Hello everyone.
I definitely believe it would be beneficial to SP1 car owners / Racer's to be allowed to use any aftermarket pistons as long as the size, weight, and compression are identical to stock OEM. Even the Porsche repair manual offered repair group and oversized position options for the 944 and 924S. The stock bore is 100mm. The next oversized piston is 100.5mm and next size is 101mm. I received Porsche Factory training while employed at Brumos Porsche between 1981-1990, and the instructors agreed that there is little to no NO gain by this very minut amount of displacement change, and in fact, no additional tuning was required. These engine are 30 years old. I have built over 300 Porsche engines within the past 38 years of Porsche repair, and within the last 10 years 90% of ANY 944 or 924S which needs and engine rebuild have cylinders out of spec and pistons that have scored skirts. I would definitely be in favor of any piston manufacturer as long as the oversized piston is of exact size, weight, and compression. I have already talked to JE Pistons and Wossner, and have design already in progress. Cost will be very reasonable, and will allow customers and engine builders the ability to build their engines correctly. This would guarantee that the current engine block in your car could be used for years to come.
Also despite what others may say, these 1988 10.2:1 engines are getting hard to find, they are 30 years old, and also requires shipping cost which can be up to $300 or more.
I would also take this a step further. Once the maximum of 101mm bore has been reached, racers should have a second option to sleeve their blocks. This allows the user to go back to 100mm pistons, but this process is much more expensive. Regaurdless, I will be making these pistons for my street car and SCCA customers. They will be available in 100, 100.5 and 101mm, and 10.2:1 or 10.6:1 compression ratios.
If anyone has any questions, please feel free to call me, or email me at
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Thanks,
Albert Broadfoot