My cylinder bores are .0017 larger than the 96mm Keith black hypereutectic pistons I am using. Is that to tight for street use? I did looked at the Keith black recommendations and is says on to use a clearance of .003-.0045. on pistons with a diameter of 4.000-4.100. But the chart they have does not have a recommendations for pistons smaller than 4.000. 96mm pistons are 3.7795.

How are you measuring? You measure the piston at the bottom of the skirt.
I know the KB's are sloppy as hell and they grow in the first 30-60 seconds to the correct size.
I can't remember the tolerances, but the .003-.0045 sounds to small.

Question: 96mm Keith Black Piston to Cylinder Clearance? Is .0017 P/C clearance to tight for street use?

Contact the manufacturer for a clear answer to your question.

It may take you a little bit more effort, but you sound like you would like direction that you can bank on with no advice.

Take the time to reach out to the manufacturer for guidance.

Don't be lazy and rude, two bad qualities.

Also, what are you measuring with? The 0.001" you're looking at is pretty small for cheap instruments.

Report back when you talk to KB. It might save someone else a bit of time.

I used several sets and I said I think .003- .0045 might be too small...so what do you think .0017 is?

I am measuring with a Fowler Dial Bore Gage - Model: 52-646-300 Measuring Range: 2 - 6" Graduation: 0.0005".
Click to view attachment

Ask George at EMW.

I suppose that you are using Hasting's rings? What cylinders? I have learned that different cylinders demand different total clearance due to expansion differences through the first 2-3 min of run time.

We usually saw the KB pistons at 3.777- 3.778" and I'd set OEM bored cylinders to 3.780 and we'd be golden.