School me, what makes a motor a Wedge?

[DartGTDan]

As the title suggests, what makes a motor a wedge motor? Is it based on the V-design? Head seign? Any cubic inch displacement minimum/maximum limits? Also, what is and what makes the 318-Poly a Poly?
It's early, and inquiring minds need to know.
Thanks

 

[1MeanA]

I believe both the wedge and poly names refer to the head design (polyspheric combustion chamber)

 

[abodyjoe]

The combustion chambers are wedge-shaped

 

[HotLines]

Most any V8 is a wedge except for Flatheads and the Hemispherical depending on how you look at it

 

[toolmanmike]

Right you are friends. A wedge has a wedge shape with the valves in a row. The Hemi is a hemisphere shape or a dome shape with the valves on opposite sides with the spark plug in the middle. The poly is semi domed shape like the hemi but the valves are ofset for more efficient flow. It also makes them cheaper to produce. Here's a interesting article about the poly and the Hemi. http://www.streetrodderweb.com/tech/0805sr_vintage_engines/index.html

Here's a visual of the differences of the big 3. The first image is the Hemi. The second is the Poly, and the third is the wedge.