This is a long post split into two parts because of forum image count limitations. It will be of interest to anyone who has ever thought about a water mist injection system either for the purpose of lower EGT's, lower IAT's or increased fuel mileage. It uses only a few parts that I actually hard to order online (mainly the nozzles and boost switch), and mostly uses parts that can be found on the shelf at your local air/hydraulic shop, agriculture or RV supply, and/or hardware store.
This thread is a follow up to a lengthy discussion of water mist injection on the 6.5 from this thread:
http://www.dieselplace.com/forum/showthread.php?t=417460
After deciding to take a pass on a hydrogen injection system (because of widely publicized detonation issue with HHO and the 6.5) my attention turned to WMI - Water Mist Injection.
I wanted the system primarily for it's fuel economy benefits, with lower EGT's/IAT's and engine cooling benefits while towing also in mind - I spend a LOT of time towing every summer with double trailers and IAT's have always been a challenge, with engine cooling also being a challenge on some long/extreme grades. Although the fuel economy aspect has never been studied in depth with the 6.5 in specific, a moderate MPG improvement with injecting water alone has been proven in other diesels. In the end, this system amounted to a huge experiment.
I looked around at many, many options for kits..and it all came back to $$$$ - it was easy to spend well over $500-$750 or more for a full optioned kit. Hoping for a 1-3MPG fuel economy outcome, the return on investment was WAY too long. I knew I could source some parts (mainly, the nozzles) from WMI suppliers, and get most of the rest off the shelf locally...so this is the way I went.
- The tanks were obtained for free from one of my customers at work- score big $$$ savings right there. These are LARGE tanks, but given how I intend to have the system active quite a lot (not just while pulling grades like many setup their system for) I need to carry a considerable amount of water since my system will be basically injecting 100% of the time while the wheels are turning. With some resourcefulness it's possible to pickup something to carry your water at little or no cost.
- I decided to use small PEX plastic line to feed from my water tank(s) in the bed of my truck. This was the same line that WMI kits use beyond the compressor/pump anyways, so I saw no reason to not use it for the ENTIRE system. Benefit: 50 foot roll for $11.
- The couplers, fittings, quick connectors, etc were all sourced from my local Princess Auto. For the USA members, I'm guessing there is an equivalent store with the same assortment. I spent a surprising amount of money on all of the above (probably about $50) but I ended up with a very modular system as a result - nothing is difficult to replace - if a line is damaged somehow I can zip it out and replace it entirely in about mere minutes.
- I opted to use a solenoid from Princess Auto as well to ensure positive water flow cutoff. $20, versus $40 or more from WMI suppliers online, not including shipping. Solenoid was specifically specified to handle liquids as well as air - important, since some are rated air-only.
- Most importantly, the pump. I utilized a simple agricultural pump capable of 75 PSI maximum. AG-Pumps are built to withstand chemicals (versus an RV pump which is not) so should I decide to add alcohol to my system later it won't be a problem.
Yes, 75 PSI is MUCH lower than most pumps for WMI kits generate, but I was very careful to ensure that I spec'd the nozzles accordingly, and was able to find a supplier that assured me their nozzles misted fully at only 40 PSI above boost levels. Since I run about 13 PSI Boost max, I only needed a pump capable of generating at least 53 PSI (simple math), so 75 works just fine.
Sure enough, when bench testing, even at only 30 PSI of water pressure (before we turned the pump up) it provided an excellent fine mist from the nozzles.
Benefit: Only cost $99. I kick myself for having missed it on sale as only a week or two back it was on sale for $79! The USA based members can probably find these pumps for $60-$80 routinely, I suspect.
The only thing I ordered from a WMI supply house was the nozzles, and a simple boost control switch. Total cost was around $25.
I opted for 3 nozzles, with intention of running two at a time, with one of those two on a shut-off valve. I ordered a 10GPH, a 5GPH, and a 7GPH. We used the 10 and the 5 to begin with and the 7 was for experimentation purposes.
