Modern Oil Filter - AJS 18S

LoneStar · Post by **LoneStar** » Sun Sep 30, 2007 4:34 am

Hello all,

I've been trying to fit a modern (i.e. paper-element) oil filter to my '54 18S. I know there are add-on canisters available to do this, which hold a car filter, but they involve remote siting and a lot of plumbing there and back.

What I wanted was a modern filter which would fit into the existing oil tank tube where the felt filter normally resides (until c. 1956 when AMC eliminated it).

I've come up with a solution, and thought it might be of interest. It turns out that the Triumph T150 oil filter is the correct shape, except for locating flanges at each end that are slightly too large to fit through the top of the filter compartment. Fortunately they can be ground off with no ill effects, and it then fits nicely.

I made an adapter to fit the new filter into the tube in the tank. The adapter compensates for the shorter length of the Triumph filter. It also has a magnet to position the filter's lower end and to collect ferrous debris. The original spring (000704) and cap (000795) are retained.

Here are some pics:

http://www.vincent-hrd.co.uk/images/filter01.jpg
http://www.vincent-hrd.co.uk/images/filter02.jpg
http://www.vincent-hrd.co.uk/images/filter03.jpg
http://www.vincent-hrd.co.uk/images/filter04.jpg

I can post more details if anyone is interested. I ran this setup for 100 miles today, and the engine has survived.

Dave

wilko · Post by **wilko** » Sun Sep 30, 2007 4:46 am

great idea dave!! i knew there had to be something out there which would fit the bill! douglas

bag-o-nails · Post by **bag-o-nails** » Sun Sep 30, 2007 9:06 am

Congratulations! Dave why not forward it on
to Simon Hoskins (Tech Ed) for the jampot mag
CHEERS B-O-N

GSAX1 · Post by **GSAX1** » Sun Sep 30, 2007 3:42 pm

Hi LoneStar.

Thanks for sharing the info. I have been thinking along these lines myself and have also considered using the Triple filter. I just wonder if these filters really are better than our felt filter?

What size of particles do these filter out? Does anyone know?

Michael

Merlin · Post by **Merlin** » Sun Sep 30, 2007 4:24 pm

What sort of surface area do they have, i.e.how long would they last?

wilko · Post by **wilko** » Mon Oct 01, 2007 12:02 pm

well considering they are used for high pressure plain bearings i would imagine they would have to be a little more sophisticated than your average felt equivalent.mind you! they would have to be changed more often. douglas

GSAX1 · Post by **GSAX1** » Mon Oct 01, 2007 12:11 pm

Our felt filters are also used for high pressure plain bearings, it doesn't mean that they are good

Michael

deshollier · Post by **deshollier** » Mon Oct 01, 2007 1:18 pm

I have added a standard conversion from Paul Goff to my G9 and the filter is installed out of sight behind the panel between the tool box and the oil tank. It is in the return line, and I do know that there has been heated discussions as to whether or not it should be in the supply side or the return side, but it works fine and I imagine has a greater surface area than the Triumph one under discussion. It is not difficult to change but aided somewhat by slackening off the oil tank holding bolts. The extra hose of around a couple of feet has not caused any flow problems. The Norton Commando has the same type of filter fitted to the rear of the gearbox.

GSAX1 · Post by **GSAX1** » Mon Oct 01, 2007 1:58 pm

Hi Des.

On the pre-sidepanel machines the external oil filter is difficult to hide and also messes up the piping. I am in the search of a sollution where the existing filter cavity can be used to hold a modern filter.

LoneStar's sollution is clever, however, one should be sure that the filter is better than the one it replaced.

Michael

LoneStar · Post by **LoneStar** » Tue Oct 02, 2007 9:25 pm

Several good questions have been raised on the T150 filter. Here are some thoughts, although no solid answers.

Filter effectiveness:

An average-quality paper filter medium will catch particles down to c. 20 microns. I haven't been able to find a similar specification on felt, but I do recall reading that it lets substantially larger particles through.

Capacity:

When I change mine in a couple of weeks (newly-built engine, hence a break-in schedule), I'll cut it open for inspection and to measure the area of filter medium. With the pleats, it has more outer surface area than the felt filter - but lacks the depth to store particles in. Generally, since it lasts for a reasonable period in a 750cc triple my guess is it will be OK in a 500cc single.

General:

The T150 filters are relatively cheap, and I like the idea of just installing a new one rather than trying to clean embedded grit out of a felt filter. I can't think of a way to do that effectively, and anyhow it's no fun messing around with dirty solvent.

Cheers,

Dave