Colsbeeza, that was a helpful followup and you are right on track. I also think that is correct on the puff-suck, as you really do NOT want any resistance in this. Not all filters have that rubber flapper, but it does not do anything to help us on old Brit Iron.
I would recycle that other filter to the bin-round file or some industrial application like filtering old oil for a furnace or recycling. (Or perhaps your solvent tank,, I clean mine and strain it).
Your oil fitting is a great idea, and like I said many times over, I strongly prefer a visible oil pressure gauge as it makes you into a better owner-rider-caretaker. If you know your system and whats going on internally its a great indicator of whats going on internally. On my bikes it forces me to properly warm up the machine before blasting off down the road, and I can tell by the gauge when I am ready to roll. Running a cold engine hard out the gate is a cruel thing to do.
While on some car applications your clear plastic line is acceptable I would suggest you replace it with either a good oil compatible rubber-nitrile line or a commercial grade braided stainless line. (There is some economy grade stuff out there that is easy to work with and affordable). While hotly debated in the NOTRUN community, I have several friends and old shop customers who had bad experiences with the plastic oil lines on NOTRUN/Nortons as they came stock with a rocker feed line out of plastic.
In Rons case, his had a pinhole leak and lubed up his rear tire and luckily he was at low speed on a side street, bike went down hard. He still shudders to this day speculating what would have happened if he had been on the interstate freeway.
While yabbering about oil systems, Ill mention this as its a little related but off a bit on a tangent. Most British twins LUBE the top end with a oil line or T fitting off the oil return line. In most cases you will notice the main return line is approx 1/4" ID, but the T fitting or take off for the rocker feed is a smaller diameter. Most bikes its crudely done and intended to prevent over oiling. But as I said, return oil is heavily aereated and surges and pulses erratically. Not to mention without a return line filter,, its also grotty,soiled and dirty possibly containing swarf, or in some cases friction material from the clutches. (Some unit models share the primary oil with the engine). NOT BRILLIANT ENGINEERING.
So, while its simple and functional if you do testing, oil reaching the top end can be intermittent, and belaboring the point, when cold it can take a long time to get up there. The top end needs a Goldilocks amount of oil, not too much and not too little. Those crudely brazed or soldered T fittings are not exactly calibrated or precise.
The BSA B50 community are really big on modifications to the top end rocker feed, and I wholly embrace their thinking on this topic. Its well documented and they use a calibrated carb jet to meter the precise amount of oil needed and they take a pressure feed right off the main oil pressure passage where you would expect the oil to be clean and a good flow rate as well as consistent.
See:
https://www.b50.org/mods.htmCCM BSA race bikes also do this mod, and well documented and illustrated here.
See:
https://www.b50.org/ccmmods.htm(Clever lads they are,, Rupert Ratio in his books also is chock full of helpful and informative tips such as this, and thought I would give him a nice endorsement here)
So,, While this goes against the grain of the rivet counters, and "Stock is best!!" It is sound principles and logical modifications for a bike that can use all the help it can get in oiling. I highly endorse it and strongly suggest these mods to any who will listen.
So, I had some interesting interactions about 10 years ago with several owners of the later Triumph TSS bikes and while not a common machine, these have the unique cyl heads.
" Designed to appeal to the US market, the TSS had an eight valve Weslake Engineering cylinder head developed by Triumph's Brian Jones from a 1978/9 design originally commissioned from Nourish Racing of Rutland[1] following 1960s designs for the 650cc twins by the Rickman Brothers."
Wiki here,,:
https://en.wikipedia.org/wiki/Triumph_T140W_TSS(I always wanted to play with some of these heads and never got the opportunity) But a number of owners were complaining that they had abnormally short cyl head life and extreme wear problems. The modification that did the trick was reported to be the oil feed for the top end modification I pointed out here.. The reports on this is that the wear problems went away.
While an old cast iron top end Beesa can chug away seemingly forever on the faintest whiffs of lube,, it does seem like any motor can benefit.