My little rant on oil filters
First, I'll say this.... The Triumph (twins) dry sump type engine is one of the very few engines with a piston type oil pump with spring loaded check valves,( that's why BSA's and Norton's sump the engines with oil, and Triumphs twins usually don't ) most all other engines in the world have a rotary gear type oil pump. and rotary pumps usually don't have check valves.
A filter in the feed line won't work, the piston pump will draw off the oil between the pump and the filter very quickly and then it will cavitate the oil pump causing the pistons and check valves to run dry and loose suction and wear out early, the Triumph pump likes the oil to be unrestricted and gravity supplied to the pump.
A filter does on the return side does not work that well ether, because the Triumph pump being a piston type pump on a dry sump engine and it sends pulses of oil mixed with compressed air back to the oil tank (sometimes foam). that oil foam mixture is supposed to sit in the tank and separate out the air.( that's why they put a froth tube on the oil tank ) all that foam is now send into the filter, and oil filters like liquids, not foams.
It's different for the Nortons, Triumph singles, Triumph tripples, Harleys, and BSA's with a rotary oil pump that does not pump nearly as much compressed air mixture in with the oil.
I like to learn new stuff everyday, so if you have something to add to this, let me know.
The Triumphs twins have been running just fine without filters for the last 70+ years, why mess with them, ( the non detergent oil thing can be discussed now ). Just change the oil now and then and you'll be fine, I would rather pump dirty oil through the engine than no oil at all.
Oil filter kits for Triumph twins are just a marketing gimmick, designed to filter the money from your wallet.
Last edited by Torch; 05-25-2012 at 1:53 PM.