I never use a filter...After the engine is rebuilt and completely cleaned I just run it and change the oil at 2,000 mile intervals after the running in procedure (and oil changes) are completed...
It works for me...In over 40 years and over multiple M & B Series engines, both tuned and standard and in capacities up to 720Cc I've yet to wear out a big end...I did 78,000miles on my B33 before I rebored it for example....Ian
End fed crank
Roller big end
No real need for any oil filter other than the strainer over the outlet tube in the tank to protect the oil pump pressure side & the strainer in the sump to protect the oil pump scavenge side
Everything else will get enough oil via splash to keep it happy.
Thousands of stationary engines out there with no oil filter or pump for that matter , total splash lube .