Cylinder Bore Question!!! need help

[fosterblaster]

i have a blaster cylinder that i bought and ik how much it is bored out i just dont know what oversize piston to put into it. it measures 66.7mm what oversize size piston do i need? and which piston is the best to use?

 

[brandoz28]

you need to know more that 66.7........


the piston to wall clearance is around .003, you need to have it properly measured by a machine shop so that they can tell you what piston to put in it

 

[Awk08]

sounds to me that a 66.50 piston will have 2 thousandths clearence in that jug, but i'd still let a professional tell me if that bore is good, and what size piston to use,
a wiseco piston of course !!!!!

 

[blasterboy91]

how much is it bored???

 

[fosterblaster]

im not sure how much it is bored. i measured it and its around 66.7 and stock os 66. i was told to run a 66.5 piston so i have .002-.003 piston to wall clearence and that the rinds will make up for it

 

[R&S Polishing]

most shops in my area charge $65.00 for a bore and champfer

 

[blasterfreek30]

most shops in my area charge $65.00 for a bore and champfer

thats about the same around here too

 

[blasterboy91]

$50 for me...includes everything...

 

[Surfrjag]

i just got one done locally for 30 but took him almost a week to get it done.

 

[royalt67]

Going just on your measurement, .7mm is about .028". That means you are going to have to bore it to at least .030" or third oversize. This depends on the condition of the cylinder tho. My machine guy likes to take out at least .010 each time just to true up any taper and whatnot.

I would plan on a .040" (67mm) piston, but bottom line is most machinists want the piston in hand before boring, just to cut down on the "idiot factor". Take it to where you are going to have it bored, have them measure it and tell you what size to get. Then when you have the piston, give it to em and let them bore it.