Error: "The size of the request headers is too long"

While querying the /data/query API, I am trying to get the value of all the fields in the Project object through the CZQL query. I get the message "HTTP Error 400. The size of the request headers is too long."

Has anyone experienced this error? When Clarizen says the request header size is too long, it means there has to be hard limit. Does anyone know what that limit is?

Thanks