mikestrikes wrote on 05/14/09 at 19:17:30: Quote:Gee whiz! Then what did I just put in my S-40?
Phelonius
Well they list it under the dirtbikes, and the person who e-mailed me back said no they dont carry that.
May be wrong but I sure cant find it. Got any pics ?
I'd like to get my hands on a Forged piston with a slightly raised top and valve cutouts....
We can get some custom pistons if we can get 4 or more people wanting them from ROSS Pistons, they only make custom slugs in 4's...
Get them in the same dia as that of Chevy 305 V8's and we can use the Gapless Ring sets !!! When you look under dirt bikes in the Wisco site, You find the pistons fo the 96 and earlier DR 650s. Then if you look closely, you will see that they are also for the LS 650.
I called on the phone and it was verified. I also asked about how thin the cylinder liner could be bored. They said even down in the skirt area,(the part that extends down in to the block), do not have less than .080" thickness.
My skirt area measured 101mm on the outside. If I bored for a 96mm piston that would leave 5mm difference. Divide that by two and get 2and 1/2 mm thickness. That is as thin as I wanted to go so I bought the 96mm piston and merely wished for the 97.
Be advised. the piston and wrist pin together in the stock engine weighs 33 grams more than the Wisco piston and wrist pin.
You can either put up with a slight imbalance and the vibration it induces, or add weight to the wrist pin to match the original weight.
I did the latter.
BTW the Wisco piston has a raised crown that in addityion will give an increase in compression. Use the better grade of gas with this piston.
Phelonius