This engine is out of an exceptionally original, one-owner, numbers matching 1973 911S coupe, with less than 30,000 original miles. Due to corrosion caused from the car sitting for 35 years, we completely rebuilt both the engine and MFI fuel system. The car and engine have both been meticulously preserved and restored. Strict attention to detail has been maintained throughout the entire preservation process.
We first evaluated and disassembled the engine. This evaluation helps us to determine the extent of build needed, as well as enables us to address the owner’s build preferences. All components were cleaned, then fully evaluated, tested and measured. On this engine, the camshafts, rockers and connecting rods were all in need of reconditioning. All crankcase and crankshaft oil passage plugs were removed for proper cleaning of the oil ports. We then installed new plugs and micro-polished the crankshaft. The intermediate shaft was replaced, as well as the timing chains, ramps, and tensioners. New genuine Mahle pistons and cylinders and ARP head studs and connecting rod bolts were installed. The pistons were balanced, as well as the connecting rods end to end. The cylinder heads were resurfaced and new valve guides were installed. Then all valve seats were cut on our Mira precision valve seat cutting machine from Switzerland. New performance valves were installed and valve lengths were set. New valve springs were pressure tested and spring heights were set. Deck height and compression ratio were checked and adjusted. All bearing specifications were checked and recorded.
Upon assembly, we measured and recorded all fitment and clearance specifications. We also rebuilt the fuel distributor, fuel pump and original drive shafts. The original heatexchangers had some rust. From a preservation stand point, we wanted to repair them, but still keep them looking as original. We cut out the rust, made new pieces, welded them into place, matched the texture of the original metal and blended the color to match. All heat exchanger and muffler flanges were then resurfaced. We also cut open the engine wiring harness and cleaned or replaced all contacts and connectors.
After the build was completed, we properly broke in and set up the engine. Once we had 100 miles on the engine, we changed the oil and filter, took an oil sample, cut open the oil filter (to check for debris), re-torqued the cylinder heads, adjusted the valves and went over the final engine set up. The owner was given a maintenance interval protocol to follow for proper care of the engine during the remainder of the break-in period.
With the car and engine sorted, preserved and ready for the road, it’s now time to embark on its next journey. Perhaps another trip to Mexico? Of course, providing the owner is up for the challenge. We know the car is.
To see the full preservation restoration of this car, click here.
