Ahh yes, still using a table, not a delay, sorry.
Making timestretch using a delay I never tried. But probably possible.
You would need to build a fairly precise pitch shifter. The overlap add example patch in Library>Factory>Tutorials> 22_Overlap_Add_Shifter has the basics of making a pitch shifter out of a delay, You still need to do some manual labour to make it into a pitch shifter. Once you have the pitch shifter, then you can start thinking about the speed to pitch conversion.
You can try googling "Pure Data timetretch" and see what comes, I am sure yu can find something useful.
Just out of curiosity, why does it has to be not based on a table?
I am not really sure about the result you will get out of using a pitch shifter. Personally I would just go for table, as thats what most people do.