Download a bootstrap.
https://bitcointalk.org/index.php?topic=623147.msg9772191#msg9772191

Also for syncing I noticed, that having multiple connection to other nodes creates "ERROR: ProcessBlock() : already have block  XYZ" and trigger lookups for Orphan blocks which slows down the synchronisation.
I usually reduce the maximum connections while synchronizing to have only one source and not get ERRORs and ORPAHNS.
Set
maxconnections=1
in clam.conf and restart the client

Note: There is slight chance you get connected to some malicious node and you download forked chain, but I never encountered that. Plus after you finish syncing you can check the hash of the last block with some public clam block explorer.

Note 2: The sync takes some time to finish, depends on the CPU of you machine (it basically verifies whole chain on the fly) - it can take few days (when I tried to sync using Raspberry Pi in January, it took a week to fully sync)