5.9 Fuel Economy Rebuild
#1
5.9 Fuel Economy Rebuild
So, I'm a new member and what better way to introduce myself than by starting a thread with such a laughable title, right?
Background: I got a new '98 Ram 5.9 back in 1998. I drove it until 2008 when the heater core blew and drained all my coolant, causing the engine to overheat. I filled the radiator with water, but like an idiot didn't wait for the engine to cool down before starting it back up which circulated the cool water through the glowing hot heads and they both immediately cracked. I purchased new OE heads from King but didn't have the expertise to install them and didn't have the money to have it done, so in the back yard it sat until now. I now have the expertise (from working on vehicles with my dad the last few years) and a little money, so let's get this truck back on the road!
Here's what I've done so far: I borrowed an engine crane, and disconnected or removed everything necessary to pull the engine. This week, I'll pull it, strip it down and send the block off to be magnafluxed, decked, and over-bored .030 (it has major scoring in one cylinder from a cracked ring). Since the engine has to be rebuilt anyway, why not rebuild it for optimum mpg? Yes, it's a gas guzzling 5.9, but there is LOTS of room for improvement. I do not want to mod it in any way that causes me to lose torque or hp, so I'm only interested in mods that make gains through efficiency improvement (which have the added benefit of making extra power available if you choose to use it). So. . . Here's the plan for the immediate future:
Hypereutectic pistons and gapless top rings raising compression to 10.5:1
Programmer
Port and polish my own heads (without increasing passage volume)
Plenum fix and kegger mod with volume reduction
Port match (not gasket match) heads and intake manifold
Old school style open air filter (big circular filter atop throttle body)
Cat delete (it's probably clogged anyway) and O2 senser mod
Lowest recommended viscosity oils in everything and go full synthetic
E3 spark plugs
Later, as money allows:
Locking hubs (to decrease rolling resistance on my 4x4)
Electric fan conversion
Electric water pump conversion
Long tube tri-y headers
Header back exhaust
High flow muffler
Fastback tonneau cover (roof to tailgate slant)
Full underbody panels
Any thoughts, questions, or input is most welcome!
-Michael
Background: I got a new '98 Ram 5.9 back in 1998. I drove it until 2008 when the heater core blew and drained all my coolant, causing the engine to overheat. I filled the radiator with water, but like an idiot didn't wait for the engine to cool down before starting it back up which circulated the cool water through the glowing hot heads and they both immediately cracked. I purchased new OE heads from King but didn't have the expertise to install them and didn't have the money to have it done, so in the back yard it sat until now. I now have the expertise (from working on vehicles with my dad the last few years) and a little money, so let's get this truck back on the road!
Here's what I've done so far: I borrowed an engine crane, and disconnected or removed everything necessary to pull the engine. This week, I'll pull it, strip it down and send the block off to be magnafluxed, decked, and over-bored .030 (it has major scoring in one cylinder from a cracked ring). Since the engine has to be rebuilt anyway, why not rebuild it for optimum mpg? Yes, it's a gas guzzling 5.9, but there is LOTS of room for improvement. I do not want to mod it in any way that causes me to lose torque or hp, so I'm only interested in mods that make gains through efficiency improvement (which have the added benefit of making extra power available if you choose to use it). So. . . Here's the plan for the immediate future:
Hypereutectic pistons and gapless top rings raising compression to 10.5:1
Programmer
Port and polish my own heads (without increasing passage volume)
Plenum fix and kegger mod with volume reduction
Port match (not gasket match) heads and intake manifold
Old school style open air filter (big circular filter atop throttle body)
Cat delete (it's probably clogged anyway) and O2 senser mod
Lowest recommended viscosity oils in everything and go full synthetic
E3 spark plugs
Later, as money allows:
Locking hubs (to decrease rolling resistance on my 4x4)
Electric fan conversion
Electric water pump conversion
Long tube tri-y headers
Header back exhaust
High flow muffler
Fastback tonneau cover (roof to tailgate slant)
Full underbody panels
Any thoughts, questions, or input is most welcome!
-Michael
Last edited by Big Green 360; 10-28-2013 at 03:38 AM.
#2
A cat delete may or may not benefit you, I see your planning on doing the spark plug non fouler trick. An aftermarket cat is an option. I would like to see how those E3 plugs do for you. Generally they don't seem to do a lot in these trucks. As for the tonneau cover, there is an ongoing debate if that helps or hurts mileage. I have never seen a "roof to tailgate" slant. Also I don't think this thread is in the right place, someone will probably come along and move it.
