Are these OEM pistons not as good as Wiseco?

[rd400canuck]

Hi again guys,

I just got the cylinders and pistons I ordered from the fella in Texas.. Everything looks great but I was expecting to see lines in the walls... these are completely smooth. I thought the lines where there to hold oil against the wall to deter wear. If that's the case I might order some wisecos. Plus I think the Wisecos have bigger windows that is preferable? Or should I just run them and not think too much lol

[m in sc]

they each have their place. In hot applications wisecos are good, however they require wider clearances. but stronger. No, there doesn't need to be grooves to hold the oil. Me? i prefer oem style. I run them in my lc hybrid, and that thing makes very good power.

Side seizures come from overheating usually, and the piston expanding at taking up the clearances.


the question is: what do you plan on doing with the motor> street motor with maybe chambers and such, but nothing too radical? oem is good.

[rd400canuck]

ok good to hear...

The bike will remain 100% for the most enjoyable and relaxing evening and weekend rides.

Also, the bores are freshly bored and honed to 1mm over. I assume he had them bored to these types of pistons if they dont expand like wisecos. He's a long time RD gear head, 40 years at least, so I have to assume he knew what to ask for. Id better email him and ask.

Out of curiosity what are the clearance difference between oem and wiseco ?

[SUPERTUNE]

Cast pistons on todays fuel's like about .002 in.
I run Wisecos a little over .003 for street and .0035 for track bikes.
Chuck