Oil pump plug-help

[stkmtr]

I just finished plugging my oil pump for full flow. It is a cast iron melling and I used a 1/2 NPT plug. I know these are tapered to prevent leaking. I am also aware that if overe tightened they can crack parts. I tightened the plug firmly and reassembled the pump to find that it will not spin freely any more. Doses cast iron warp easily. Should I try to machine it and if so what should I use to do so-We have a bridge port mill ans a lathe-I feel that tossing a 50$ pump is a waste and how can I prevent this from happening again?-ss

[Oliver Knuf]

That's easy, when I understood you correctly. Take a look! I think, you went to far inside with your tool to make the NPT thread, so the inner pump body where the gears run over, is slightly damaged. The area under the pump outlet is important. Maybe a little edge is bended, just clean the edge with a fine files, maybe a piece of fine sandpaper would help, too. Put the gears in and if you turn them with two fingers, it has to move easier. make it as long, as you feel something rough, clean all parts after every grind! That's it!

[stkmtr]

Sure enough there is a small bur binding the pump above the section that was thinned out by takeing the tap to far. In thew past I have always bought my pumps pre plugged. If any one else does this donot tap the inlet side all the way to the inside area as the lip between the hole and the gear thins out leaving it prone to bending. I'm gonna file this lip down-I'll write again if I can save it.-SS

[stkmtr]

It seems that this pump was poorly machined to start out with the quality is awful. What is the brand that Berg uses? Shadek? Do you like the cast iron idea and will I need to modify the oiling system. AS-21 fullflow??

[Oliver Knuf]

Berg uses Schadek, but only completely blueprinted and machined for FF. The cast iron pumps don't seal that good when the engine gets hots, as cast iron differs in the expansion rates from aluminum.