Probably of limited interest to most, but some of you may remember/have use d these... I have two of them; one was given to me by a friend ages ago an d is probably at least 15-20 years old; from back when they went by Canton/ Mecca instead of Canton Racing and CM Filter. The other is a couple years old, purchased when I got my Heep.
It's oil change time and I'd happened to come across the old one while sort ing all of my stuff; they're both disassembled for a cleaning now. I'll gi ve one to a friend and keep using the other on the Heep (oddly, they're bot h 3/4" thread; the old one was purchased for a WCVW engine, either a GTI, S cirocco, or Corrado G60.) The interesting thing that I noticed is that whi le they look as if they're constructed similarly and use the same seal kits , the seals are inverted on the old one; instead of having the O-ring at th e base end and the big flat seal at the end cap end they're the other way a round, and the big flat seal was apparently acting as an ADBV for the filte r. CM's current literature explicitly states that their filters do NOT hav e ADBVs and in fact the newer one doesn't. It's not an issue for my curren t application but I'm thinking that I might keep the old one in case I ever need to use it in a base down configuration.
Wonder why they made the change? Restriction to flow? Never heard of anyo ne complaining about that with any C/M filter, but I suppose it's possible. ..
nate