what is cylinder quench?

i think this *might* answer yer question:
The cylinder head quench process occurs after the casting process and prior to the machining sequence. The purpose of the quench process is to remove all residue from the cylinder heads prior to machining. During the Quench Process, an elevator-type system lowers "caskets" of cylinder heads that weigh up to 15,000 lbs. into a quench rinse. During the rinse, all residue is removed from the cylinder heads.

does that help?

I think he means what is the "quench area". If so, the quench is the area around the valves that is unshrouded to promote a more efficient combustion cycle. Dan Paramore adds quench to his Stage VI head modification by adding welded aluminum material in a clover leaf style which also raises compression.

yeah, thats what i mean, thanks.

Seeing it can help. This is looking out the exhaust ports (on top). You can clearly see the two quench pads on this head, one right above the exhaust ports, and one right below the intake ports on the bottom.

http://www.theoldone.com/articles/d16a.head/2%20PO8-6.jpg

For further explanation, read this. (http://www.theoldone.com/archive/quench-area.htm) The rest of the material on that site is worth reading too. Good stuff.