Finally got to tear into a motor I've raced on the dirt track. I've run Delo 400 15W-40 almost exclusively. Motor is a 402 BBC. Steel crank, 7/16 rods, Federal Mogul tri-metal type bearings, KB hypereutectic pistons with around 8.5:1 compression, Crane flat tappet hydraulic cam, oval port heads with small valves, hard seats for exhaust, stock type ball pivot rockers, standard volume oil pump modified for higher pressure, homemade oil pan (based on factory truck pan) with trap doors and windage screen and right side extension, cast iron exhaust manifolds, high rise cast iron intake manifold, Q-jet and HEI. Rod and main bearing clearance 2.5. Self imposed RPM limit of 6200, with occasional forays to 6500. I did not have this engine balanced; after weighing parts and crunching numbers, I determined that with the bigger rods but lighter pistons I was at 51% to 52% overbalance. Fuel was 93 octane pump gas with no additives. We were allowed to run race fuel sold at the track but I figured I didn't need it given the CR. This engine was in a stock type class that allows a few modifications. The big block was legal for the type of car. I put almost two seasons on it. Missed a few races for work, crash damage, etc. During that time there were no failures of engine internal components. I did have one rocker nut that backed off and caused a dead cylinder but that was a lock nut issue. I had more power than I could put on the ground. Modulation of the throttle was necessary to control wheel spin. Basically, it ran fabulous and I had more power than the rest of the guys, who were running small blocks. However, being 400 pounds over class weight and all of that being on the nose is detrimental to cornering performance! Lots of fun though....... Oil fill was 7 quarts of Delo400 15w40, both old and new formula, along with about half of bottle of STP blue, which seemed like a good idea, but in retrospect probably was not necessary. Filter was a Delco PF-935. The oil filter bypass was left intact and functional, albeit with a heavier spring. I changed the oil around 15 race nights or so, each of which include a heat and a feature and packing the track. Examination of the bearings revealed a polished look to the first layer of bearing material. There was no wear through the first layer. The part of the bearing near the cap parting line, where the bearing thins slightly, was untouched. There was no pitting, spalling or galling, just some minor light scratches in a few places. I was surprised by the condition of the bearings. During a feature in May of last year, the oil filter got knocked off the filter pad due to running over a ridge at the very bottom of turn four that was left from track grading. (The oil filter sticks out about an inch and a half below the oil pan, not a great situation but neither here nor there) I ended up cross ways in turn four after spinning out or tangling with another car or both, I forget. I quickly backed down into the infield to get out of the way of oncoming traffic. Didn't look when I took off again moments later. I made it about 3/4 of a lap at race throttle before I noticed the oil guage reading about zero! (This is where a low oil pressure idiot light becomes useful) I immediately shut down the engine and coasted out of the way. The following week I debated pulling the oil pan and doing some inspecting, then decided to put on another filter, refill and see what happens. It sounded ok on start up and had same oil pressure as before. I decided to keep on keeping on and it made it with flying colors. Conclusion: Delo is good stuff!