Piston ring and Bore size help

[kaetosgsx]

Hello, I am replacing the rings and bearings in my 7 bolt block (95 eclipse gst) and today I measured the top of my cylinder 2 and 3 and there is a small difference from the top of the bore to about half inch below...

Question...

1. Is this normal?
2. I measured 85.10, 84.67 and 85.00 in the same piston, I believe that I am stock bore.
3. My piston 1 which is raised all the way to the block face has minimal play... this lead me to measure to see if I need to machine the block... Is this normal?

Appreciate the help. DSM noob here.

 

[donniekak]

How are you measuring?

To do it right you need a setting fixture and bore gauge.

 

[kaetosgsx]

How are you measuring?

To do it right you need a setting fixture and bore gauge.

Did with a digital caliper.

 

[motomattx]

If your measuring the piston skirt you need a micrometer, a caliper is no where near accurate enough for that kind of work. Also its normal for the skirt to be larger in certain areas and smaller in others such as towards the top of the piston.

 

[kaetosgsx]

If your measuring the piston skirt you need a micrometer, a caliper is no where near accurate enough for that kind of work. Also its normal for the skirt to be larger in certain areas and smaller in others such as towards the top of the piston.

Is the shaft play at the top normal, the pistons at the bottom are rock solid... but at top... wiggle minimal... very minimal.

 

[motomattx]

Is the shaft play at the top normal, the pistons at the bottom are rock solid... but at top... wiggle minimal... very minimal.

Thats normal for them to do that.

 

[donniekak]

My fault, I thought you were measuring the bores.

To measure pistons you need a 3-4” micrometer that reads to .0001”.

The pistons will be barrel shaped, that’s how they’re made. They should be the largest diameter close to the bottom of the skirt.