[miller91]

Well, the Frantz is a well known old accessory, seen them advertised in old magazines. Gotta say that toilet paper when soaked with anything is pretty impermeable. I think the Frantz started a sort of "urban legend" that all canister style bypass filters can accept a roll of toilet paper. Bypass filtration depends on flow, I am with JSeery on this. Modern diesels still use bypass and cartridge filters, the construction is practically identical to the original elements. Generally there are two styles available; pleated paper and "stacked disc" media. For instance the Fram C4 is pleated paper, the C4P is stacked disc media which is actually pretty good stuff and is what I use. Bypass oil systems actually work, as I said fleet trucking still uses this same technology, diesels produce sludge like the flatheads do so they, like the old canister filters did, clean a portion of the oil through a bypass filter eventually filtering all of it over time, (and in a shorter time than you think at cruising speeds). Sludge is an organic contaminant, stacked disc media loves to bond to and remove this material. Other damaging particulates are inorganic contaminants and can be removed very effectively via bypass, while full flow cartridge filters by their very nature (full-flowing) tend to allow smaller micron particles to pass through. Bottom line is that bypass canister filters work but not with no-flow toilet paper. While our old car's engines did not come with ideal oil filtration, it's not as bad as they are made out to be. The proper filter cartridges are cheap.