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Torque rating

Oxyacetylene

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Well all be!


I would think the MTV would be north of 800 lb ft for the tow rating it has but who knows, I ll get my engine ID and call Empire CAT and see if they can run the number


on a side note,

who has reflashed their LMTV to MTV specs and what did the dealer charge you for the flash
Wehring has an M1078A1, and had a 330HP flash installed by a CAT mechanic/tech. It's in his mods thread:
http://www.steelsoldiers.com/showthread.php?131893-Wehring-LMTV-Mods
You also asked about torque specs for the M1078(A0). If you have the A0 variant, it's mechanical injection, no engine computer.
 

BigMontana

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Too many acronyms for me, but are you asking about fiddling with engine management computer to make more horsepower? I have seen that done by various tuners for sports cars. I did not think that was even possible with these low tech diesels. Is it?
Hmmm, my trucks appear to have a cat data port on them in the cab would that say one way or the other?
No, if you have the 94 the computer stuff is sensors and such, most of your fuel injection is done by cam rockers depressing pre charged fuel injectors. Hypothetically you should be able to have a 100% electrical system malfunction while the truck is running and you might not even notice in the performance of the truck...hypothetically.
 

BigMontana

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Well all be!


I would think the MTV would be north of 800 lb ft for the tow rating it has but who knows, I ll get my engine ID and call Empire CAT and see if they can run the number


on a side note,

who has reflashed their LMTV to MTV specs and what did the dealer charge you for the flash
The 225 HP 3116 MUI engine that is in the 1994 puts out 520 ft./lbs.

I too have been having difficulty finding the torque numbers, but I suspect the OP asked because they care about their engine longevity but would like "a little more torque" So for the OP and a few others in the same boat: you should have plenty of "safe" space left to add a little power, the engine has been known to still be in factory range and reliable at 735 ft/lb.

When upgrading the engine for more torque: heat management will be essential--when climbing hills at full or near full throttle pay attention to your water temps, there are probably a few easy mods that can be made to increase cooling efficiency on the cheap eg. since you don't expect the engine to be taking potential small arms fire. small holes in the front skid plate like a bunch of really small ones, yeah sure it'll take a few hours to drill, and don't drill too many and compromise the integrity of the skid plate, but think holes that are about half the size of the gap between the skid plate and radiator so you aren't shoving rocks in that won't eventually fall out, everything else should wash out with a hose after a decent day of mud operations.

This thread was painful to read...a lot of non answers wrapped around unnecessary ego, be better to one another.
 
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BigMontana

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Too many acronyms for me, but are you asking about fiddling with engine management computer to make more horsepower? I have seen that done by various tuners for sports cars. I did not think that was even possible with these low tech diesels. Is it?
Not only is it possible, it's possible very cheaply, there's a few internal engine screws that let you play with the mix.
Supposedly the turbo wastegate is really easy to tighten up.

A waste gate is the thing when the turbo hits a certain PSI of air pressure in the intake it just blows the extra air out the bottom instead of into the intake. I'm told but have not confirmed that cutting a wastegate line and cap'ing it off will give a few more psi of boost, if you did that simultaneous to richening up the mix a bit you'd be pretty safe overall.
 

Ronmar

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I think the 225@2600 RPM engine is 620 ft/lb@1550 RPM, this from an eaton clutch spec catalog, as i have never been able to find the cat highway engine specs for this or the 290HP. Closest I find for the 290 is a spec from that same eaton catalog, for a 300HP@2600 RPM 3116 which is 720ft/lb, so I am estimating 710-715 ft/lb for the 290hp tune used in the A0 MTV.

Tuning isnt that easy on a mechanical. To change boost pressure you need to put in a gate actuator with a different spring rating.

They used different turbos and governors in the 225 and the 290 for a reason, as the governor is mechanically matched to the turbos pressure-flow curve. Because of this it is very easy to upset that relationship If you alter knowns like turbo pressure, or adj how the governor responds to manifold pressure feedback. IMO the only consistent way to turn a 225 into a 290 is to replace the governor and turbo with ones from a 290 and adjust the top end/rack to the 290 fuel spec and inj timing...
 

BigMontana

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I think the 225@2600 RPM engine is 620 ft/lb@1550 RPM, this from an eaton clutch spec catalog, as i have never been able to find the cat highway engine specs for this or the 290HP. Closest I find for the 290 is a spec from that same eaton catalog, for a 300HP@2600 RPM 3116 which is 720ft/lb, so I am estimating 710-715 ft/lb for the 290hp tune used in the A0 MTV.

