I have been looking at fitting a Norton Commando type oil filter to my ‘58 Golden Flash. I really didn’t want to fit it in the tool box, firstly because I carry tools and secondly because I don’t like the idea of a filter, with its two connections, hiding where you are not going see if they are starting to leak with a view to letting-go altogether! Placing it behind the gearbox, where Norton put it, would have been nice but the filter won’t physically fit because the gearbox plates are too close together. I wasn’t too keen on the spot between the engine and gearbox as this area would make primary chain (gearbox position) adjustment awkward.
Eventually, I decided to take the lead of Royal Enfield and their 650 Interceptor, where they place their filter between the front down tubes.
I made up a little mounting plate that picks up on each side of the bottom stud on the front engine plate and hung the filter from that.
The result is a filter that is easy to get at and with no limitation with regard to size of cartridge. It can easily be replaced without making a mess and in my view, doesn’t look out of place; and I nearly forgot, as it is in the air stream, you get a little bit of oil-cooling too!
It needs to be tucked up as close to the bottom of the engine plates (0.8” from the centre of the stud to the filter fixing surface)as possible to facilitate an easy turn of the bottom hose that isn’t hampered by the right-hand bottom frame tube; I also placed my filter slightly left of centre for the same reason. Incidentally, the fixing stud hole on the filter mount are 5/16” UNF not 26tpi as some sellers say!
Despite using fairly thin sheet for my bracket (about 1/16”), the mount is very rigid and you could use plenty of force if the filter got really stuck!
