Cat 3116 max altitude questions

[Nomadic]

Thanks again for all the replies. I called Wagner Equipment in Denver, and Chris in the tech department told me the following. The 3116 has the altitude limit sticker to let you know what altitude the rack and injectors are set to operate at. At higher than max altitude the engine will be overfueled for the amount of available air in the atmosphere. He said that while you might not notice a big power difference operating at high altitude, there will be unburned fuel in the engine that could run down the sides of the cylinders into the oil and could damage components that are contacted by engine oil. He said there is also the risk of preignition with all that excess fuel sitting around which could cause piston corrosion. In addition, less air in the atmosphere means less cooling to the engine, and the engine will run hot and have hot exhaust. He said if a truck were to live at high altitude that the engine rack and injectors should be reset for the appropriate altitude, essentially cutting the fuel back to the engine. While he could not give me a quote for the job, he said it would take about an hour for his people to get to the necessary area, then another hour or so to set the rack and injectors. He said that, in all, it would be a 3-4 hour job, and if this has been done on a truck it would not necessarily be indicated by any kind of modification sticker on the engine. He said those things are documented in a report at CAT, but if there is no such report, they could use a tool to determine what altitude the truck is set to run at.

Sounds like serious consequences, not just a lack of power. If they reset the injectors and whatever to live at that altitude, driving at sea level would result in less fuel for the given oxygen level. It would be critical to understand the impact in that scenario if you are thinking about getting the truck and driving it at low elevations, even if it is just a one-time situation.

 

[pmramsey]

Its not so much about altitude above sea level as it is pressure altitude which is altitude adjusted for temperature and barometric pressure. Any hot summer day can easily cause a vehicle at 7,000 feet to deliver performance as if it was 12,000 feet. Truck turbochargers usually come with fixed waste gate systems. When the max designed turbo pressure output is reached, engine performance drops off rapidly. If one had a variable turbo waste gate system accompanied with a dash mounted turbo temperature intake gauge (T.I.T gauge) and an adjustable fuel mixture control to reduce the fuel burn to the max power output exhaust temperature, then one would be able to operate the vehicle almost any where on this planet.

 

[Floridianson]

Its not so much about altitude above sea level as it is pressure altitude which is altitude adjusted for temperature and barometric pressure. Any hot summer day can easily cause a vehicle at 7,000 feet to deliver performance as if it was 12,000 feet. Truck turbochargers usually come with fixed waste gate systems. When the max designed turbo pressure output is reached, engine performance drops off rapidly. If one had a variable turbo waste gate system accompanied with a dash mounted turbo temperature intake gauge (T.I.T gauge) and an adjustable fuel mixture control to reduce the fuel burn to the max power output exhaust temperature, then one would be able to operate the vehicle almost any where on this planet.

Guess you are a pilot and correct. But in the case of any mechanical injector engine in our older MV's would seem all we can do is if there is a altitude adjustment book then we just have to set it per specs to what alt. we plan to run at. Not what the pressure altitude is that day we want to take off / go for a drive. That is why I said a Deuce that has an easy way to turn up or down the fuel with just two wrenches and 5 mins. That and a pyrometer you could tune anytime you felt like it or engine needed it.

 

[pmramsey]

You are correct. And I might add, since I have choices, I drive an M54A1 (a 1965 with a 1975 depot rebuild) rather than an M923 or an M813.

 

[Floridianson]

Its not so much about altitude above sea level as it is pressure altitude which is altitude adjusted for temperature and barometric pressure. Any hot summer day can easily cause a vehicle at 7,000 feet to deliver performance as if it was 12,000 feet. Truck turbochargers usually come with fixed waste gate systems. When the max designed turbo pressure output is reached, engine performance drops off rapidly. If one had a variable turbo waste gate system accompanied with a dash mounted turbo temperature intake gauge (T.I.T gauge) and an adjustable fuel mixture control to reduce the fuel burn to the max power output exhaust temperature, then one would be able to operate the vehicle almost any where on this planet.

Well is that is just not just about what my 2009 Duramax has. The computer takes care of all that and I have no waste gate. My turbo vanes are computer controlled plus I have EFI live with five selections. Yea running max fuel and timing here in FL. I can bring down the EGT's buy going up on the RPM. Now when I went to Utah on #5 fuel & timing towing large trailer I could not get the EGT's down that way. I had to back down to my #1 fuel / timing setting but still down shift to bring up rpm and bring down EGT's.

 

[Awesomeness]

Thanks again for all the replies. I called Wagner Equipment in Denver, and Chris in the tech department told me the following. The 3116 has the altitude limit sticker to let you know what altitude the rack and injectors are set to operate at. At higher than max altitude the engine will be overfueled for the amount of available air in the atmosphere. He said that while you might not notice a big power difference operating at high altitude, there will be unburned fuel in the engine that could run down the sides of the cylinders into the oil and could damage components that are contacted by engine oil. He said there is also the risk of preignition with all that excess fuel sitting around which could cause piston corrosion. In addition, less air in the atmosphere means less cooling to the engine, and the engine will run hot and have hot exhaust. He said if a truck were to live at high altitude that the engine rack and injectors should be reset for the appropriate altitude, essentially cutting the fuel back to the engine. While he could not give me a quote for the job, he said it would take about an hour for his people to get to the necessary area, then another hour or so to set the rack and injectors. He said that, in all, it would be a 3-4 hour job, and if this has been done on a truck it would not necessarily be indicated by any kind of modification sticker on the engine. He said those things are documented in a report at CAT, but if there is no such report, they could use a tool to determine what altitude the truck is set to run at.

While those may be all the possibilities, I wonder how realistic or likely they are? The Army has lots of these things driving around here, and I don't think they are adjusting them for altitude. Mine works fine, and I take it up to about 10-11k.

 

[frank8003]

Frank Curiosity may have killed the cat but operating a 3116 Cat above Max. Alt without fuel change will kill the Cat even quicker. You must reduce the amount of fuel. I would guess there is a manual for how many 1000 feet you want to operate above sea level. I would also bet the way our fuel is set now the 3116 we all have are set for what the data plate states. The OP wants to operate at twice that altitude.

Holy Toledo!

 

[frank8003]

One could raise the cetain rating of the fuel used
The PDF for operation of Cat 3116 indicates that operation of it above 5000 feet is a Severe Service environmental factor

Research indicates Minimum cetane rating of 50.
Research indicates that use of 2-ethyl Hexylnitrate is good.

2-Ethyl Hexylnitrate - Google Search

www.google.com

How to Boost Cetane in Diesel

Boost the performance of your diesel engine by understanding the importance of cetane ratings. Learn how to increase cetane in diesel fuel and improve engine efficiency.

www.bellperformance.com

Does your Diesel Fuel need a Boost? | MobilityPlaza

Cetan numbers

www.petrolplaza.com

 

[Floridianson]

From what I read the 3116 is a finicky Cat. Does not like to be lugged, miss treated or chased by Dogs. I believe you are over looking the problem that is Oxygen. Oil additives or cetane booster is not going to solve that problem. Same as if we go to higher altitudes we can get sick as does the Cat.

 

[Awesomeness]

I just talked to the guys over at the CO NG depot, and they said they don't make any adjustments for altitude. They kind of looked at me stumped that I would even ask the question, haha.