Ok, reading thru this, EGT's came up and this has me puzzled, lol, you guys say 1100-1200 isn't really a safe limit that you can run higher? More info please.
EGT's are nothing to worry about by themselves. Combined with timing, smoke etc maybe. After you run 1550 EGT's sustained towing a hard hill one realizes that bulls#it 1200 degree EGT limits were invented by looking at the melting point of pure aluminum. Aluminum alloy in the pistons has a different melting point than pure aluminum. The EGT is largely irrelevant to pistons esp when combustion temps reach 4000 degrees. Boundry layers, carbon coating, ceramic coating, time exposed to the temps (RPM), oil temp, ECT, all play a factor into how hot the piston really gets. Further you can advance the timing or loose an injector and melt the pistons down below 1000 EGT.
You can scuff a piston from overheating the oil or run out of clearance due to temperatures. I scuffed and cracked a piston due to a radiator cap blowing off and shock cooling the block.
EGT is a measurement of how hard the engine is working, efficiency, and possible emissions reasons. It also can indicate when you are melting down the exaust wheel on the turbo.
Timing and ECT as well as oil temp have more to do with scuffing or melting a piston.
Show me one post that we melted an engine down at 1200 degrees EGT and the rebuilt engine melted down at the same EGT...
Seriously you should have seen the look on Buddy's face when I called out the 1550 EGT number and wasn't taking my foot off the throttle. The only thing I was worried about was running off the EGT gauge that only went to 1600... I regularly run 1350 with altitude changes. However I get lower EGT's with the ATT vs. the GM3. But I can add more fuel and spike em with any turbo I have tried.
Header wrap and paint have ratings from 1500 to 2000 degrees. The ATT turbo blanket starts to give up (scorch) around 1500 EGT...
In summery the EGT limit bulls#it floating around out there has done nothing but cause me unneeded worry. Mainly because I have run way over the imagined numbers for extended periods of time and given the engine every chance to melt down. The results have been funny colored paint above the exaust on the floor pan, scorched turbo blanket and that is it. I have torn down the engine and inspected the turbo - you would have no idea the EGT's I have run from looking at any of it.
