elmariachi Here is what I know from 1 motor that was built about 23 years ago. It was a dirttrack motor, SBC destroked to a 267 from 283. 9,400 rpms it would spin. This motor had a Hank the crank, chrome harded surface crank in it. It was cross drill and ran for a full season without any bottom end failure. The
oil pressure was 12 -15 psi at 1,000 rpms and go to 65-70 psi on the track. Left hand turn all the time. The rods where Carillios. Mike said that if the
oil pressure dropped to 8-10 psi the motor needed new bearings. Mike ran the NE coast dirt track like flemington, which is long gone. I did see the bearings at the end of the season with about 15 events with 3 rounds at each show. The coating was gone and you could see bronze coloring of the bearing. He said that this was the hardest bearings he could get and this is why the bottom end lasted so long. Every body had tricks back then and still do. As far as Priobe motor, he is not running the extra wide bearings. I have heard that they are not needed on a street motor, Again a GREY AREA. .080" is alot in todays world BUT may be not 40 years ago. The only reason I can fine for wider bearings is Load surface and the nascar rods could weight up to 1000 grams each. Crossdrilling the crank gave two locations to help keep the rod bearing floating on the
oil film. They also used straight oil in the 40-60 range wieght. That is thick. Today we run 0 wieght. 1 of the builders on this forum and others said that the Scat kits redid the oiling of the crank shaft. The oil is pushed in the rod bearings about 30-50 degrees after or before TDC. I forgot which it was. This pressure helps keep the bearing off the crankshaft on the compression cycle and even more important the exhaust cycle. Oil act as a cushion. Kieth Craft, Kuntz, and a couple of other pro racers would be the ones to ask about this. IMO and this not being a SBC motor, 10-15 psi would have me nervious. As long as the rocker arms are not maken any noise, I GUESS it's OK. I wouldn't let this motor idle for any length of time.
patrickt Patty my boy, I believe it was from 8-15 psi depending on motor and automobile.
If the car was idling at 600 rpm with AC running and trans in gear, the light might flicker on a 100 degree day in traffic. Again in the old days running heavier oil with cligging elements in the oil or a bottle of Richard Petty's little blue bottle.
No Pat I am not talking about sex pills in liquid forum.
STP. I do know that GM motors that had the lights come on at idle, 90% of the time came with a rod knock on a cold startup. The end was near.
Some motor lasted for years even with the knocking. My grandmother had a 57 4 door with a 6 cylinder and iron power glide. In the summer in traffic the oil light would come on and the motor would start clicking. Rockers where not getting any oil. This motor lasted the life of the car. In the old days if was pretty hard to kill a motor unless you never changed the oil.Your turn, POST AWAY!!!!!!
Rick L