392 stroker oiling problems

Bearing 2 and 4? Is your cam grooved on the 2 and 4 journals? What bearing part numbers do you run? Are they full groove or 3/4? It's odd that 3 would not be affected if 2 was. So I may be wrong there. I went to the site for your deal...cool sounding stuff. What do you do with the throttle during the race? On full and off, or pretty much full and leave it, or do you modulate it a lot? How long are you on the throttle for the race? How long are the races? What does the oil pan look like? How many quarts does it hold? Do you turn in both directions? Does the engine or pan have an oil scraper? Is there any restriction to the heads in terms of oiling? Head studs or bolts? Are the lifter full body, or cut out for oil flow? (p/n would help)

I dont expect a factory block to live for very long making over 600 naturally aspirated. I wouldnt put a time figure on it, but expect to replace it a bit earlier than a better block. I don't usually get anywhere near that in my builds. If you have little done in terms of oil control, and those little devils pull 3-7Gs in the race, you got issues...lol.

For this crossover mod, you are basically re-routing the oil to feed the #1 main first, instead of last. So the resulting oil in that right galley is slower for the other mains. A 3/4 groove race type bearing may help solve this issue too. King p/n MB5385HP would do nicely I think. Right now, you are feeding the #1 main from the right gallery, and the left lifter galley from the same place. Without tubing the left, you have oil leaking past your lifters (normal in any engine), and the mains feeding the rods are also pulling oil, so the right gallery is a high velocity spot in terms of oil pathways. Fully grooved mains make things harder for that galley to get the volume thru there, especially if your rod clearances are a little loose for rpm (say .0025-.003). The end result is less oil to the feeds between the pressure passage "into" the block, and the #1 main saddle. Or the #2,3, and 4 mains. The mod is done like this: First, the passage in the right galley that feed the #1 saddle has to be blocked. The right galley at the front of the block is threaded for a NPT plug. The threaded plug is deep enought so seal off the #1 main feed from the right galley. Then, you drill a hole and tap it for a 1/4NPT 45° elbow into the right galley (thru the tube) just behind the oil passage bulge leading up to the deck surface. In the small flat in front of the #8 intake lifter bore. A similar hole is drilled and tapped just in front of the left side head oil feed passage, just behind the #1 intake lifter bore. Using aluminum tubing and ferrules/fittings, the two 1/4NPT fittings are connected. It is CRITICAL that the line have smooth, moderate bends and not "meander". That's about it. I would tube the left side before you do this, and make sure you drill out the left galley feed from the #1 main saddle to 9/32 or 5/16s, whatever the other main feed passages from the right galley already are. They had better not be factory drilled size (like7/32 IIRC) . You have to have them at least 9/32 or 5/16. You also want to make sure your crank journals have zero taper. Not .0001-.0005. ZERO. And install a scraper above that pan. If the heads have rollers, and the sump isnt huge (like 9-10qts in the pan) I would restrict the top end oiling too. Otherwise you're simply pumping a ton of oil up there, and G forces will keep it there for too long. That was one of the issues with the MEW engine. With rollers you dont need a huge amountof volume. Reducing it by 20% wont hurt, and will put it down to the crank and rods. What do the rod bearings look like? The back sides too... Again, King Bearing CR8008HP...