Well, the good news is the spring and piston seemed fine, operated smoothly without issue. The bad news is that I chipped the piston a bit. You can see it in the pic. I'm not too worried. This was a small lesson for me as I have never opened up an oil pump so at least I now have a feel for it. I chipped the piston when I had it almost out.....slipped a needle nose plier inside of it then opened it up a bit to grab it internally. piston just chipped. This was a $20 M55 Melling pump. My first thought was that maybe there is a small repair kit available but now I'm thinking to just get a better pump. Why would someone go with a high volume or high pressure pump? Is that upgrade needed for my mild 350 engine? (355 4 bolt, steel crank, 9.5:1, 1.94 world heads, Crane LT-1 spec hydraulic cam)
Browsing thru my summit catalog I see many options. One that caught my attention is a made in USA summit pump with the pickup already tacked on!!!!! Great but I can't help but think, how will I adjust the pickup height in conjunction with my pan.
Another thing...Paul mentioned a kind of "blueprinting" of the pump. When I look at the main oil passage I don't think I'd be too happy putting it back in without at least burring down the edges a bit. You can see in the pic how rough they are. good idea?
just found the in depth melling article in the 'best of' section. can't seem to figue out how to cut and paste a link fom my wife's laptop here but very good info on that thread. Tried to see Paul's blueprinted pump pic but the link is bad. so....hat's the final verdict on the new m55? should I get one or avoid? personally, I don't want a 20 dollar pump in my engine.