With only 1700 miles on a fresh rebuild, you've got serious problems somewhere. I'm going to guess your machine shop made a mistake on the crankshaft regrinding and put WAY too much clearance in there, on either rod or main bearings, or possibly both. Did you do any kind of clearance checks during assembly, such as using Plastigauge? Ideally, the oil clearance should be about .0015" (1 1/2 thousandths). If the clearance is over .003", you'll have hot oil pressure problems unless a very high-volume oil pump is also used. On the round trackers, we used very wide clearances and high volume pumps, but those engines were "worn out" after less than 1,000 miles. The clearance was built in to allow high RPM with very low drag, and if the bearings got pounded out after a short time, we replaced them after a few high speed laps. It was time for new rod bearings after 800 racing laps, about 400 miles at speeds of around 7,000 RPM.
Jerry
