From this point, the motor can generally be stripped down in large chunks. I removed both cam tower assemblies, exposing the cylinder heads. The engine cooling tin that is located on each side of the cylinders must then be removed. Using a breaker bar and some elbow grease, I was able to loosen the cylinder-head stud nuts without incident and the cylinder heads simply slid right off the cylinders.
Unless you are just dying to know what the internals of your cylinder heads look like, there is no need to disassemble them. Most machine shops perform the disassembly as part of the service. If you are planning on reusing your pistons and cylinders, make sure you don't drop the cylinders while trying to separate them from the pistons. They are made from aluminum and are expensive to replace. The cylinders will usually separate from the pistons quite easily, but a few can be stubborn and may require a gentle tap with a rubber mallet.
Removing the pistons from the connecting rods requires a steady hand and safety glasses. A small flat-head screwdriver can be used to pry the circlip free that holds the wrist pin in place. The circlips have quite a bit of tension and if you don't grab onto them as they are being excavated they can-and will-fling to the other side of the room or worse, hit you square in the forehead. Once they are removed, the pistons can be separated from the connecting rods by using the handle end of a small screwdriver or a small punch against the wrist pin and tapping lightly with a rubber mallet. You don't have to completely remove the wrist pin, just tap it out far enough to release the piston from the rod. Remember to keep the pistons with their corresponding cylinders if planning on reusing them.
Almost there! I removed all ancillary pieces on the case exterior, including the ignition distributor, crank pulley, breather cover, oil thermostat and almost too numerous to count case fastening hardware. The case was then deemed ready to be split and after some coaxing with a rubber mallet the case separated and left me with a beautiful view of the crankshaft (with the rods still attached), oil pump and intermediate shaft assembly. The crankshaft will lift right out and the oil pump and intermediate shaft assembly only requires the removal of three nuts and then they come out as a unit. All of the internal parts will be disassembled to receive a thorough cleaning, be reconditioned and brought back to original tolerances, and then cleaned thoroughly again in preparation for reassembly.
Follow along with the build as the next installment will cover in greater depth the various options available to SC and Carrera owners during the course of a standard or high-performance rebuild. I will be relying heavily on the excellent products from industry leaders ARP, AASCO, Andial, Dansk, Extrude Hone, Mahle, Magnecore, Web-Cam and 911Chips along with the talents of Steve and Dwain to help build a powerful, dependable and emissions-friendly motor.
| Horsepower per Displacement Comparison |
| Porsche 911 Street Engines (USA Spec) |
| Year | Model | Displacement/Injection | Horsepower | HP/liter |
| 1967 | 911S | 2.0L, Weber carbs | 160 @ 6600 rpm | 80.4 |
| 1969 | 911S | 2.0L, mechanical | 170 @ 6500 rpm | 85.4 |
| 1970-71 | 911S | 2.2L, mechanical | 180 @ 6500 rpm | 82.0 |
| 1972-73 | 911S | 2.4L, mechanical | 190 @ 6500 rpm | 81.2 |
| 1974 | 911S | 2.7L, CIS | 175 @ 5800 rpm | 65.1 |
| 1978-83 | 911 SC | 3.0L, CIS | 180 @ 5500 rpm | 60.1 |
| 1987-89 | 911 Carrera | 3.2L, Motronic | 217 @ 5900 rpm | 68.6 |
| 1989-94 | 964 | 3.6L, Motronic | 250 @ 6100 rpm | 69.4 |
| 1995 | 993 | 3.6L, Motronic | 272 @ 6100 rpm | 75.6 |
| 1996-97 | 993 | 3.6L, Motronic w/Variocam | 285 @ 6100 rpm | 79.2 |
| The stock U.S. spec 3.2L's output of 68.6 hp/liter leaves plenty of room for improvement when compared to some of Porsche's best street engines. |
| We're hoping to reach the 80 hp/liter mark with the planned modifications while still using 91-octane pump gas and remaining California-emissions compliant. |
| Source: "Porsche 911 Performance Handbook (2nd edition)" by Bruce Anderson |

The CIS/Motronic- type 95mm...

The CIS/Motronic- type 95mm pistons cannot be used with radical camshaft profiles due to inadequate valve-to-piston clearance caused by their wedge-dome top.

Like the rocker arms and shafts,...

Like the rocker arms and shafts, the pistons should remain with their corresponding cylinders if being reused. These 95mm units will be discarded in favor of 100mm units to make 3.5 liters.

Stock 3.2L cylinder heads....

Stock 3.2L cylinder heads. Note the placement of the spark plug in the combustion chamber due to the large 49mm intake and 41.5mm exhaust valves used on the SC and Carrera.

A sight for sore eyes! The...

A sight for sore eyes! The case has been split and the 74.4mm crank, oil pump and intermediate shaft assembly beckons. All will be thoroughly cleaned, tolerances checked and reconditioned, and thoroughly cleaned again prior to reassembly. "Cleanliness is next to Godliness" holds true for any 911 engine build, whether stock or race.