Tuning isnt that easy on a mechanical. To change boost pressure you need to put in a gate actuator with a different spring rating.

They used different turbos and governors in the 225 and the 290 for a reason, as the governor is mechanically matched to the turbos pressure-flow curve. Because of this it is very easy to upset that relationship If you alter knowns like turbo pressure, or adj how the governor responds to manifold pressure feedback. IMO the only consistent way to turn a 225 into a 290 is to replace the governor and turbo with ones from a 290 and adjust the top end/rack to the 290 fuel spec and inj timing...
Exceptionally helpful reply. Thank you. You sound like you've dug around in these engines.

Here is the video I saw this stuff on, is this guy just full of crap, or taking unreasonable chances with his engine? or what's your opinion?


From my limited knowledge, I've had mechanics (illegally) turn my fuel screws on old oilfield trucks that mostly run off-road, I thought on a diesel you just turn it up until you're visibly blowing smoke at cruise and then back off about 25% of the change from stock, so that just means richer -- and richer means cooler running and higher torque, I don't think it results in a lot of change re temp or torque, but I figure the cooler running makes up for the abuse of higher torque. (not that -- say 240 HP is abuse of a 1993 3116 in any way, but you get the idea).

I was actually considering sometimes down the road doing a super light dry propane injection, like something I could run 8 hours before it was dry on a 20 lb tank. I understand propane at light injection levels to have a synergistic effect with diesel especially where you might have already been running a hair rich.

Propane has a completely different mechanism of action from NOS, which is an oxidizer--
Propane makes the diesel burn more completely and also lowers the EGT a hair, supposedly (and this is the only part I am actually sure of): a little bit of propane also reduces overall greenhouse gas emissions by a lot--theres some pretty good research on that effect in diesel generators because of the more efficient use of fuel.
 

coachgeo

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Exceptionally helpful reply. Thank you. You sound like you've dug around in these engines.

Here is the video I saw this stuff on, is this guy just full of crap, or taking unreasonable chances with his engine? or what's your opinion?

Wes (a member here.... and founder of the yellow parts spread sheet at top of this forum.... who did the video you linked) is a pretty well regarded member here. He knows the practical man's backyard; keep it running and working, surgery and maintenance of the 3116 better than most anyone.
 

Ronmar

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And i laugh every time I see that:) is that engine still even running? Of course they never seem to report back on any failures...

What happens when you deliver too much fuel? In diesels, particularly at lower loads, is that fuel builds up on the cylinder walls and washes down past the rings to dilute the engine oil. This can lead to things like crankcase explosions, and it interferes with how the rings are lubricated Increasing cylinder wear. This is why diesels are happier at higher op temps. The same thing can happen with gas engines. That adjustment increases fuel delivery across the entire spectrum. What was it again, 1-2 turns or 3-4?

cutting the line to the wastegate actuator removes its ability to regulate pressure, and the turbo will run at its peak pressure. But how much actual air volume does that add? How does the governor know how far to move the rack as the peak pressure it now sees has no corresponding rack point because it was never intended to ever see it…

for best efficiency you want the right amount of fuel mixed with the volume of air, so it combusts completely and doesn't condense on the cylinders, or so that it doesn't continue to burn into the exhaust stroke and out into the exhaust and cook the valves guide seals and turbo..

Cat spent literally millions of dollars building and testing this series of mechanically governed engines, developing multiple governor configurations for many customers/markets That would survive long hours of use.

if you think you can do better than cat in your yard with a turn here and a crimp there, knock yourself out, its your wallet… but I think you may find the experience is ultimately less than satisfying… having tuned and more importantly FAILED to properly tune a few power systems over the years, until I see the dyno and egt plots and as I get older the longevity proof(because I would rather drive them than have to keep fixing them), they are literally blowing smoke…

it surely doesn't make sense to me to take the risk when there are cat tested and proven parts that can get you to a higher tune…

YMMV, good luck…
 

BigMontana

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And i laugh every time I see that:) is that engine still even running? Of course they never seem to report back on any failures...

What happens when you deliver too much fuel? In diesels, particularly at lower loads, is that fuel builds up on the cylinder walls and washes down past the rings to dilute the engine oil. This can lead to things like crankcase explosions, and it interferes with how the rings are lubricated Increasing cylinder wear. This is why diesels are happier at higher op temps. The same thing can happen with gas engines. That adjustment increases fuel delivery across the entire spectrum. What was it again, 1-2 turns or 3-4?

cutting the line to the wastegate actuator removes its ability to regulate pressure, and the turbo will run at its peak pressure. But how much actual air volume does that add? How does the governor know how far to move the rack as the peak pressure it now sees has no corresponding rack point because it was never intended to ever see it…

for best efficiency you want the right amount of fuel mixed with the volume of air, so it combusts completely and doesn't condense on the cylinders, or so that it doesn't continue to burn into the exhaust stroke and out into the exhaust and cook the valves guide seals and turbo..

