Do I have Yamaha, or Wiseco Pistons

[Tom Cole]

I bought a 1200 engine from a friend as a project.  The pistons are in great shape, but since I broke ring seal, I want to replace the rings.  Can anyone here help me with a way to identify if I have Wiseco or Yamaha pistons?

For what it is worth, the engine was originally built by Hank Scott, and knowing a real good valve job when I see one, I can tell you that the man knows his stuff.

[elimn8u_43]

From what I have seen the Wiescos have Legends etched into the top of the piston. The dome is also of a different shape than the stock FJs.

Geoff

[Tom Cole]

He ran race gas in the car and the build-up from the leaded fuel makes it hard to see anything yet.  I'm going to bead blast them, and hopefully it will make some numbers and maybe "legends" appear.

[elimn8u_43]

Use some combustion chamber cleaner on a rag first. The bead blasting may remove the legends print.

Geoff

[legends13]

post a few decent pics from different angles, and I might be able to tell you.

[Tom Cole]

Here it is.  Still dirty.

[Tom Cole]

Ah Ha!  I started cleaning it in a carbon/varnish remover and it says "legends" on it.

Y'all see the "before" picture,  I'll post an "after" picture tomorrow.  It needs to soak.

[Tom Cole]

After cleaning.

[gramps05]

Nice job, what brand carbon stripper did you use?

[Tom Cole]

Gunk Carb and Parts Cleaner.  It is in a 1 gallon paint can that has a little metal basket in it.  I bought it for about $18 at Advance Auto Parts.  I also used a little B-12 Chemtool and a fine wire brush and a scotchbrite wheel on my dremmel tool.  It took a while.

[qweedqwag]

Looks like that piston has seen some detonation.

[Tom Cole]

I didn't run this engine, so I am interested in how you can tell that.  I do know that the timing chain broke and it got a few valves bent.

[gramps05]

Looks more like the intake valves hit the piston when the chain broke!

[Tom Cole]

Yep, it bent the valves.

[MegaMang]

Seems to be a lot of information was deduced by looking at these pictures from the more experienced readers.  How about if you guys help us out by letting us know how you knew... 

Qweedqwag...  you mentioned detonation.  What was the indication?

Gramps05...  you mentioned intake valves hit the piston.  What was the indication?

There's no doubt that over time a good number of us will have nasty things happen to our engines, and then we'll find out the hard way how to tell, but in the meantime I'd love to know what was the tip off.

Thanks in advance for your experience,
Mike