Oval Pocket vs round pocket Optimax pistons..

[150aintenuff]

OK so can an 02 Oval pocket motor be swapped to the later round pocket pistons found in the pro XS?? without adverse effects, OBVIOUSLY need whole set.. BUT will they work or is there cylinder head differences that make them a NO GO


trying to make an XS out of a 2002 Standard block.. obvously its getting what ever it needs.. and thats the only physical assembly differences i can see... is the pocket design


current 225std opti use same slug and XS uses round pocket so i cant think they are OVERLY different...

if it was MY build id do a what the hell and try it.. but its for a VIP within the company .. so its gotta be right..

[Todd D]

Either piston will work. I've taken a motor apart that had been running with both styles. Someone did a dockside rebuild and put whatever junk they had laying around inside it.... Standard opti are flat top and these came in both round and oval cups.

There's a little more difference than just the cup shape in the xs pistons. The xs ones are domed for a slightly higher compression. If you're going to used the xs racing domed pistons you should also use the correct heads. The main key to turning thay into an xs is the correct fuel and air pressure. The air injectors are hopefully blue as the black ones are known to fail at standard pressure. The blue ones will handle the higher air pressure but are not designed for it. That's the reason behind the gray ones.... which are very expensive. Don't forget you need to get the ecu flashed.

Long story short it cheaper to sell that motor and find a used xs and freshen it up.

[150aintenuff]

Either piston will work. I've taken a motor apart that had been running with both styles. Someone did a dockside rebuild and put whatever junk they had laying around inside it.... Standard opti are flat top and these came in both round and oval cups.

There's a little more difference than just the cup shape in the xs pistons. The xs ones are domed for a slightly higher compression. If you're going to used the xs racing domed pistons you should also use the correct heads. The main key to turning thay into an xs is the correct fuel and air pressure. The air injectors are hopefully blue as the black ones are known to fail at standard pressure. The blue ones will handle the higher air pressure but are not designed for it. That's the reason behind the gray ones.... which are very expensive. Don't forget you need to get the ecu flashed.

Long story short it cheaper to sell that motor and find a used xs and freshen it up.

i have the grey air injectors in my parts pile. Just need cleaned and i have 4 sets of blue air. It has the maroon fuel already the rail springs regularors etc i also have So all i really dont have is the ecm program wich i can flash and the slugs