Oil Filter Top Difference

[BigLakeBob]

Attaching two pictures. Top on left-the relief valve is in the exit hole. The center and right top the relief hole is over more and has it's own hole back to filter center. Does anyone know the reason for this different location? Also, the top on the right has a steel plug in the outside. It looks as though the hole connecting to the valve is drilled at an angle from the inside(on all of these covers) and perhaps the drill went through on this one and was plugged instead of scraping it? Any thoughts on these differences? Thanks again, I appreciate the input. Bob #6738

[bmh]

In looking through my pics of original machines I noticed a couple of things. First, these filters don't appear to have been a favorite accessory for most. I was surprised at how few bikes had them installed. Second while I had noticed the little welch plug before, I never gave it any real thought. In looking I see that the welch plug was an early detail, looks like it disappeared in the mid 50's sometime. Another thing I noticed was that the filter tops I have seen installed on 48's have the welch plug sealed from the outside with something like Gasolia.