangers for the exhaust emission control comprising secondary air injection, thermoreactors and gas recirculation were specially developed for the car. The operation of the exhaust gas recirculation had to be checked every 30,000 miles. To ensure that this limit was not exceeded, the speedometer was fitted with a special counter triggering an EGR warning light when this mileage was reached. Click here for instructions on how to reset this light.
The VW-made engine has bore and stroke dimensions of 94 x 71 mm (3.7 x 2.8 inches), giving a total capacity of 1,971 cc. With a compression ration of 7.6:1, it has an output of 90 bhp at 4,900 rpm. Its highest torque of 14 mkg (102 lb/ft) is reached at 4,000 rmp.
It is not uncommon to find that the heads on your engine have been rebuilt. A common failure on the Type IV engine is a dropped valve seat, and it is the problem that usually required the tear-down. Apparently, the Type IV 2.0 heads were reworked by Porsche for better flow characteristics. However, in doing this they removed a lot of material from the case, rendering the wall between the exhaust chamber and the exhaust stud very thin. Unfortunately this can cause heat to transfer through the aluminium head wall to the steel exhaust stud, causing it to expand and crack the head. Spark plugs can also heat up and expand in the same way, cracking the heads and also dropping valve seats.
The heads may be salvageable, however. A good machine shop or Type IV specialist should be able to cut out the crack and reweld the head. Some may be too far gone though. Rebuilding Type IV heads is a specialized job, and not something you want to attempt yourself. It pays to use a major rebuilder like GEX. Jake Raby recommends Hoffman Automotive Machine, Inc. in Athens, GA.
There is an excellent article on the Lone Star 912 website - Tips on Type IV rebuilds, written by Vince Cotto.