Im curious as to how high can my EGT's go before its considered dangerous.

look thru here


https://www.dieselbombers.com/12-val...-safe-egt.html

aluminum starts melting at 1200*F so anything over that for extended period of time. short burts (under 4 or 5 seconds) are ok around 1400-1500 but dont keep it held at that point. if your going any higher than that at full throttle a bigger is in order

below 900 no duration, 900-1100* no more than 40 secounds, 1100-1300* 20 secounds max 1300-1600* pull out of the throttle unless on a dyno

x2

You mean my 1800* at 47psi and 99mph is too high ???

I did only hold it for ~ 3 - 4 sec past 1/4mi ( on the hiway not the strip ).

All the Cummins specs say 1250* with no time specified that I have seen. BUT what you said is VERY good advice for maximum life and performance from you engine!

Running 1250* all day would be like 3200 RPM all day... Sure it will do it... But its not good for it.

I once held the pyro at 1000 @ 2800-3200 rpm for 3 hrs,85-95 mph.That was with stock timing though.Used half litre of oil.Oh,and about 11 US mpg on that stint.I'm sure it wasn't good for it,but didn't wreck anything.

i've hit 1500* on a long hill a coupple of times towing my f150, it didn't do it any good but i don't think it hurt it too much either, cummiins says 1250* is ok so thats what i try to stay under..... if i can help it