Question:
Hey Guys, how goes it? Just wanted your opinion on my top end.
Long story short my suspension guy put my motor together and inverted
the base gasket letting oil out and a bit of water in.
I caught it after 10-15 hours and from what I can tell there is no real
damage. I will disassemble the top end and clean everything up.
But since I have it apart I wanted you thoughts on getting a piston
(cast or forged) or if I should run this for a little longer?
It is a Wiseco that looks...ok? How does the cylinder look to you? You
can see wear but can't actually feel anything.
Get the cylinder plated? Keep using it? (LA Sleeve by the way)
Hope all is well and let me know your thoughts?
Regards
Answer
Hello Greg.
This is based on the pics that you sent me.
If I was going to be responsible for a warranty, and maintain a good reputation, I would say to have it plated, or bore to the next size up, and install a new piston, rings, ect.
But, if it was my own bike and I wasn't worried about my reputation or a warranty, what would I do?
The one thing that would help me decide would be to run a stone hone (You can get one at any auto shop) through the cylinder for about 15-20 seconds, clean it, and then look for defects.
Then I would accurately measure the bore and see where it is.
Cast or Forged?
I like forged but I have used both for many years successfully.
Before you run out and buy a bunch of parts let's see how the bore of the cylinder cleans up.
Also, I would remove the rings and get some fine steel wool and clean all the carbon off so I could thoroughly inspect it and accurately measure it.
If I found no major defects in the bore or the piston, I would put a new set of rings in it and run it.
Let me know what you find.
Thanks!
Response from customer:
Guys, I have put a new OEM top-end in it.
I have run that twice, about 5 minutes each time, to check for leaks.
My worry is the ring end gap is tight, about 10 thou. I did not measure piston to wall clearance.
It is easy enough to pull it apart, and send it to my local machine shop for a hone and accurate measurements.
Then I think I will go from there. Bought cast because it will expand less...reduce chance of cold seizure, which I have do once with the Wiseco that you saw.
If it measure good break-in and ride.
Good plan?
Our final response
Greg.
.010 is a bit on the tight side.
However, if you are very careful on break in, and your cooling system is in good order you should be ok.
I'd run it
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The biggest problem with answering these kinds of questions is not having the parts in your hand to inspect.
A picture is good but does not show you every detail.
Also in this case, the customer did not wait for an answer and went ahead with the repair.
This may or may not work out in the end.
I guess time will tell.
.010 ring end gap is a bit concerning as I'd rather see .0135" as a minimum.
If he's careful and everything else is correct he might be ok.
Incidentally Wiseco's rings come in at about .018-.024" out of the box.