Cat spent literally millions of dollars building and testing this series of mechanically governed engines, developing multiple governor configurations for many customers/markets That would survive long hours of use.

if you think you can do better than cat in your yard with a turn here and a crimp there, knock yourself out, its your wallet… but I think you may find the experience is ultimately less than satisfying… having tuned and more importantly FAILED to properly tune a few power systems over the years, until I see the dyno and egt plots and as I get older the longevity proof(because I would rather drive them than have to keep fixing them), they are literally blowing smoke…

it surely doesn't make sense to me to take the risk when there are cat tested and proven parts that can get you to a higher tune…

YMMV, good luck…
Umm...you do know the fuel air mixes on a factory cat is essentially set by the EPA? That not the optimum running conditions for a diesel. That's why it's illegal to do those mods, unless you're using it off road only.

The optimum 3116 thermostat is 195 degrees

It's all interesting to think about, but I think Wes is probably right.

Most of the logging, mining and firefighting crews I know fix their own diesels, and flee from cat mechanics, because a cat mechanic at a cat shop is putting 2x cost parts on for 1.5x the labor cost. And a lot of folx are paying way too much for parts that match a military number where they are the exact same as a NAPA/O'riely part...so I am super thankful for Wes's spreadsheet.


Although maybe keeping an eye on the oil analytics after doing the mix screw is a good idea. The mechanic I talked to today said just avoid lugging the engine after you turn it up...that sounds like it might be the answer to the fuel getting past the rings issue Ronmar mentions, but still--
When I do the fuel screw someday down the road
I'll use my oil analytics though, see how stuff looks.
 
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Ronmar

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Yea, good luck getting your A0 to operate at 195 unless it is really warm out, as they had cat alter the cooling system for the A0, and not in a good way to maintain a steady temp(Youtube user Rronmar, i have a video there of the changes I have made to get a stable op temp)

All manufacturers have EPA regs they must follow. You do know these are AGricultural engines right? to meet those EPA regs(and there were not a lot for off-road diesels in the 90’s), you must be near the ideal a/f ratios and burn quality anyway. Just about anything you will do to them in your front yard with hand tools is likley to cause issues somewhere in their operating range. To do it properly you would have to recreate parts for the governor, and have some way to measure wether those changes are effective(back to the millions they spent in R&D). Mechanically governed diesel is really a lost art. Thats why HEUI was such a leap for the designers. You could completely alter the characteristics of an engine in a few minutes with a laptop, and of course the dyno and instrumentation to confirm your results. Then you could simply flash that tune into any other engines ECU…

like I said, its your wallet and time…
 
Last edited:

BigMontana

Member
58
50
18
Location
Polson, MT
And i laugh every time I see that:) is that engine still even running? Of course they never seem to report back on any failures...

What happens when you deliver too much fuel? In diesels, particularly at lower loads, is that fuel builds up on the cylinder walls and washes down past the rings to dilute the engine oil. This can lead to things like crankcase explosions, and it interferes with how the rings are lubricated Increasing cylinder wear. This is why diesels are happier at higher op temps. The same thing can happen with gas engines. That adjustment increases fuel delivery across the entire spectrum. What was it again, 1-2 turns or 3-4?

cutting the line to the wastegate actuator removes its ability to regulate pressure, and the turbo will run at its peak pressure. But how much actual air volume does that add? How does the governor know how far to move the rack as the peak pressure it now sees has no corresponding rack point because it was never intended to ever see it…

for best efficiency you want the right amount of fuel mixed with the volume of air, so it combusts completely and doesn't condense on the cylinders, or so that it doesn't continue to burn into the exhaust stroke and out into the exhaust and cook the valves guide seals and turbo..

