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since i dont have a manual yet and i havent messed with plated cylinders much, does anyone know aproximatly what piston wall clearnce is for plated cylinder with cast piston ? i havent got a super accurate measurement with a bore gauge yet but with feeler gauge it appeared about .005", but after i looked closer it looked more like .004-.0045. im assuming with new piston and plating it will be around .0025-.0035 ? anybody know ? or is .0045 normal for a bigbore motor with plating and cast piston ?

doesn't it depend on the application? With my "mo betta" port job, I'm running .003 with my nikasil and vertex. cart guys that run 10,000 rpm would run more so I hear but I doubt the would run cast piston. I have heard like .007 or .008 with the wiseco.

You mean plated'..... like torque plated....

Or Plated.... like Nikisil coated?

plated like nikisil. with my steel bore and wiseco i have my clearnace around .004". i was just wondering if the clearance should be tighter with nikisil, or if it should be about the same. also, anybody have an idea about how thick new nikisil is ? i figured around .003 would be good clearance for nikisil but i figured i would ask anyways

I wouldn't think it should be tighter unless you went w/ a aluminum sleeve. I think you can run a .002 - .0015 w/ aluminum. nik w/ steel bores run hotter so I'm told. Wait that doesn't make sense. If they run hotter they would expand more right. The nik slows heat transfer on the steel bore. I had my piston dome and head TBCed to help keep things cool and helps power also fights detonation. Powerseal USA did mine w/ a T plate. I had to provide the plate. They charged me an extra $25 to install the studs and plate. The studs and or steel needs to be removed from the jug before they dip in the chemicals.

They said .008 nik thickness before the honing is done I think. I asked them to do the .008 bore w/ the plate. They were to excited about the whole torque plate deal so I really have no way of knowing if the bore was done with it. I didn't want the nik to be thin in a octagon pattern.

Anyone know how to check to see if the bridge was relieve to the right depth? Powerseal did relieve it. I don't have a bore guage. I'm considering investing, don't want to though.

i have aluminum sleeve. im unfamiliar with nikisil cylinders but heres what ive gathered. .002-.003 clearance is probly ideal with cast piston, (but i may run a wiseco, im trying to locate one right now but if not then ill use a oem cast). im assuming i would send the new piston with the cylinder, and they would set the nikisil to the desired thickness....so the final product has around .003 ? i dont have a exhaust bridge, so that wont be a factor

geez, I wouldn't even consider a cast piston with the aluminum sleeve. The wiseco expands at the same rate as the sleeve allowing the tight fit. I was going to do the same thing but elected to put the $$ into a STR crank job and fresh suspension.

I've been considering killing the bridge as well. I don't know if I can or not with the porting I have at the moment. I don't want to loose ring life. more power is not as important to me as longevity. She got plenty of juice for MX.