So, this afternoon, once again with fellow DP member Racer55 (and his most excellent workshop!) we started the install. Lets get started with the pics:
My water jugs. Not bad for free, and they fit nicely in front of and behind my fifth wheel. The bed rails for the fifth wheel, along with some cheap ratchet straps make for perfect (and easy) mounting in the bed of the truck.
Here they are mounted in the bed. Excuse the bed, it's rather dirty, picture was taken at night and I hadn't cleaned things up, but you get the idea. A 2x4 to keep them aligned, and a few ratchet straps looped through my fifth wheel bed rails and they are secure.
Quick-connector threaded into the bung of one of my water jugs:
As mentioned, these were the sorts of fittings that added cost to my build, but they have the huge advantage of being easily connected/disconnected and making the system 100% modular.
Removed intake manifold in preparation for drilling the holes for the nozzles:
The intake manifold gasket was just fine upon removal. Ironically I did have a spare around my garage somewhere, but couldn't find it when I looked. Never needed it afterall.
Manifold off and center punched in prep for drilling:
Pump out of box, getting ready to hookup gauge to check pressure and then to bolt in.
Another view of the pump with the pressure regulator at the end. Notice more quick connect fittings:
Here's the relay I used to feed power to the entire kit and kaboodle. For those who remember my ill-fated glowplug override circuit, this is the same relay. It was still under my hood and wired to a switch on my dash, so it was screaming to be repurposed. Saved me some wiring.
So, I ran the PEX line through the same hole in the front of my bed that my fifth wheel electrical wiring goes through. Here's the spare I had - as you can see, 50 feet goes a long way. Yes, my truck bed is a mess - I had just dropped off a load of garbage at the dump on the way up to Racer's. :
PEX line heading forward:
I ended up running the line forward through the same brackets that carry the emergency brake cable. Nicely grommeted, and lots of space to spare:
In the drivers side wheel well it pops nicely up off the frame and into the engine compartment.
...then I stopped to admire Racer55's new hoist.
Did I mention we had a roaring fire going in the fireplace and it was cozy warm inside while it pissed rain outdoors?
This thread is a follow up to a lengthy discussion of water mist injection on the 6.5 from this thread:
http://www.dieselplace.com/forum/showthread.php?t=417460
After deciding to take a pass on a hydrogen injection system (because of widely publicized detonation issue with HHO and the 6.5) my attention turned to WMI - Water Mist Injection.
I wanted the system primarily for it's fuel economy benefits, with lower EGT's/IAT's and engine cooling benefits while towing also in mind - I spend a LOT of time towing every summer with double trailers and IAT's have always been a challenge, with engine cooling also being a challenge on some long/extreme grades. Although the fuel economy aspect has never been studied in depth with the 6.5 in specific, a moderate MPG improvement with injecting water alone has been proven in other diesels. In the end, this system amounted to a huge experiment.
I looked around at many, many options for kits..and it all came back to $$$$ - it was easy to spend well over $500-$750 or more for a full optioned kit. Hoping for a 1-3MPG fuel economy outcome, the return on investment was WAY too long. I knew I could source some parts (mainly, the nozzles) from WMI suppliers, and get most of the rest off the shelf locally...so this is the way I went.
- The tanks were obtained for free from one of my customers at work- score big $$$ savings right there. These are LARGE tanks, but given how I intend to have the system active quite a lot (not just while pulling grades like many setup their system for) I need to carry a considerable amount of water since my system will be basically injecting 100% of the time while the wheels are turning. With some resourcefulness it's possible to pickup something to carry your water at little or no cost.
- I decided to use small PEX plastic line to feed from my water tank(s) in the bed of my truck. This was the same line that WMI kits use beyond the compressor/pump anyways, so I saw no reason to not use it for the ENTIRE system. Benefit: 50 foot roll for $11.
