[LAU] Need to create delay or artificial latency

I have two different sized delays that I need to create. 1.) I need a audio delay of no more than 4 seconds. All of the delay plugins for Jack-Rack create echo. I just need a pure delay or artificial latency inserted into the jack audio stream (the output needs to be delayed 4 seconds from the input without mixing back the input). 2.) I need a timezone delay of no more than 4 hours. (there are no plugins for Jack-Rack that do this and my attempt to create one with csladspa doesn't work... I have plenty of hd space for looped storage.) Any help would be appreciated. Any code (C++, etc.) that would help me get this going would also be appreciated. Thank you, Daniel Bair