how do you measure piston size in a cylinder?

[scotj77]

Is that going to be a sustainable ride phrag? or will it be hard to keep cool. probably a dumb question with your records but i was curious

 

[phragle]

My goal is sustainable and rideable, albiet it on 110 octane.

 

[Surfrjag]

DIAL CYLINDER BORE GAGE TOOL KIT CALIPER MICROMETER: eBay Motors (item 280482144590 end time Nov-16-10 09:06:48 PST)
is this what you would want to use to properly set up a cylinder?
and would it be safe to assume that if one ordered a piston, in my case, as 72.5 mm that its exactly that? or would one want to measure the piston too?

 

[brandoz28]

with tolerances needing to be that close, you have to measure.


this is real blueprinted race motors have pistons/rings matched to each individual bore as the machine shop goes through it

 

[jrn2786]

Harbor Freight has i caliper for $2.99 thats how i measured mine

 

[caseywoods5]

not sure of horsepower... going to shoot for 45~50 this comming spring.

As for blasters, I raced and wrenched on my first one in spring of 1988, early in the first year of production.

can't wait to see your build then I:I and that is awesome! i bet you were one of the first people to race a blasty?

 

[Midwayusa]

DIAL CYLINDER BORE GAGE TOOL KIT CALIPER MICROMETER: eBay Motors (item 280482144590 end time Nov-16-10 09:06:48 PST)
is this what you would want to use to properly set up a cylinder?
and would it be safe to assume that if one ordered a piston, in my case, as 72.5 mm that its exactly that? or would one want to measure the piston too?

That is what you would use to measure the bore. Need a micrometer to measure the piston. We use a Sunnen dial bore gage but they are very expensive. Anyway we measure the piston, add the clearance then set up the dial bore gage with the same micrometer. Calipers will get you in the ballpark but not accurate enough for finished sizing.