The pistons and cylinders on the car were clearly not stock. The pistons were not looking bad, but an MC racing type. The cylinders were rusted, scored, and in at least one case had a broken cooling fin. Time to replace.
Orders of business:
- Find something that will fit the Super 90 head, which has a 22-degree angle for the cylinder head, versus the 30-degree found on the more common engines.
- Big bore kit. The 86mm (1720cc) variety was a favorite of the late great Harry Pellow. And in the words of well-respected Mr. Jack Staggs, with regards to staying stock, “Do you want to spend more money for lower power and inferior product?”
- Cast iron, not aluminum, cylinders. Again the recommendations of Harry Pellow and Jack Staggs.
Even narrowing down the specs still leaves you with a lot of choices to make. I’m a bit overwhelmed by the possible permutations between cast, forged, aluminum, iron, biral, graphite coated, and hypereutectic. I had to go research biral and hypereutectic. And I still have trouble saying the second one. In any case, then you can throw brand into the mix. Spoiled for choice I guess.
Luckily my new friend Soren Andersen brings a ton of experience to the party. He has had good luck with AA Performance products, and this is consistent with the feedback I can find on the Porsche 356 Registry Forum.
He suggests their cast iron cylinders are well machined, to close tolerances. The hypereutectic piston is solid, stable and dependable. The technique has been around for many years, and is well proven. This led us to a “Best bang for the buck” candidate. I’m not sure if the joke was intentional, but I’ll say “yes”.
AA Performance Products 86mm Porsche 356A & B Big Bore Piston & Cylinder Kit The Cylinders are Cast Iron with Graphite Coated Hypereutectic pistons with the 22° Angle, valve pockets, and the 22mm Pin. This kit requires no machine work, when installing in factory Porsche case & heads
Soren and my father also were not fans of some of the other options, like JE, that have 0 piston wrist pin offset, which could make for a ‘clacky’ engine.
