Judging from the specs, you should be able to, yes. This assumes, of course, that M-Audio's drivers work correctly in such a configuration, but... they certainly should, anyway....
On the FW1814, set the digital I/O to S/PDIF mode instead of the default ADAT lightpipe mode. Next, hook up either optical or coaxial S/PDIF (whichever you prefer) from the output of one to the input of the other. Finally, switch the second device to use external sync from S/PDIF.
You don't need to daisy chain them together. Just get them both working seperately and then in your m-audo control panel, be sure sync is set to internal. They use the same ASIO drivers, so your app see them as one large group of inputs.
Why not? They both have S/PDIF. Unless there's some idiotic software bug in the drivers, there's no reason in the world you should not be able to make them work together.
EDIT: Oh, I forgot. We're talking about M-Audio's drivers....