"Power" valves vs. "Spark" valves

[flatheadmurre]

Sal probably has this figured out but i can´t understand how a springload on the side nr8 has will work as a spark valve...please educate me i really want to understand how that design works...
Here is a few pics of spark and power valves.
First pic is early and late design powervalve.
2nd and 3rd 2 designs of sparkvalves.

[scicala]

Originally Posted by flatheadmurre

Sal probably has this figured out but i can´t understand how a springload on the side nr8 has will work as a spark valve...please educate me i really want to understand how that design works...
Here is a few pics of spark and power valves.
First pic is early and late design powervalve.
2nd and 3rd 2 designs of sparkvalves.

Here is a link to a diagram showing how the spark valve works on a Holley 4000 (teapot). There is actually a 2nd spring inside that can't be seen, besides the one you can see on the small end. Kind of complicated, but the inner spring must be stronger than the outer one, because they are pushing against each other.
In the diagram, you can just barely make out the inner spring.


Also, the original Holley valves had the small holes on the outside of the big end. Some after market valves (in kits) had just one big hole in the center. Some also had similar holes like original Holley valves.


Sal




http://www.tocmp.com/manuals/Carbs/H...28-011_jpg.htm