View Full Version : Remote oil filter

05-16-2012, 8:08 PM
Anyone using the rat hole remote oil filter?

05-23-2012, 7:19 PM
im using the MAP remote filter, works great and nice design, what is the Rat Hole filter?

05-23-2012, 8:12 PM
Don't know what the rat hole filter is, I'm using a generic spin on filter housing like that commonly used on Commando's. Got to make sure you replace any paper/ fabric filters with gauze so you don't stifle the flow when contaminated. These remote filters work great but a filter in the feed line would be better.
3" exhaust clamp fits my OIF.


05-23-2012, 10:00 PM
Saw one on ebay, Rate Hole Filter

05-25-2012, 8:38 AM
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.

But, IMO....
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.

05-25-2012, 10:13 AM
Again Torch is the voice of reason, I was going to run a remote filter when I started gathering parts last winter, but instead used the housing as part of my tail light. Now I'm glad I did.

05-25-2012, 3:18 PM
My bike has the Kirby Rowbotham oil filter kit,which after some mods to the timing case and oil lines, places the filter between the pump and engine.After several years,seems to work ok.

05-25-2012, 5:26 PM
I usually agree with Tony,but I don't think he has thought this all the way through. First, filters handle "foam and liquid "just fine. Second,Triumphs twins have always had oil filters,it is a centrifugal filter built in the crankshaft ,also known as the "sludge trap". This works great for the rod bearings,but does nothing to give "clean" oil to the rockers and(on certain years) the EX tappets. A return side filter cleans all the oil as it exits the motor,so the rockers get clean oil and the oil in the tank is clean. But, the main reason it is a good idea is that the sludge trap doesn't fill up cause the crap is filtered out before it gets to the trap.I have been putting MAP return side filters on for years and have never had a sludge trap issue or oil pressure related problem. Jack

05-25-2012, 7:58 PM
you are right, it already has a filter, and that oil going up to the rockers is return oil that has likely just come out of the crankshaft, so it's been filtered once.
I guess it doesn't bother me too much to pull the engine and clean the sludge trap every 10/15 years.

Make's you wonder how hell all these old Triumphs ever survived all these years without them.

05-26-2012, 8:47 PM
Well it does bother me to split the cases just to clean the sludge trap,so I run a filter so I don't have to. These old triumphs survived because they are a good simple design and they got rebuilt a lot. re-cycling dirty oil to the top end adds to faster wear. I can understand you not caring for filters as you have stated before you employ 2 fulltime engine rebuilders and a supply of clean oil to the top-end would be a bad thing. Jack