what oil for brand new piston?

[frosti108]

if i was about to break in a new piston and rings only, am i supposed to use regular oil instead of synthetic during break in? or can i keep using my synthetic?

it was my understanding that im supposed to use regular oil for break in, then afterwards i can switch back to synthetic... am i right?

because i just started thinking about a 12:1 piston instead of my 11:1... :devil:

[cals400ex]

yes, use regular and not synthetic on break in. i don't think the brand makes a huge difference.

[sleepin400]

yeah, don't use synthetic. the cross hatch pattern on the bore acts to seat the piston rings and with too little friction it will not seat fast enough.

You can run sythetic later though. Run a couple hrs through it. You'll be fine.