| Author | Message | ||
     Schmitty |
I also posted this in the Knowledge Vault, so don't flame me too bad! I am going to change the oil pump drive gear to the bronze gear on my XB9R race bike. While I'm at it I'm going to do a top end inspection. The bike has 5500 miles on it. I was thinking about dropping in a set of Wiseco forged piston and Wiseco rings in the standard bore. Is there any benefit to this with the standard bore? I don't have the cash to go big bore, but I'm adding the Micron full system, and having the bike dyno tuned. What is the standard compression ration for an XB9? The Wiseco catalog says 10:1 with their pistons and rings installed. They also claim the usual reduced friction and stronger, etc.. There is also a .010" over option. Is this for worn cylinders? Would 5500 miles have worn the cylinders that bad? Any help or knowledge is appreciated. Schmitty | ||
| Badlionsfan |
.010 over is for worn cylinders. 5500 miles is barely broke in, should be fine. stock is 10.0 to 1, so no advantage there. not sure what pistons have to do with friction. if your pistons are touching the cylinder walls, you got issues. unless you're planing on nitrous or something, leave it alone. | ||
| Björne666 |
Take the money you planned to buy pistons for a get a head job done. Same compression pistons will not add ponies in the stable, but better flowing heads will. :-) | ||
| Jackbequick |
Pistons that are .010 over will normally require cylinder re-boring to get them to fit. At 5,500 miles you should be fine with a new set of rings. But measuring the cylinders and pistons after your get it torn down will really help a lot on deciding it all. Jack | ||
| Badlionsfan |
why on earth would he even need a ring change at 5500 miles? it's barely broken in?  | ||
| M1combat |
Wiseco has .010" over pistons? | ||
| Badlionsfan |
yup. http://www.wiseco.com/PDFs/Catalogs/2008/VT/Buell. pdf | ||
| Jackbequick |
I mentioned the ring change because it is a race bike. It is common on some race engines to do a hone and ring replacement whenever the engine is torn down. But the are a lot of factors to consider. Like the measured wear, if any, on cylinder and piston, the appearance of the cylinder (original cross hatch honing marks all gone, etc.), the amount of time it takes to get the rings in broken in/sealing well after reassembly, etc. Schmitty, Just out of curiosity, do you run that on synthetics? Or break it in on regular oil and switch to synthetics? Some engines break in better on dinosaur oil than they do with the reduced friction of synthetics. Jack |
