Purpose of Comustion Cavity?
 

I'm a machining student, and for a project I'm making a nitro powered rotary engine to put on an RC car. I have the engine almost completely modeled, but I'm confused on the purpose of the combustion cavity on the rotary engine. Is it necessary for the engine to run or is it simply used to lower the compression ratio? If I can make an engine without the combustion cavity, I can get a compression ratio of 11:1, but creating the cavity drops the ratio to around 9:1-10:1 depending on the size of the cavity. Anyone who would know if this feature is necessary, please let me know. Thanks
https://cimg0.ibsrv.net/gimg/www.nop...40566f12e4.png

Re: Purpose of Comustion Cavity?
 

I accidentally posted this thread twice. I'm new to the forum and don't know exactly how it works, but if the admins could delete this thread it'd be greatly appreciated