Two 6.2s much different performance.

[Bulldogger]

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[NormB]

did a websearch for “HMMWV AND EGT”

Several useful links.

Might’ve answered a few of my questions with this article:

https://www.flashoffroad.com/Accessories/Gauges/EGT_Boost/EGT.htm

And this: https://www.steelsoldiers.com/showthread.php?170442-Max-egt-s-on-nhc250

aluminum melting point vs. performance, 1000 degrees seems to be about normal, maybe 1050.

Gonna give this a good think.

 

[Bulldogger]

I installed a non-electric Pyrometer when I turned my fuel up 1/8th. Based on what I've read for the 6.2L diesel, I keep her below 1100. My engine is tired and I have the gen 1 gearing in my drivetrain so I have to accept I'll never be fast but at least it can move a hair faster.
Bulldogger

 

[rcamacho]

Make sure you are not losing throttle movement through loose linkages/cable stretch from the foot pedal to the injection pump. Floor insulation can also limit movement. I have seen humvees that when the pedal was to the floor, the injection pump was less than 65% throttle. Also make sure the linkage from the injection pump to the trans is setup correct (cable just tight at idle). These 2 things are the first thing i look at for better performance.

My 6.2 only had about 2/3 throttle movement before adjusting the cable so I can mirror this comment


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[TOBASH]

So, reactivating this old thread with three major questions.

Regarding re-tuning to civilian specs (vs military detuning) on a 6.2 1987 engine:

1) How do we properly increase fuel at the injection pump?

2) How do we properly re-time the ip/engine?

3)How do we properly re-time the injectors?

Can a GM dealership do this? Where can we look up the proper specs for civilian use (and don't say the TM's - LOL).

Seems like this info should be around AND should be there for all us FMV owners for engine variations.

Thanks,

T

 

[Milcommoguy]

I can answer the "can a GM dealership do it" Not in my neighborhood.

Google "How do we properly" Bah bah to find out. Those are good questions with a lot of overlap on the science and technology of how diesel engines work. I would steer you to Utube. Look up some basic explanations / principles of diesel engines. We all get the high compression, fuel goes bang, down the road we go. Pretty simple on the surface with lots of engineering going into that little poof of fuel and air.

I guess where I am going with this... is it's all been worked out to play and last a long time. There are some tuning and timing adjustments requiring (another movie) diesel timing instruments, pump and injector test bench. Lots of variables, pressures, metered amounts, quality of fuel, line length, etc. Not so much just turn a screw and hold on to your seat IMO.

Everyone likes a good movie, CAMO

 

[Retiredwarhorses]

Chances of a dealership are slim, this is an ancient platform.Just google turning up a pump on a 6.2, many hits on the subject.Beware, you risk burning a hole in your pistons if done wrong.Setting the timing is done per the TM’s, but it’s as simple as just rotating the pump to advance or retardTo get the desired setting, I personally do it on sight of exhaust and sound of the motor.

 

[Retiredwarhorses]

If you have an old tired 6.2, yank it and drop in a newer serpentine GEP 6.5 setup...you have bigger injectors, large IJ Pump, redesigned combustion chamber and pre-cup chambers. These motors make for a lot more felt and useable power.

 

[TOBASH]

Steve, I think there’s gonna come a point where I am going to ask if I might send my vehicle to you or someone like you to shake it out and install a turbo engine with turbo doghouse. I’ve been thinking about it for a while. I also respect your dim view of Central tire inflation system how ever if you have one available, I will probably have you install it.

In the mean time, a small HP boost would be nice. If I need to install EGT sensors, so be it.

As always, thanks for your insight and answer.

 

[Retiredwarhorses]

Steve, I think there’s gonna come a point where I am going to ask if I might send my vehicle to you or someone like you to shake it out and install a turbo engine with turbo doghouse. I’ve been thinking about it for a while. I also respect your dim view of Central tire inflation system how ever if you have one available, I will probably have you install it.

In the mean time, a small HP boost would be nice. If I need to install EGT sensors, so be it.

As always, thanks for your insight and answer.

T
I don’t have anything ctis related...except for spindle seals and spindles.
Are you by chance on Facebook? If not, I suggest only to gain access to all the forums as well as my FB Page where I post all my builds, past, present and future.
we do a turbo upgrade every month or so....mind you, only OEM on the drivetrain, so no R4’s etc, will do aftermarket trans controller solutions as well for the 80e.

 

[TOBASH]

From what I have found on the Web:

Increase fuel flow by removing 2 bolts holding cover down on IP adjustment hex bolt, and rotate engine manually at crankshaft until adjustment hex comes into site. Then turn that hexbolt clockwise no more than 1/6 turn. If you turn more than that you will fry the engine UNLESS you have water injection, or EGT gauge to follow combustion heat.

To adjust the timing, rotate to look for smoke or listen for clacking injectors or both. Most guys say clean the injectors prior to this to make sure smoke from exhaust is real.

Anyways, that is the gospel according to The Internet.

Best,

T