[Jay S]

It would be helpful to expand on what you are planning on doing with the engine and how long the engine will see those rpms. As the engine rpms increase friction increase, so does heat. That require adjustments also. The red line might be a lot different depending on what your doing. When we built Pontiac 455 circle track engines that would turn 5500 to 6200 or more, for a lot of laps we had more oil clearance, a lot of oil capacity, irc almost 12 total qts, oil restrictors on the lifters, baffled pan, mesh windage tray, huge remote oil filter and a 2 quart accumulator. I would be more concerned about those things than the forged internals giving out if you spinning it very long. Smaller engines we pushed to 7k. That is nothing compared to what the big boys do. Lol

Each part in the engine has an engineering safety factor. When I went to school and had class’s at the tractor test lab on industrial equipment we also had duty cycle’s to further evaluate parts. I guess old habits are hard to break, I still use a duty cycle. But I do quite a bit of industrial engineering. For finding a general number for max rpms using mean FPS on pistons a starting place is 3500 fps for cast pistons and 5500 FPS for forged for drag racing. Then used a 80% duty cycle for intermittent (circle track). 60% for continuous duty(marine and industrial). Gets you close to a red line, or at least a starting point depending on the engines internals.

Max RPM = Mfps x 6 / stroke x duty cycle

I don’t ever recall reading about Pontiac’s dyno testing as far as times and the level of output used. It would be cool to see someone’s first hand experience. I have read about Chrysler engineering and first hand accounts from the dyno operators. I remember one said they did a 13.5 hr brake in, then they would service it and pull it on the dyno for 1500 hrs. I assume they did that at full throttle and rated rpm with the load cell set at that point. I saw the dyno paper work from the guy that did the the dyno work, had a net number and a gross number from the pull. One was 4800 rpm and the other was 5200. He said after 1500 hrs the engine would pick up some hp, then shortly after the crank would break. Before osha came in and the MFG put some safely measure in they would sometimes have to run for cover. Some serious engine abuse went on at the mfg’s dyno facilities. Lol