old stock valve test

[Koa]

the one on the left is stock out of 16,264
one on the right i have no idea, i thought sherdian or old palmers

i tested these 2 valve and another newer valve that looked like the one on the left but with a bigger output

Mysto, Old Stock, Newer old Stock

with psi at 450, and main spring adjuster the same (old style)

newer old stock 210 fps
old stock 260
mysto 310

also the port Diameters and Areas were something of note

stock stem
dia 5/32
area .019

mysto
input .24, output .20
input area .045, with stem .031

Old Stock
input .26, output .185
input area .053, with stem .027

Newer old stock
input .26, output .24



mysto valve with the stem has .005 smaller input than output
old stock valve with stem has .007 larder input than output

i have a KAPP valve stem that is a .007 area
when i dial it in with the mysto valve they are the same so it might help
have yet to try it





UPDATED
the Mysto valve is just another stock valve....WGP has many types

the KAPP valve seal was too soft and wouldnt open under higher pressures

[Koa]

i have discovered another old stock valve that is similar to the stock valve i reviewed on the right

similar in shape the tip of the stem guide is threaded, and came with a brass stem

Specs are:

Input: .235ish
Output: .203ish

this valve got 20-30 fps more than my custom valve....now to see why

[Koa]

this valve got 20-30 fps more than my custom valve....now to see why

i know why....THE DEVIL!!!! no no
it was the springing, it was tested with a Blue main from maddman and a light sear spring strength for the valve.

The stock valve has bigger openings and a larger volume, so when its opened WAY too far and long, it will flow more air

But when we used a Stock valve and a yellow main, the results were more inline on what my valve is made to do, which is open easier than a old stock valve with the bare minimum spring forces.

woot for me!

[Koa]

im gonna attempt to fill in the excess volume on both of the turned valves and see if there is any improvement to FPS over original design, and how close it comes to the mysto stock valve