I was surprised that I couldn't find any comment on this. My probe is located between #5 and 6 cylinder. Up till now I've always used 1250* for when to ease off because that's what I used on my old 2001 24v, but wondered if newer 3rd generations are different. Does anyone have any information on what Cummins thinks?

The 3rd gens can handle hotter temps. I have talked to guys who tow heavy with some mods on the 3rd gens and never see anything below 1200 all day long and not have any issues. I only have a Smarty JR on my 05 and have never seen the need to add gauges although I have thought about adding fuel supply and rail pressure gauges just for fun.When I had my 02 modded to 560 hp I would routinely see 1200-1300 the whole time I towed on hot days and never had an issue.I usually ran with the Edge comp box on level one and at that setting I was at around 475 hp.

I have been told 1350 is nothing to worry about. My 05 runs just under 800 at hwy speed. The funny thing is the more weight I add it really dont get that much hotter, but you got to watch the hills it will run up on you quick.

3rd gen's can't handle any more heat than a 2nd gen, infact the 04.5-07 piston is the easiest piston to melt of any ISB ever put in a Dodge. The cylinder temp is what we want to keep under control, on a 3rd gen the timing is VERY retarded and that puts the heat into the exhaust and the piston sees much less heat. So a 05 at 1400° will have lower cylinder temps than a 01 at 1200°. If you use 1250° as a peak on a stock 04.5-07 you are leaving a lot of power on the table. So on a STOCK 04.5-07 1450° is fine pulling grades, and some will hit 1500° which is fine for shot periods. If you have any timing then that number is reduced. A Smarty Jr on TM2 should limit sustained EGT's to 1250° and momentary peaks to 1300° when towing. When going WOT down the street I don't think the Jr will get hot enough to do damage. So.. sorry, but a 3rd gen doesn't have a blanket answer on safe EGT's but those numbers should help.

I have herad it explained several ways but that just made good sence. Thanks AH64ID

A few years ago when I was still green enough to not know how to set my own timing, I took it to a big diesel shop in rolla, MO. They had a CR block there, every piston was melted. They said it was completely stock. How can a stock engine with all of the fancy electronics allow it to melt? I think a stock 12V or even 24V (vp44) barely hit 1000. So what exactly happened to the CR engine that allows it to just melt in stock form?

The fuel doesn't atomize correctly and it more so squirts fuel onto a spot on the piston and melts holes in it. I see this almost monthly on our large mine truck engines.