- The couplers, fittings, quick connectors, etc were all sourced from my local Princess Auto. For the USA members, I'm guessing there is an equivalent store with the same assortment. I spent a surprising amount of money on all of the above (probably about $50) but I ended up with a very modular system as a result - nothing is difficult to replace - if a line is damaged somehow I can zip it out and replace it entirely in about mere minutes.
- I opted to use a solenoid from Princess Auto as well to ensure positive water flow cutoff. $20, versus $40 or more from WMI suppliers online, not including shipping. Solenoid was specifically specified to handle liquids as well as air - important, since some are rated air-only.
- Most importantly, the pump. I utilized a simple agricultural pump capable of 75 PSI maximum. AG-Pumps are built to withstand chemicals (versus an RV pump which is not) so should I decide to add alcohol to my system later it won't be a problem.
Yes, 75 PSI is MUCH lower than most pumps for WMI kits generate, but I was very careful to ensure that I spec'd the nozzles accordingly, and was able to find a supplier that assured me their nozzles misted fully at only 40 PSI above boost levels. Since I run about 13 PSI Boost max, I only needed a pump capable of generating at least 53 PSI (simple math), so 75 works just fine.
Sure enough, when bench testing, even at only 30 PSI of water pressure (before we turned the pump up) it provided an excellent fine mist from the nozzles.
Benefit: Only cost $99. I kick myself for having missed it on sale as only a week or two back it was on sale for $79! The USA based members can probably find these pumps for $60-$80 routinely, I suspect.
The only thing I ordered from a WMI supply house was the nozzles, and a simple boost control switch. Total cost was around $25.
I opted for 3 nozzles, with intention of running two at a time, with one of those two on a shut-off valve. I ordered a 10GPH, a 5GPH, and a 7GPH. We used the 10 and the 5 to begin with and the 7 was for experimentation purposes.
So, this afternoon, once again with fellow DP member Racer55 (and his most excellent workshop!) we started the install. Lets get started with the pics:
My water jugs. Not bad for free, and they fit nicely in front of and behind my fifth wheel. The bed rails for the fifth wheel, along with some cheap ratchet straps make for perfect (and easy) mounting in the bed of the truck.
Here they are mounted in the bed. Excuse the bed, it's rather dirty, picture was taken at night and I hadn't cleaned things up, but you get the idea. A 2x4 to keep them aligned, and a few ratchet straps looped through my fifth wheel bed rails and they are secure.
Quick-connector threaded into the bung of one of my water jugs:
As mentioned, these were the sorts of fittings that added cost to my build, but they have the huge advantage of being easily connected/disconnected and making the system 100% modular.
Removed intake manifold in preparation for drilling the holes for the nozzles:
The intake manifold gasket was just fine upon removal. Ironically I did have a spare around my garage somewhere, but couldn't find it when I looked. Never needed it afterall.
Manifold off and center punched in prep for drilling:
Pump out of box, getting ready to hookup gauge to check pressure and then to bolt in.
Another view of the pump with the pressure regulator at the end. Notice more quick connect fittings:
Here's the relay I used to feed power to the entire kit and kaboodle. For those who remember my ill-fated glowplug override circuit, this is the same relay. It was still under my hood and wired to a switch on my dash, so it was screaming to be repurposed. Saved me some wiring.
So, I ran the PEX line through the same hole in the front of my bed that my fifth wheel electrical wiring goes through. Here's the spare I had - as you can see, 50 feet goes a long way. Yes, my truck bed is a mess - I had just dropped off a load of garbage at the dump on the way up to Racer's. :
PEX line heading forward:
I ended up running the line forward through the same brackets that carry the emergency brake cable. Nicely grommeted, and lots of space to spare:
In the drivers side wheel well it pops nicely up off the frame and into the engine compartment.
...then I stopped to admire Racer55's new hoist.
Did I mention we had a roaring fire going in the fireplace and it was cozy warm inside while it pissed rain outdoors?