Don T

I run my 95 Ram 12 valve pulling my 10500 lb camper and pull a dump trailer . I installed a 10 torque plats . I marked and installed the plate in the place where the stock torque plate sat. I have install a 3000 rpm governor spring also. I can see 1000 deg in the exhaust manifold in the thick part from the head out. I looking at installing spray pattern injectors with 6 holes and 50 hp over the stock injector. I think a fine spray show work better for timing . How hot can I run this 12 V on the pryro before I will burn it up. I hope I gave out info that some one can help me out. Running 322 HP and 645 T now.

Sea:\>Drive

Most try to keep it under 1600 for any prolonged period of time. Cummins says 1600 all day long I believe. Many run hotter but only for very short periods (drag racing or sled pulling).

oliver foster

I think Cummins specs 1300* all day long.

Pistons melt at 1350* if they are exposed to it long enough, IIRC.

I would say 1600* would be okay for very short time frames.
Like sticking you hand in the 450* oven to grab a slice of pizza, no harm done if your quick.
Hang out there too long, and it feels like burning

patdaly

Everything I have ever read was 1250F pre-turbo to be safe.

I tend to be a little more concerned with keeping it together than wringing the last little bit of performance out though.

If you are running that high for long periods, it is time to figure out how to get her more air.

nascar mark

Pat is correct. 1250 degs all day long and 1300 for a minute....anything temp wise over that, is best to keep it under 15 sec

KATOOM

To be completely accurate, Cummins states that the 5.9 can withstand 1350* EGT's all day long WHILE being monitored by multimillion dollar equipment. But that said how much do you trust your $100 pyrometer.....or do you think its anywhere as accurate as what Cummins uses on their dyno? I trust my ISSPRO but I dont think its 100% accurate either. Aluminum begins to melt around 1250* but pistons are not made of plain aluminum but rather a recipe of aluminum and other more heat tolerant materials.

If you're pulling a long grade then the 50* difference between 1300* and 1350* could be disastrous. And.....nothing is more damaging to an engine than excessive heat. So.....since most diesels use the same type of piston material, this is why you see the general rule of thumb being that 1250* is the highest "sustained" running EGT's you want to run and a few seconds hotter is OK. That gives around a 100* window of inaccuracy error for the average pyro. Personally I never let my EGT's get above 1300* since I believe thats just too darned hot for my motor.

nascar mark

Not to start a pissing match but, to be completely accurate, Cummins states 1250 deg's for prolonged periods on the 2nd gen in question. You can't blanket all 5.9's together..... This is direct from Cummins North West and Piers is the one that asked them back in the day. I used to contract my services to PDR and Piers since 2001 to 2012 running the shop, sales and then becoming the manager of the business, before starting my own diesel parts store and know a few things about the cummins. I have helped build Big Bad Dodges engine, Fletchers engine, Jet Pilots engine and Maddogs engine among many others, so we have a pretty good relationship with Cummins over the years and don't believe they would steer us wrong on the temperatures.

KATOOM

No pissing match here..... I always appreciate new info and new sources. I always generally agree that your said EGT's are the normal and safest temps but years ago I read from a reliable source regards Cummins stating 1350* for the ISB. I kinda dislike saying it though as it lets people think that they can safely run EGT's like that. Just for sake of curiosity I'll see if I can find where I read that.....