I'm trying to figure out what my piston to deck clearance is on my new built JGE block that I just received. I'm measuring this with a dial indicator I put the tip on the edge of the cylinder zeroing out then slightly turning the indicator so the tip lays on the piston flat surface. Then rotating the crank until I get the least clearance. On cylinder #1 I got 0.004" on the intake and 0.014" on the exhaust side. Now what is my actual clearance? Should I average the two different values? Or am I doing something wrong here? Is this OK to measure different clearances on the different sides? The pistons are CPs, BTW. Any input is appreciated.

 

Is your deck level when you are measuring (not tilted more to one side)

 

No, it's not. So that's what's messing up my clearances. Thanks for the advice, I'll level the block and then remeasure everything.

 

Depending on the piston to wall clearance, the piston may "rock" slightly giving you different readings...
Not absolutely sure of the correct way, but I would go with the smaller #'s just to be safe...

 

Has your block been decked. Wonder if it has been if it has a slant to it? Not sure just an idea.

 

Yes, the block is decked. Piston to wall is 0.0030".
I leveled the block and remeasured everything. These are the readings I got.

Cyl INT EXH

1 10 11
2 17 16
3 10 18
4 8 8

The numbers are thousands of an inch on the intake and exhaust side. I repeated several times and got the same readings. Now someone please help me decipher these numbers. Why do I get so inconsistent readings in the different cylinders? I'm totally lost here...

Here's how I'm doing it

 

either your indicator is getting moved/bumped.
your block is not flat.
your crank has 4 different strokes, your rods have 4 different lengths or your pistons have 4 different compression heights.

i'd guess option #1 though.

with your indicator on the pistons rock it and use the tightest reading