I abandoned my engine break-in Saturday after five minutes due to an oil leak. Only lost maybe a 1/4 of a quart. Up to then it was running nicely. The first few seconds at idle the pressure was around 30 lbs. We then immediately started break-in, running the engine at 2000-2500 rpm and oil pressure was 70-80 lbs. After five or six minutes, we shut it off without incident other than the leak. The leak turned out to be a stupid mistake: I incorrectly had the cork seal not sandwiched between the adapter and the block.
For the engine build I set bearing clearances between .0015 to .002. Oil pump is a stock Melling, not a high pressure or high volume, just stock. For break-in I was running Rotella T 15w-40 and Red Line Break-in Additive and a Wix filter. A "Chevy" guy I know and trust thinks the 70-80 lbs is too high, says at that high of a pressure the oil is forced out of the sides of the engine bearings causing them to wear prematurely, and forcing oil up into the cylinders which could cause issues with the rings not seating properly. He suggested using a thinner oil, a straight 30w or 10w30 and looking into maybe something wrong with the oil pump.
Any opinons??
For the engine build I set bearing clearances between .0015 to .002. Oil pump is a stock Melling, not a high pressure or high volume, just stock. For break-in I was running Rotella T 15w-40 and Red Line Break-in Additive and a Wix filter. A "Chevy" guy I know and trust thinks the 70-80 lbs is too high, says at that high of a pressure the oil is forced out of the sides of the engine bearings causing them to wear prematurely, and forcing oil up into the cylinders which could cause issues with the rings not seating properly. He suggested using a thinner oil, a straight 30w or 10w30 and looking into maybe something wrong with the oil pump.
Any opinons??
