My father-in-law is rebuilding the engine on a 1973 2.0. The repair manual mentions that the pistons should be domed. However, the actual pistons have more of a dwell at the top. If the pistons and crank shaft were replaced at some point, we aren't sure what would be the best way to move forward. Should we use the same type of pistons that are in there or go back to what the factory originally used? If we revert back to the factory domed pistons, would we also need to replace the crank shaft?

Thanks,
Paul

Only 1.7 pistons are domed. 2.0 USA have slight dish NOT be confused with VW bus piston which has a deep depression. Flat top Euro 2.0 are more commonly used for replacement. 5 hp better according to spec book.

This is how 2.0 US spec pistons should look. As mentioned, they are dished.

I've dismantled engines of all sizes. Only once have I encountered domed pistons, and they were not stock. Between the 914S on your other thread, and domed pistons, you have a lot of misinformation. What repair manual said that?

Thank you!

He was using the Haynes Owner's Workshop Manual, Porsche 914, 4 cylinder 1969-1976. Page 11 says light alloy with steel inserts, domed crowns for fuel injection, flat crowns for carburetors. Mine is a 2.0 with fuel injection.

If you haven't bought pistons yet, and if you're not building this engine to a racing-rule-book, then get AAPistons 96mm pistons and cylinders. Drop in ready and will work the factory fuel injection.

Mark...does your recomendation include the 96mm flat top set for 309.00 ?
Or are you suggesting a specific set from AA?
Thanks.

Bump please...

Make sure to properly gap the piston rings

https://aapistons.com/collections/piston-li...-kit-914-type-4