Upgrade BI server to 2014 and stay on 2008r2 with the database engine server

We would be happy to upgrade our SQL Server environments to 2014, but we have a tight budget for next year. Our BI server (SQL Server 2008 Standard Edition, that is used only for BI purposes) is located separately from the Production Database server (SQL Server 2008 Enterprise Edition). The BI server contains our SSIS and SSRS packages and reports. I was wandering whether it's possible to have a configuration where the BI server will have SQL Server 2014 (Standard of Business Intelligence) but the database server itself will remain on 2008. Thanks for your answers, Roni.