Twin external oil filter connections...

[rayswadling]

Hi,

I have a 1964 G12CSR engine that I'm rebuilding to replace the 1959 engine fitted to the bike.
As it's dismantled, seems an ideal opportunity to modify the cases to use an external spin-on oil filter on the pressure side.

I've read the tech articles, and can see how to create the take off from the pump via the drilling to the oil filter housing after its been blanked off.
This then bypasses the entire standard fitting oil filter so the chamber can be left empty.

What I can't quite understand is the return from the filter. The article shows the cap modified to take a banjo fitting,but that would then bypass the spring-loaded ball valve in the cap itself?

Is that right?

Does this ball valve have to be removed/blanked off at all or is it just OK with all the pressure from the "wrong" side? I guess my concern is that pressure from the wrong side could force it out of its housing.
Is this just a non-return valve or does it have some other function? What (if anything) is needed to replace it's function?
Alternatively, what about connecting the return from the external filter back into new connection drilled into the old oil filter housing? Oil returning from the new external filter would fill the old chamber (no felt filter installed) and then exit via the ball valve as if it was the standard setup.
It just looks like it might make the hose runs a bit neater that way.

Cheers,

Ray.

[wilko]

I vaguely remember the picture of the setup you mention but it seems overly complicated.Have you considered modifying a Triumph triple paper filter to suit the existing setup? Maybe i'm confusing this with a Velocette mod.

[Eric]

Ray if you connect your external filter to the modified cap with a banjo as you describe that's it. The non return valve will just help to stop oil within the engine from draining out when the engine is stopped, that is its original design function.

e.g. To allow oil into the engine from the filter tunnel but stop it coming back out.

[griffin]

Ray while you're at it why dont you have groove machined into one half of the crankcase around the filter tunnel and fit an 'o'ring ?? This will replace that pesky paper gasket.