I received a reply from Champion Labs today concerning the center tube concerns. Below is the text of what they sent. Posted with their permission.
Dear Mr. Hackett:
We wish to thank you (and all of the "bobistheoilguy" forum participants as well) for returning the Super Tech oil filters and bringing the center tube perforation opening concern to our attention. We routinely monitor this website for concerns and take every comment about our products seriously. It's apparent that some of the forum participants are nearly as passionate about filter design and performance as our own Engineering design team. In fact, this is not he first instance in which we have taken prompt action to correct a customer concern thanks to website conversation.
Prior to receiving your samples , we had begun the evaluation of the perforation pattern, when the "SuperTech WM Filter Help" thread originated on January 5, 2011. We determined that the tooling wear and subsequent material build-up on the perforation punches were the root cause of the problem. The perforation punches were replaced on January 7, 2011. In addition, gaging and inspection procedures were revised and now utilize a "no-go" pin gage to check for minimum perforation size. Flow restriction testing performed in our laboratory with questionable center tubes showed showed restriction of finished filters to be acceptable, although slightly higher than normal.
The center tube of the SuperTech ST7317 filter that you provided has an open area of .27 square inches. The inside diameter of a 20mm threaded Mitsubishi mounting base stud has an open area of .21 square inches. The element assembly that you provided was resealed in a new shell and baseplate assembly and flow tested for restriction. We found the restriction to be 1.0 psid at @ 2/0 gpm and 2.0 psid @4.0 gpm flow. A filter with the correct opening pattern was tested for comparison. Restriction was 0.8 psid @ 2.0 gpm and 1.4 psid @ 4.0 gpm flow. Although the flow restriction was slightly higher than usual, the flow eould be adequate for this type filter and service application. The specific filter does have an integral pressure relief valve with an opening pressure of 11 to 17 psid.
Thank you again for your participation in helping us correct this manufacturing concern. We appreciate and respect comments from our customers that help us to produce the products they expect. Please review the enclosed service report. Should you have additional questions or concerns, please don't hesitate to contact us.
Sincerely,
Don Rigg
Technical Information Director
The test results:
1. The media in all three filters was dry.
2. The ST7317 was already cut open prior to being returned.
3. All three filters were visually examined. As reported, the louvers in the metal center tube are shallow. The perforations were measured an confirmed to be below our minimum perforation size.
4. The center tube from the ST7317 was removed and reassembled using new endcaps (without the bypass valve) in a new shell and baseplate assembly for flow restriction testing.
5. The reassembled filter was flow tested at 2.0 gpm and 4.0 gpm using SAE 30 at 180F. The restriction was 1.0 psid. and 2.0 psid., respectively.
6. For comparison, an identical type filter with the correct opening pattern was also tested at 2.0 gpm and 4.0 gpm. The restriction was 0.8 psid and 1.4 psid., respecively.
7. Although the laboratory results confirm the center tube with the shallow perforations do exhibit a slightly higher restriction to flow, the flow is adequate for this type filter and application.
Although the shallow perforations are cosmetically undesirable and below our specifications, the filters are completely functional.
Ed
