They WILL fit, but not in the way you want them to; you'll have to cram them in to the point where you can't get them out of the Porper anymore. I suggest buying the E Porper for that, or buy a normal pack of bikes and use the D&D Porper to extend the lives of those a bit.
In short, no. As blue shirt said - they can fit, sort of - if you jam them in permanently. It might be a little easier if you only use 52 cards. Not recommended with 54. Not recommended period, actually.
Well, MY maters deck (*whcih I got free for submitting the best 'super-hero' based presentation, Ahem*) barely even fits into the masters clip (*see above*) I got with it! So I would doubt that it will fit...