1377 valve

[Hung2]

The older valve had a metal valve stem head whereas the new ones have a Teflon head. Does the metal head give a better sealing? Did Crosman change the metal to Teflon just for cost?

[bgmcgee]

I honestly can't give you a definitive answer but the new stem works very well.  If you think about it with the all nylon or what ever it is this makes it a tad lighter which I would think should improve performance.

[Hung2]

What are the school of thoughts on reduced valve volume vs enlarged valve volume? I thought a reduced valve volume with the same # of pumps would yield a higher out put pressure whereas it would be the reverse for an enlarged valve volume. Correct, yes or no?

[DBOdude]

http://www.mp661k.com/sitedocs/13xx_HotRod.pdf

[WyoMan]

Here's a resource that a few have read...
http://www.crosman-air-pistol-owners-forum.com/board/index.php/topic,11146.0.html

here's another resource:
http://www.network54.com/Forum/275684/message/1358401495/Pressure+%2A+Volume+Energy%85%85..

answers to your question will require explanation of barrel volume / valve volume, pump stroke efficiency, transfer volume...etc...likely to cause more questions. Best to research a little 

the short answer is don't reduce your valve volume

for sealing surfaces in a knock open valve, the harder the surfaces the better...less static friction. That also means tighter machining tolerances and better gun building materials (i.e. brass instead of aluminum)...hth

[Hung2]

Thanks guys. I will take my time to digest all the info.