[Barney Biker]

Thinking of going to a 103 on my 07 FLHT.

I have a set of 103 Cast Pistons that have the part number of 21966-070-SUB on the box
and 21989-07 on the top of the pistons. Are these the right ones for my 07 96 inch big bore?
Do I set the piston to wall clearance at .001?

Thanks
Barney

 

[Barney Biker]

No opinions on this?

Barney

 

[Don Dorfman]

Not my opinion just the design, the clearance is built into the piston if you bore a true 3.8750
Get your mike out and zero the dial bore at 3.8750
Then mike the piston at the gauge point.
Your design clearance will be directly read on the dial bore gauge when you use the dial bore in between the mike

 

[Barney Biker]

Thanks Don.
Don't have a bore gauge but I will do that when I take them to be bored.
Do any of these pistons ever show a different measurement smaller than they should be?
Thus why I am requesting the correct clearance.
Does this ever happen?

Barney

 

[BVBOB]

They are a bore to spec piston, meaning you bore to the specs listed, plus or minus. The SE 95 inch are the same way, the difference is the 103 have a small bare spot on the skirts without coating for measurement. The 95's do not. I have used a bunch of both and have yet to see a problem with either.

 

[Barney Biker]

Ok Thanks guys.
Just want to be sure with all the things you hear with the HD engine crank and cam spacer specs.
Thanks again.

Barney