#3
You will more than likely be able to get a bit more power with what you have in mind, but, don't expect gas mileage to change much.
The locking front hubs really isn't going to net you much in the way of fuel economy either. Looking at it from a cost/benefit angle, there are better ways to spend your money. Although, not having the unit bearings up front is always nice.... reduced maintenance costs will pay for that mod before fuel savings will. (LONG before.)
Can you even FIND tri-y headers any more? I had a hard time even finding long tubes for these trucks. Seems Pacesetter is the only one that still makes them. Used to be a place around here that custom made headers. But, they have long since gone the way of the dodo.
Open element may not be the best either. The stock system at least pretends to draw colder air from the fender area. The open element will be getting that nice, toasty warm, under hood air......
Skinny, street-tread tires will help. (and small diameter as well, or, taller gears.)
The locking front hubs really isn't going to net you much in the way of fuel economy either. Looking at it from a cost/benefit angle, there are better ways to spend your money. Although, not having the unit bearings up front is always nice.... reduced maintenance costs will pay for that mod before fuel savings will. (LONG before.)
Can you even FIND tri-y headers any more? I had a hard time even finding long tubes for these trucks. Seems Pacesetter is the only one that still makes them. Used to be a place around here that custom made headers. But, they have long since gone the way of the dodo.
Open element may not be the best either. The stock system at least pretends to draw colder air from the fender area. The open element will be getting that nice, toasty warm, under hood air......
Skinny, street-tread tires will help. (and small diameter as well, or, taller gears.)
#5
You're driving vehicle with a curb weight of 4,640lbs and 5.9L of displacement. You're spending time and money (time is also money) in an attempts to re-engineer what professionals have done all in an attempts to eek out *maybe* an mile or two per gallon of gas consumed.
Overall, what's to be gained?
Have you considered how much driving you will have to complete before you break even on the above mentioned investment?
To say your vehicle is a "gas guzzler" is simply not true. Compare your truck to a truck built in the mid-1970s and you'll see a true gas guzzler that was lucky to achieve 8mpg.
Are you an "air hauler"? An air hauler is someone who drives a pickup for day-to-day activities without anything in the cargo box. If you are, and you're complaining about the "poor" gas mileage of your vehicle, then now is a good time to re-examine your priorities and needs.
A pickup truck is a great vehicle for certain individuals to own; however, spending a lot of money all in the name of saving a nickel on fuel expenses is fool hardy. My suggestion to people who are always looking to get better gas mileage out of their pickup is to do what I've done, which is to buy a good, used 4-banger as my daily driver. My Mazda 3 hatchback achieves fantastic highway mileage and has a large enough interior for some basic hauling needs; however, there is no way that little car can haul 8 sheets of drywall, 10 sheets of 7/16" OSB, and a myriad of other supplies I need for a current remodeling project at my house. It also cannot efficiently or effectively tow a 10" trailer that is loaded down with tools and parts to be hauled to a vintage Volkswagen swap meet. Conversely, every pickup I have owned has not been an efficient vehicle for in-town driving, parking, or other minor travels.
Some of the work you've listed (porting the heads) can yield fantastic benefits for the needs of the truck; however, exercise caution by blindly spending money in a pursuit of a Holy Grail of fuel economy. Chances are the stock heads and other internals may need to be replaced since OEM quality has known issues. I did some minor tweaks on my old Second Gen that resulted in both gains in fuel economy and improved torque. Then again, my goal was torque because I use a truck for its intended purpose -- hauling cargo.
Just some food for thought.
Overall, what's to be gained?
Have you considered how much driving you will have to complete before you break even on the above mentioned investment?
To say your vehicle is a "gas guzzler" is simply not true. Compare your truck to a truck built in the mid-1970s and you'll see a true gas guzzler that was lucky to achieve 8mpg.
Are you an "air hauler"? An air hauler is someone who drives a pickup for day-to-day activities without anything in the cargo box. If you are, and you're complaining about the "poor" gas mileage of your vehicle, then now is a good time to re-examine your priorities and needs.
