I am installing a new oil pump in a motor I am building. It is a 1275. Are these pump self priming? This is a brand new build so I would think I should fill the galleries before initial start up.

I usually fill the oil pump with Vaseline. It'll stay in there until you go and turn the engine over, then will melt away when the engine warms. When it comes time to spin the engine over, pull the spark plugs and let the engine build up oil pressure.

and fill the filter with oil.
Roy

That raises another question: I am making adapters to move the oil filter off the motor and onto the firewall or other suitable location. Which is the supply for the filter and which way does the filter work? Does oil enter the center of the filter and exit the periphery or is it the opposite? I assume the lower outlet on the motor is the exit for oil and the upper outlet is the return?

Oil enters the outer part of the filter and exits the center section, you are correct everywhere else, oil comes out of the block back by the battery and reenters the block at the current oil filter.(Actually I think that you had that backwards too).
Bill

You might want to look at http://www.nonlintec.com/sprite/lubrication/. I worte this specifically because I kept seeing questions on the oil circuit, and the shop manuals never seem to address it.

Nice article. My early 1275 has the oil priming plug. My later 1275 does not.

Really nice article Steve. Thanks for posting.

Perfect article. It has answered all my questions. Thanks