Cat spent literally millions of dollars building and testing this series of mechanically governed engines, developing multiple governor configurations for many customers/markets That would survive long hours of use.

if you think you can do better than cat in your yard with a turn here and a crimp there, knock yourself out, its your wallet… but I think you may find the experience is ultimately less than satisfying… having tuned and more importantly FAILED to properly tune a few power systems over the years, until I see the dyno and egt plots and as I get older the longevity proof(because I would rather drive them than have to keep fixing them), they are literally blowing smoke…

it surely doesn't make sense to me to take the risk when there are cat tested and proven parts that can get you to a higher tune…

YMMV, good luck…
I'm sorry I stopped reading at "they didn't have a lot of off road diesels in the 1990s
Yea, good luck getting your A0 to operate at 195 unless it is really warm out, as they had cat alter the cooling system for the A0, and not in a good way to maintain a steady temp(Youtube user Rronmar, i have a video there of the changes I have made to get a stable op temp)

All manufacturers have EPA regs they must follow. You do know these are AGricultural engines right? to meet those EPA regs(and there were not a lot for off-road diesels in the 90’s), you must be near the ideal a/f ratios and burn quality anyway. Just about anything you will do to them in your front yard with hand tools is likley to cause issues somewhere in their operating range. To do it properly you would have to recreate parts for the governor, and have some way to measure wether those changes are effective(back to the millions they spent in R&D). Mechanically governed diesel is really a lost art. Thats why HEUI was such a leap for the designers. You could completely alter the characteristics of an engine in a few minutes with a laptop, and of course the dyno and instrumentation to confirm your results. Then you could simply flash that tune into any other engines ECU…

like I said, its your wallet and time…

Okay, go out to your truck and find the "meets California Emissions sandards for on road use" metal plate on the top of your engine. Yes the engine is used in agricultural and marine applications, this is the on road version otherwise I wouldn't/shouldn't be able to register it.

i found your channel and your description of the TPS is useful. It's exactly the same as those speed controllers we used to use in our R/C cars...simple, reliable, and a waste of battery power when running an RC car ... Not a problem with a big engine though. I'm gonna send that vid to my dad, an electrical engineer and we'll have a chat about this stuff when I get home.

i think you might have some erroneous data about how fuel air ratios work in regard to cleanliness vs operational efficiency. I've been tuning nitromethane engines and gasoline racing engines for about 25 years now. I have a cammed Indian motorcycle that lets me adjust between track and road, and gives me a fuel air mix reading at all times, however, I only know diesels from hanging around the shop while the mechanics fixed my heavy haul big rigs. With a gas engine I'd just read the plugs, I'm not sure how to do a diesel except by finding the smoke point.


I'm 90% sure you're giving cat engineers credit for achieving a goal they were not attempting to achieve.

You might ought to Google the difference between the fuel air mixtures that make up: (1) stoichiometric, (2) minimum emissions, (2) max torque, and (3) max cruise efficiency...they're all different numbers...you write like you don't know that basic information.
 

GeneralDisorder

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Hypothetically you should be able to have a 100% electrical system malfunction while the truck is running and you might not even notice in the performance of the truck...hypothetically.
Transmission is computer controlled. You will absolutely notice 100% electrical failure as it will result in the truck not moving at all. Your truck will turn into a very heavy air compressor.

This goes back to the age old false argument about the A1+ trucks being less reliable because "OH NO! ITS HAS COMPUTERZ!!@$#@!" - the reality is quite the opposite. My truck has more power, more torque, and a MORE reliable transmission control (a weak point on the A0's actually). And I carry spares for every electronic component.

The military engines have no emissions equipment or regulations. They don't care. My C7 has the M-ATV map from Caterpillar and is 370 HP, 931 TQ. Oshkosh is STILL putting the C7 into brand new A1P2's to this very day. They have the same "emissions" as they had in 2010 before Cat pulled out of the over-the-road market. No DEF, no EGR, no DPF, etc. NOTHING. Any resemblance to on-road engines or certifications they may have is purely coincidental - the military didn't ask for it and doesn't care one bit about it.

Your ability to register the truck is purely luck and coincidence. If you were able to purchase an A1P2 (you can't because they don't sell armor) you would have 2010 era emissions engine installed into a "truck" built anywhere up to 2023. My local reserve unit has an A1P2 with a June 2021 build date....... same C7 that's in my 2008.
 
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Ronmar

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I'm sorry I stopped reading at "they didn't have a lot of off road diesels in the 1990s



Okay, go out to your truck and find the "meets California Emissions sandards for on road use" metal plate on the top of your engine. Yes the engine is used in agricultural and marine applications, this is the on road version otherwise I wouldn't/shouldn't be able to register it.

i found your channel and your description of the TPS is useful. It's exactly the same as those speed controllers we used to use in our R/C cars...simple, reliable, and a waste of battery power when running an RC car ... Not a problem with a big engine though. I'm gonna send that vid to my dad, an electrical engineer and we'll have a chat about this stuff when I get home.

i think you might have some erroneous data about how fuel air ratios work in regard to cleanliness vs operational efficiency. I've been tuning nitromethane engines and gasoline racing engines for about 25 years now. I have a cammed Indian motorcycle that lets me adjust between track and road, and gives me a fuel air mix reading at all times, however, I only know diesels from hanging around the shop while the mechanics fixed my heavy haul big rigs. With a gas engine I'd just read the plugs, I'm not sure how to do a diesel except by finding the smoke point.