A pickup truck is a great vehicle for certain individuals to own; however, spending a lot of money all in the name of saving a nickel on fuel expenses is fool hardy. My suggestion to people who are always looking to get better gas mileage out of their pickup is to do what I've done, which is to buy a good, used 4-banger as my daily driver. My Mazda 3 hatchback achieves fantastic highway mileage and has a large enough interior for some basic hauling needs; however, there is no way that little car can haul 8 sheets of drywall, 10 sheets of 7/16" OSB, and a myriad of other supplies I need for a current remodeling project at my house. It also cannot efficiently or effectively tow a 10" trailer that is loaded down with tools and parts to be hauled to a vintage Volkswagen swap meet. Conversely, every pickup I have owned has not been an efficient vehicle for in-town driving, parking, or other minor travels.
Some of the work you've listed (porting the heads) can yield fantastic benefits for the needs of the truck; however, exercise caution by blindly spending money in a pursuit of a Holy Grail of fuel economy. Chances are the stock heads and other internals may need to be replaced since OEM quality has known issues. I did some minor tweaks on my old Second Gen that resulted in both gains in fuel economy and improved torque. Then again, my goal was torque because I use a truck for its intended purpose -- hauling cargo.
Just some food for thought.
#6
Some good ideas you have and they will improve your mpg a little, but don't expect to gain all your money back in parts and labour in mpg savings. Make the motor breath better and it will increase your power and your mpg,
Yes the part time kit will help, I know it will as I drove around with no front axle shafts in the front end for two months and saw a increase abit 2-5 mpg.
As for headers in a tri Y look for a set of Doug Thorley for a Dakota 5.2 or 5.9 they fit our truck, next best bet is a mid length header from Spin tech, neither are cheap over $600 for the set.
Next ditch the kegger all together and find an Mopar M1 or the an F1 intake manifold. The M1 is out of production but if you look around had you can find them.
1.7 RR's or a RV cam will also help with your mpg
Ditching the cat will help, so will removing the A/C pump.
Good luck with your build and keep us informed as to how you make out with it.
Yes the part time kit will help, I know it will as I drove around with no front axle shafts in the front end for two months and saw a increase abit 2-5 mpg.
As for headers in a tri Y look for a set of Doug Thorley for a Dakota 5.2 or 5.9 they fit our truck, next best bet is a mid length header from Spin tech, neither are cheap over $600 for the set.
Next ditch the kegger all together and find an Mopar M1 or the an F1 intake manifold. The M1 is out of production but if you look around had you can find them.
1.7 RR's or a RV cam will also help with your mpg
Ditching the cat will help, so will removing the A/C pump.
Good luck with your build and keep us informed as to how you make out with it.
#7
I was gonna say removing the A/C is a must if you want economy.
Personally, for the time/money involved you could just buy a little Honda or something.
I spent $850 and got a little 1980s Honda motorcycle.
Otherwise you might get a little bit better gas mileage, but not really worth the time/effort IMO.
I mean, it's a big *** truck dude, you aren't going to get that great of fuel economy.
Personally, for the time/money involved you could just buy a little Honda or something.
I spent $850 and got a little 1980s Honda motorcycle.
Otherwise you might get a little bit better gas mileage, but not really worth the time/effort IMO.
I mean, it's a big *** truck dude, you aren't going to get that great of fuel economy.
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#8
Love the input! Based on the responses, I should probably clarify my goals and expectations a little. My pockets aren't deep, so I'm not buying ANYTHING in the short term that doesn't already have to be replaced (with the exception of the programmer). But the things that DO have to be replaced are getting replaced with the most efficiency enhancing components possible. So I'm not spending money on parts to save money at the pump -that's just illogical in most cases. Also, I am not expecting to double my mileage or even close to it, but every little bit helps, right?
AppelH- They don't care about emissions in Arkansas, so I'm not paying $$ for a new cat. I love the good 'ol South, lol! As far as tonneaus, I know the debate on whether flat tonneaus actually reduce drag. You never see fastback or "roof to tailgate" tonneaus because they aren't commercially made for our trucks -or any pickups as far as I've been able to find. In fact, the only ones I've seen commercially made are for HUMVEES, '70s Ford Broncos and current Jeep Wranglers. Aerodynamic theory and anecdotal data support the idea that the fastback design should significantly reduce drag at 50+ mph compared to flat covers or open beds, so I'd like to try my hand at making one sometime down the road. Besides, if it doesn't reduce drag, I still think they look bad*** (google bronco fastback tonneau and see what I mean). I thought I put the thread in the right place because future discussion of my engine rebuild will be of a very technical nature, but if it needs to be moved, that's totally ok with me.
