I got a new Autometer pyrometer, got it installed and let it Idle for a while and the temperature went up to about 300 degrees, that looked reasonable. Today I had a job for the truck, as as i started driving I noticed the pyro reading change quickly. I thought everything would happen slowly. Well I put the truck in 3rd gear and stood on it, RPM went to over 3000 and the temperature zoomed to 1100 degrees. I backed off and the temperature immediately fell to 500 degrees. I was amazed at how fast this truck heated up. I'm still planning on installing the turbo and also plan to make at least 2 long trips loaded and pulling an enclosed trailer. Now I'm wondering if the turbo will greatly increase the egt. I've read on this forum that 1200 degrees is way too high. I'm going to throw 3 or 4 yards of dirt on the truck and connect the trailer and take some readings. My muffler shop guy says a straight exhause lowers egt readings, I have a flow master at this time.
Does anyone have an opinion?

 

Without turning the injection pump up, the turbo will lower EGT's.
1200 pre turbo or N/A isn't way too high, it's your maximum safe maintained number, lower is better, but 1200 is still safe.
I have ridden in a few trucks that had enough fuel going through them that the EGT's climbed as quick as, if not faster than the tach... LOL

Straight piping your truck will lower the EGT's, and that flow master probably isn't helping things, on my Cummins, I had a 3" Flowmaster type muffler, and an empty 60 mph cruise, straight piping it dropped EGT's 200 degrees.

 

A three inch straight exhaust will lower the EGT temps.

And the turbo can lower temps as well.
But since you can build a bigger fire in the engine, the turbo can also make the readings change faster.

A cold air intake from in front of the radiator also lowers the EGT's.

 

Those numbers sound right to me. I have headers and big exhaust, fuel turned up. With a 7000 lb load pulling big long hill (6miles worth) I would be blowing black and running near 1200- but I back off a bit to try to keep it at 1150. Also the location of the probe is right outside my #6 exhaust port.

 

My egts change very quickly as well. I have barly seen over 900* though with my turbo even with a trailer but I have not turned up fuel when I installed it. when I floor it while accelerating, It will barly put out any visible smoke. (Is your smoking like a freight train?) Just curius

 

FYI- I've had several different mufflers on my truck, including a couple different straight through mufflers, and currently a weird Walker muffler and two homemade baffles in my stacks (which are straight through, perforated core, but capped on the ends so the exhaust has to go out around the perforations at the end of the tube).

Anyway I have not noticed any significant differences in EGT between all these different setups. Maybe the sheer volume of exhaust that a single 4" pipe and then two 5" stacks can move, even with baffles and such in them, helps, I dunno.

 

Lots of neat observations, thanks. I got some experience today, I'm installing a drainfield and I was hauling 4 tons of gravel. The load did not seen to matter, what affected it most was RPM and hard acceleration at medium RPM. I've been keeping it under 900 degrees now. Here is what bothers me, there is a hill or slight grade comming out of Brownfield, Tx heading to Roswell, Nm. You can't see the grade, but my old truck loaded just keeps going slower, until I have to reach for 4th. Under that hard acceleration, I can only speculate as what my egt reading was. I've run that engine for miles in 4th at 60 mph under a hard pull. It has never given me trouble, but I'll be interested to see the readings when I go back in May. I plan to be fully loaded and pulling an enclosed trailer also loaded.
I have the 3 inch exhaust, and cool air thru the grill. I may change the muffler after i get some readings after the turbo install. My muffler guy is installing the turbo and making up a new down pipe and cross over pipe. Today when I picked up the drainfield rock, I noticed the truck weighed 8750 lbs empty.
thanks everyone

 

Smokes a little under hard acceleration, not bad, I have not messed with fuel settings. In the New Mexico Mountains it smokes like crazy and has no power, that is probably my main reason for a turbo. I was also hoping to pull small grades without downshifting, especially on interstates. This truck loaded is just plain weak.

I love this old truck, and I may just build a Dave Sponagle motor. I bought the truck about 4 years ago with a blown engine. It was a 7.3, so I bought a rebuilt engine locally. The mechanic lied to me, said it was a 7.3, but it is a 6.9. That made it even weaker by 15 HP. I do think it is a late 6.9 block, because the motor number has a 440 stamped behind it. AT least cavitation is something I won't have to worry about. I've driven this engine about 30k miles, and it runs great.

 

As far as pulling power goes with these engines, the key is to keep the rpm up before it starts bogging down. That should be easy enough with a standard tranny. Mine is E4OD, so is a bit tricky. If I am heading into a long hill I punch out the OD, then if it gets loaded up kick the pedal down and will drop into 2nd. (This is where its important to have that old FILP set right lol). Ya, you aren't going fast, but as long as you can keep the rpm above 2400 it seams to keep on pulling. Also I have 3.55 rear end, if you are running a lower ratio that will slow it down more, but should also help with the power issue.