Porsche 917/30 Engine Build Up
Yesterday was the tear down of a Porsche 917/10 engine, today is the buildup of a Porsche 917/30 engine. Both versions of the engines are quite similar, with the Porsche 917/30 notably having a larger displacement of 5.4-liter version vs. the standard 5.0-liter twin-turbocharged engine from the 917/10 (although some American-based race teams had 5.4-liter engines in their 917/10s).
There are so many photos you can take during the rebuild of a Porsche 917 or 917/30 engine, but we’ll share a few to illustrate some of the main stages.
Image 1: Rotating assembly that is put together inside of the magnesium case. The metal pins you see pointing up help hold the titanium connecting rods upright as the other half of the case is lowered down.
Image 2: The second half of the magnesium is being installed. Gustav Nieche is on the left with our engine builder assisting on the right. Lining up the case is critical to ensure not to mar the metal surfaces and not to scrape the connecting rods as they pass through the cylinder holes. The large round disc on the end of the engine is the tool use to correctly time the engine.
Image 3: The two engine case halves are installed. You can see the titanium connecting rods peeking through the cylinder holes. We paint the exterior of the engine case the same color as what magnesium looks like to ensure a long-lasting surface finish during a restoration. It also helps protect the magnesium surface in general.
Image 4: Cylinders and pistons installed. The 917/30 engine has a compression ratio of 6.5:1.
Image 5: Camshaft drive and camshaft housing exposed. The engine has two of these, one on each side. They connect to the center crankshaft gear and sit in the middle of the 6 pistons and cylinders on each side of the engine. This transfers power from the crank directly to the camshafts.
Image 6: Porsche 917/30 cylinder head. Dual overhead camshafts. One mega intake valve and a slightly smaller exhaust valve. These are cast from aluminum and there are 12 individual cylinder heads on each engine.
Image 7: The engine now has all of its cylinder heads installed along with the magnesium camshaft housings on top of them. The engine is so heavy (over 520 pounds) completely built that it needs support on both sides of the case. The two holes on the top right and the bottom right of the engine are where the oil scavenging pumps are installed.
Image 8: Exhaust headers installed. We bead blast them to produce a like-new finish. Note that the oil scavenge pumps are now installed which are capped off.
Image 9: Right side up, the engine has its 12 individual butterfly valves installed. You can see the fan drive internals without the fan. The black plastic lines are the mechanical fuel injection lines. They will be routed cleanly at a later stage. You can see both distributors installed on the left and the right, missing their caps.
Image 10: The completed Porsche 917/30 engine. This is the spare engine for the 1973 Can-Am Championship Porsche 917/30-003, driven by Mark Donohue. You can see the mechanical fuel injection pump installed on the top right with 12 fuel lines protruding from it. The top right camshaft drives the mechanical fuel injection pump. The brown cylinder in the middle of the engine is where the oil filter is installed. Fiberglass shrouds cover the engine to direct airflow down from the crankshaft-driven fan past the cylinders. The pipe on top of the engine (blue/yellow pieces with a braided metal hose) is the crossover hose between both intake plenums. On the bottom of the engine you can see the oil scavenge pumps installed and hooked up to reroute oil. Lots of spark plugs! 24 of them, in fact. You do not want to be the lucky soul that has to change a set with the engine in the car!