Hey You- I expect to see 1mpg improvement from locking hubs because my exact truck in 2WD trim with the same rear end gears nets 1mpg better according to manufacturer specs. I thought hubs were $250, but apparently, Dana 44s requre a $1300 kit so forget that! As far as open element filter. . . two things impede fuel efficiency from the intake system -air restriction which hurts volumetric efficiency, and air temperature which is positively correlated with fuel economy and negatively correlated with power. The big open element filter flows better than anything, so air restriction is no longer a problem, and since it gathers air from directly above the block, it should function as a warm air intake as well. What are your thoughts?
Arde- I have no idea what the compression increase will net me. But if it improves mpg from 13 to 14, it saves me ~2 cents/mile, or $6.25/tank if gas is $3.25/gal. That's more than enough to offset the 10 cent/gal price difference of premium fuel. But who knows if I'll see even a 1 mpg increase from this. Has anybody raised their compression?
Gary-L- I agree completely. I hope my introductory paragraph clarified that I'm only replacing what's broke, not spending money replacing working parts for the sake of fuel economy -at least not in the short term.
merc225hp- Thanks for the tips! Still gonna do the kegger mod, though. After all, it's free!
utmkiv- I kinda like the A/C, but girls REALLY like the A/C. If I ever want to have a girl in my truck again, A/C delete is not an option, lol.
AppelH- They don't care about emissions in Arkansas, so I'm not paying $$ for a new cat. I love the good 'ol South, lol! As far as tonneaus, I know the debate on whether flat tonneaus actually reduce drag. You never see fastback or "roof to tailgate" tonneaus because they aren't commercially made for our trucks -or any pickups as far as I've been able to find. In fact, the only ones I've seen commercially made are for HUMVEES, '70s Ford Broncos and current Jeep Wranglers. Aerodynamic theory and anecdotal data support the idea that the fastback design should significantly reduce drag at 50+ mph compared to flat covers or open beds, so I'd like to try my hand at making one sometime down the road. Besides, if it doesn't reduce drag, I still think they look bad*** (google bronco fastback tonneau and see what I mean). I thought I put the thread in the right place because future discussion of my engine rebuild will be of a very technical nature, but if it needs to be moved, that's totally ok with me.
Hey You- I expect to see 1mpg improvement from locking hubs because my exact truck in 2WD trim with the same rear end gears nets 1mpg better according to manufacturer specs. I thought hubs were $250, but apparently, Dana 44s requre a $1300 kit so forget that! As far as open element filter. . . two things impede fuel efficiency from the intake system -air restriction which hurts volumetric efficiency, and air temperature which is positively correlated with fuel economy and negatively correlated with power. The big open element filter flows better than anything, so air restriction is no longer a problem, and since it gathers air from directly above the block, it should function as a warm air intake as well. What are your thoughts?
Arde- I have no idea what the compression increase will net me. But if it improves mpg from 13 to 14, it saves me ~2 cents/mile, or $6.25/tank if gas is $3.25/gal. That's more than enough to offset the 10 cent/gal price difference of premium fuel. But who knows if I'll see even a 1 mpg increase from this. Has anybody raised their compression?
Gary-L- I agree completely. I hope my introductory paragraph clarified that I'm only replacing what's broke, not spending money replacing working parts for the sake of fuel economy -at least not in the short term.
merc225hp- Thanks for the tips! Still gonna do the kegger mod, though. After all, it's free!
utmkiv- I kinda like the A/C, but girls REALLY like the A/C. If I ever want to have a girl in my truck again, A/C delete is not an option, lol.
Last edited by Big Green 360; 10-28-2013 at 03:06 PM.
#10
Your 2wd also didn't have that nice heavy axle up front, or a t-case. Weight makes a big difference too.
Cooler air is denser, therefore, can carry more fuel, so, more power. Don't have to get into the throttle quite so hard for the same acceleration. The stock intake system isn't all that bad. A good, free-flowing filter is all you really need.
You should be able to grab knuckles and out, from another D44, to get your locking hubs though.
Cooler air is denser, therefore, can carry more fuel, so, more power. Don't have to get into the throttle quite so hard for the same acceleration. The stock intake system isn't all that bad. A good, free-flowing filter is all you really need.
You should be able to grab knuckles and out, from another D44, to get your locking hubs though.