The pistons in questions are Turbo pistons. A good rule of thumb is make the valve pockets only as large as they need to be.
These valve pockets will handle most any turbo cam.

BTW: Here in the US, Perfect Bore cylinders cost more than this complete P&C set.
Cheers

What year motor are those cylinders going on? Would these cylinders also have these compression rings on them for say an '89 which has no gaskets?

The parts that I posted pictures of are going in my '87 930...as to the other pictures that might have been posted - no idea.

Granted this is my first experience with Henry's cylinders (and the JE pistons for that matter), but you really can't beat the price! Hell even the used (replated Nikasil) cylinders from EBS are more! These things are brand new. Henry offers a pretty stout warranty/guarantee on the engines that he builds, and I'm confident he's using these cylinders in his own engines! So what the hell...I rolled the dice, we'll see!

I really am curious about that "gasket" on your cylinders. I bought a set of pistons and had the cylinders replated through EBS. I questioned them about the need for any additional machining or need for a gasket where it mates with the head and they said that there was no need. I have been supercharging my motor and will do so again when I have completed the assembly.

Well you have to remember, on my engine - a stock 911 Turbo - there is no gasket between the head and cylinder. A common option was to run the Nirosist sealing rings. However, using superior ARP, Supertec, Performance Developments, Raceware, etc head studs also helps keep these things from lifting as bad as that Dilavar shiz!

The 3.2/3.3 cylinders used a .0015-.003" taper across the sealing surface rather than a sealing ring, if you were wondering. With a good set of studs and stockish boost, that's plenty sufficient to seal the cylinder off. As the bore increases, the "real estate" for sealing the cylinder and head off shrinks and typically, those going that route also up the boost, and the two together require additional procedures for sealing the cylinder and head off. Performance Development and CMW Motorsports (there are others too) use a double interlocking sealing ring that indexes both on the cylinder and head and I have used both with excellent results.

Henry, so for the set of 98mm that you are listing on ebay, does it mean that I can request a different set up (compression ratio) for turbo application? Will that set fit?

thanks.

Thanks Charles. My parts are at Performance Development right now. Neil Harvey was concerned because he wasn't sure if he needed to machine a groove into the actual cylinder head to accept Henry's sealing ring. I told him that no additional machining is required.