just wondering what this term means...

 

I'm almost positive it just means a port/polish job, where you smooth out all the sharp corners to reduce possible hotspots.

A Google search for it shows just that.

 

its means removing material around the valves in the combustion chamber

 

awsome info guys

 

when valve seats are machined the cutter takes part of the CC with it... and leaves a ridge where it machined the lip. I believe they are referring to the practice where you smooth this out.

 

Deshrouding the valves is when you cut the area around the valves. Ideally the air will make a "tulip" shape as it enters around the open valve. When the material around the valve is deshrouded, it helps complete this process.

In this picture you'll see the arrows pointing to the area that they deshrouded to help the air have more area to help create this tulip form as it enters the chamber

 

It also lowers compression ratio.

 

Gotta kinda understand the flow travel when intering the cilinder and the swirl shape and know whare material should be removed or re blended at. The quench zone is another thing too, Yeah you dont want any sharp spots and casting marks because they do create hot spots that lead to premature detonation issues.