I'm 90% sure you're giving cat engineers credit for achieving a goal they were not attempting to achieve.

You might ought to Google the difference between the fuel air mixtures that make up: (1) stoichiometric, (2) minimum emissions, (2) max torque, and (3) max cruise efficiency...they're all different numbers...you write like you don't know that basic information.
Well if you already know all this why are you bothering to ask these questions...

You do realize what happens to engine manufacturers whos engines fail to meet performance and longevity goals right? Expensive recalls and class action lawsuits. Which is why they actually proof them with something other than the seat of their pants.

i will certainly give credit where credit is due, they made an engine that has survived and is still in service all over the world in large quantities...

Like i said, your engine, your wallet and time, crank that sucker up and let er buck...
 
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BigMontana

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Well if you already know all this why are you bothering to ask these questions...

You do realize what happens to engine manufacturers whos engines fail to meet performance and longevity goals right? Expensive recalls and class action lawsuits. Which is why they actually proof them with something other than the seat of their pants.

i will certainly give credit where credit is due, they made an engine that has survived and is still in service all over the world in large quantities...

Like i said, your engine, your wallet and time, crank that sucker up and let er buck...
Most people know something, you just have to sort out all the ego. I learned two things from you that will help me down the road.
 
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BigMontana

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I believe you re the emissions thing, but my engine has a plate on top that specifically says it's EPA emissions compliant...do you think this means it's not the original engine?

Also, if the A2 has a better transmission controller, but the same trans is it an easy upgrade?

Transmission is computer controlled. You will absolutely notice 100% electrical failure as it will result in the truck not moving at all. Your truck will turn into a very heavy air compressor.

This goes back to the age old false argument about the A1+ trucks being less reliable because "OH NO! ITS HAS COMPUTERZ!!@$#@!" - the reality is quite the opposite. My truck has more power, more torque, and a MORE reliable transmission control (a weak point on the A0's actually). And I carry spares for every electronic component.

The military engines have no emissions equipment or regulations. They don't care. My C7 has the M-ATV map from Caterpillar and is 370 HP, 931 TQ. Oshkosh is STILL putting the C7 into brand new A1P2's to this very day. They have the same "emissions" as they had in 2010 before Cat pulled out of the over-the-road market. No DEF, no EGR, no DPF, etc. NOTHING. Any resemblance to on-road engines or certifications they may have is purely coincidental - the military didn't ask for it and doesn't care one bit about it.

Your ability to register the truck is purely luck and coincidence. If you were able to purchase an A1P2 (you can't because they don't sell armor) you would have 2010 era emissions engine installed into a "truck" built anywhere up to 2023. My local reserve unit has an A1P2 with a June 2021 build date....... same C7 that's in my 2008.
 

coachgeo

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I believe you re the emissions thing, but my engine has a plate on top that specifically says it's EPA emissions compliant...do you think this means it's not the original engine?

Also, if the A2 has a better transmission controller, but the same trans is it an easy upgrade?
Do you have an A0 or A1? No A2 exist in public hands. Only difference between A0 and A1 is one bearing/bushing change.... and it got different Transmission Control Unit, (TCU) along with different keypad, matching wire harness and sensors. The Elecrical/TCU changes are only cause trans needed to work in pair with an Engine that has an ECU. The A0 CAT 3116 has no ECU.. it's a mechanical timed/injected engine. All the trucks above the A0 have an ECU.
 
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BigMontana

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Mine is a 1994, so I reckon it's an A0
I know my engine is mechanical fuel injected engine with a lifter pump run off the voltage from one of those variable resistor wiper things.

Do you have an A0 or A1? No A2 exist in public hands. Only difference between A0 and A1 is one bearing/bushing change.... and it got different Transmission Control Unit, (TCU) along with different keypad, matching wire harness and sensors. The Elecrical/TCU changes are only cause trans needed to work in pair with an Engine that has an ECU. The A0 CAT 3116 has no ECU.. it's a mechanical timed/injected engine. All the trucks above the A0 have an ECU.
 
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