I was in the shop today getting some pistons ready to install on a banshee build im doing,thought i would share this with everyone.I see alot of cylinders and pistons come in scored up and these tips will help you avoid all the scoring and make your topend last alittle longer.
The pistons i am working with are wiseco forged pistons,these are notorious for having very little if any chamfers on them.what this will do is scrape valuable oil from the cylinder walls providing no barrier between the cylinder and piston.
In this picture the piston on the left is straight out of the box from the factory how most guys will install it,the piston on the right has been modified
These are the edges you want to chamfer
To do this i use rubber abrasives like pictured below,this is what i would recommend using.These come in all shapes sizes and grits,if you have a dremel tool or something similar you can use these
This should be looked at everytime you bolt your cylinder back on,a new topend or if your just doing rings this should be one thing you look at.
Ring end gap is important aswell,to check this install each ring into the top of the cylinder and use the crown side of the piston to push the ring into the bore,you want the ring square to the bore so you can get an accurate measurement using a feeler gauge,minimum end gap is about .013" excessive end gap will cause problems aswell as kill your power.
After your rings have the proper gap you want to go back and dress the end on the rings with an oil stone to break the sharp edges
Checking this stuff and taking these steps will make a world of difference in how long your topend will last
The pistons i am working with are wiseco forged pistons,these are notorious for having very little if any chamfers on them.what this will do is scrape valuable oil from the cylinder walls providing no barrier between the cylinder and piston.
In this picture the piston on the left is straight out of the box from the factory how most guys will install it,the piston on the right has been modified
These are the edges you want to chamfer
To do this i use rubber abrasives like pictured below,this is what i would recommend using.These come in all shapes sizes and grits,if you have a dremel tool or something similar you can use these
This should be looked at everytime you bolt your cylinder back on,a new topend or if your just doing rings this should be one thing you look at.
Ring end gap is important aswell,to check this install each ring into the top of the cylinder and use the crown side of the piston to push the ring into the bore,you want the ring square to the bore so you can get an accurate measurement using a feeler gauge,minimum end gap is about .013" excessive end gap will cause problems aswell as kill your power.
After your rings have the proper gap you want to go back and dress the end on the rings with an oil stone to break the sharp edges
Checking this stuff and taking these steps will make a world of difference in how long your topend will last
