Light or medium pinch
 

What you prefer?
I sent my engines to a pinch and I notice that after a medium pinch it's takes long time to do break in. I afraid the rod will not take two full break in.
Thanks

Pinching is just using some force to deshape the material of the sleeve. A lot of tension will stay in the material which can act like a spring. See it as bending a wire in a 90 degree angle but letting it go it put itself back resulting into a bend of an 80 degree angle.

A loose pinch can result into a total recover of the old shape so some pinch is needed to push out some of the created tension (the spring effect) to get a steady left over pinch.

I wouldnt refer to Ray's resizing as a "pinch" , he is a tool and die maker , a genius when it comes to resizing a sleeve and reconditioning mating surfaces

He also has a med/light , I prefer medium myself , just be very nice to the engine after a medium resize

When I resize or "pinch" sleeves I usually determine how tight it needs to be by the condition of the piston and sleeve. If the piston has a mark or scratch in it I will go tighter to get it wear back in.
Most engines in good condition I try to make similar to an engine after a gallon on it. There is no need to pinch it so tight it needs a long break in. I only recommend a couple tanks but it isn't really even necessary. In most cases the pinch will last as long as it did from new or longer.

Rex

I gave the option of light and medium because of a couple different reasons.
Sometimes guys have an engine that may have some rod or crank wear but still within usable limits and don't want to replace the parts. A Light resize will regain compression but not put as much stress on the already worn parts. Another reason some guys like our light resize is the break in is shorter than a medium so some prefer that and will accept less longetivity for ease of break in.
Medium puts the engine to near new tightness so a full break in is required as well the engine components need to be in good shape as it is going through the tightness and break in all over again.

It just gives two options for customers needs/wants.

Thanks for the comments
From now, only light pinch.
I prefer two pinch instead of one but without broken rod I the middle of the day