David Harris
Expedition Leader
Agree. That truck sounds great. I've always liked the sound of the 6.2/6.5. They almost sound like a big block gas Chevy above idle. Unique.
My new-to-me 6.2L Disco
- Thread starter LtFuzz
- Start date
Agree. That truck sounds great. I've always liked the sound of the 6.2/6.5. They almost sound like a big block gas Chevy above idle. Unique.
LtFuzz
Explorer
Once our block leave is over, I'm going to run down to my unit's Echo company (ground maintenance/motor pool) and see what's up. Both the maintenance platoon leaders are friends and as we switch over to MATVs/MRAPs, the HMMWVs will continue to drop off the property books. :ylsmoke:
I know for a fact they hot-rodded a couple CUCVs (port/polish, new timing gear, and they did something with the combustion chambers) during our deployment so they may have some ideas on squeezing as much out of this motor as I can.
I drove from VA to GA yesterday -- 514 miles, using 23 gallons of diesel, or 22.3 MPG. Not awesome, however I was sitting at 65-68 mph (GPS) with an ARB breaking the air-trail. If I took it down to 55-60mph I imagine I'd see closer to 25 mpg.
My goal is a 500 mile-to-a-tank truck, regardless of driving conditions (relatively speaking). Apparently lots of fun things can be done to build better performing injection pumps. Guys in lowered SWB C10s can hit 30 mpg pretty easily, I'm finding out. I think this Rover is just built a little too much for that, but it'll be fun to see how close I can get.
A/C is nice, of course, but you don't need it at any sort of altitude (even southern AZ in July is do-able because it's at 5400ft), and it adds complexity and luxury over simplicity and economy.
I know for a fact they hot-rodded a couple CUCVs (port/polish, new timing gear, and they did something with the combustion chambers) during our deployment so they may have some ideas on squeezing as much out of this motor as I can.
I drove from VA to GA yesterday -- 514 miles, using 23 gallons of diesel, or 22.3 MPG. Not awesome, however I was sitting at 65-68 mph (GPS) with an ARB breaking the air-trail. If I took it down to 55-60mph I imagine I'd see closer to 25 mpg.
My goal is a 500 mile-to-a-tank truck, regardless of driving conditions (relatively speaking). Apparently lots of fun things can be done to build better performing injection pumps. Guys in lowered SWB C10s can hit 30 mpg pretty easily, I'm finding out. I think this Rover is just built a little too much for that, but it'll be fun to see how close I can get.
A/C is nice, of course, but you don't need it at any sort of altitude (even southern AZ in July is do-able because it's at 5400ft), and it adds complexity and luxury over simplicity and economy.
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David Harris
Expedition Leader
Great mileage figures. About the same as a 300 Tdi in a built Disco, and a LOT more grunt.
LtFuzz
Explorer
I guess I was acting spoiled by being disappointed with 22mpg -- my 3.9 D1 got about 180-200 miles to a tank around town, 300ish highway and that was totally stock. Ridiculous.
I got a line on a Camel Trophy rack -- just gotta figure out how to get it shipped without breaking the bank.
Outstanding. You're breaking into new territory as I never ventured out of Maryland with it. I would be very happy with 22+ mpg. That's a low-tech diesel on a cinder block shaped vehicle.
Well done.
LtFuzz
Explorer
Yeah, I need to keep reminding myself it's a Rover pushing 5000lbs sitting on on an XHD lift.
Long term goal will be 22 mpg with a roof rack, decent load, and 32" tires at 65 mph. :victory:
You can do it. Learn how to tweak that 6.2 injection pump. There's an adjustment that dials back the pressure for more economy. I did that procedure once (turned it 1/16th of a full rotation). It could probably stand to be done again in tiny increments.
David Harris
Expedition Leader
You will also benefit from turning the fuel down a bit when you get out to higher altitude in Sierra Vista.
David
Excellent point. It will run richer as your altitude increases.
Rot Box
Explorer
Nice rig! :Wow1: Wait what am I doing in the LR forum?! lol Anyway you probably got your fill of 6.2/6.5's in the service but I figured I'd throw this out there.
The 6.2 is a great motor imo. Search around for what glowplugs are best (AC-9's or 11 can't remember...) Although these companies make some great products DO NOT use Autolite, Bosch, champion, Wellmans or any other glow plug that has a dual coil. They blow out and swell to the point you'll never get them out of the head--ask me how I know (doh).
Now for fuel mileage: When it comes time for injectors I would highly recommend buying some that have been pop tested. Most parts store injectors are not pop tested and it pays in the long run to have this done. This will improve the way the motor runs as all cylinders will fire evenly and its key to great fuel mileage. I know a guy that offers injectors and does pop testing for a good price if you're interested send me a PM. Timing should be set with a pulse meter or a luminosity meter to factory specs and it is crucial for power and fuel economy--I think injector pump timing alone will make the difference between someone who loves the 6.2 and one who hates the motor. You can not time this motor by ear and expect it to be close enough... Also don't advance your pump in hopes of getting better mileage--this is not the case on a motor with pre-combustion chambers.
Also I would try to fit a factory 6.2 filter housing and filter in there. The element will be much better than the open style cleanable unit and the stock filter also should flow more than enough air. If you need more clearance swap on an intake manifold from a 1500 pickup with the 6.2 or naturally aspirated 6.5 as they are not as tall.
I can't wait to see what you do from here! :coffeedrink:
EDIT: Also poor cold starts will be a thing of the past when the GP's (and controller if you have one) and/or ip timing is addressed. You should be able to start easily in 0* weather...
The 6.2 is a great motor imo. Search around for what glowplugs are best (AC-9's or 11 can't remember...) Although these companies make some great products DO NOT use Autolite, Bosch, champion, Wellmans or any other glow plug that has a dual coil. They blow out and swell to the point you'll never get them out of the head--ask me how I know (doh).
Now for fuel mileage: When it comes time for injectors I would highly recommend buying some that have been pop tested. Most parts store injectors are not pop tested and it pays in the long run to have this done. This will improve the way the motor runs as all cylinders will fire evenly and its key to great fuel mileage. I know a guy that offers injectors and does pop testing for a good price if you're interested send me a PM. Timing should be set with a pulse meter or a luminosity meter to factory specs and it is crucial for power and fuel economy--I think injector pump timing alone will make the difference between someone who loves the 6.2 and one who hates the motor. You can not time this motor by ear and expect it to be close enough... Also don't advance your pump in hopes of getting better mileage--this is not the case on a motor with pre-combustion chambers.
Also I would try to fit a factory 6.2 filter housing and filter in there. The element will be much better than the open style cleanable unit and the stock filter also should flow more than enough air. If you need more clearance swap on an intake manifold from a 1500 pickup with the 6.2 or naturally aspirated 6.5 as they are not as tall.
I can't wait to see what you do from here! :coffeedrink:
EDIT: Also poor cold starts will be a thing of the past when the GP's (and controller if you have one) and/or ip timing is addressed. You should be able to start easily in 0* weather...
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LtFuzz
Explorer
Thanks for the good info! :ylsmoke:
I should qualify the poor cold starts -- by poor I mean for the first start in the morning it has to crank for 5 or 6 seconds. The motor really does run like a top.
dragogt
Adventurer
Couple of threads you might be intersted in..
http://www.thetruckstop.us/forum/showthread.php?589-6.5-Diesel-Technical-Library
http://www.thetruckstop.us/forum/showthread.php?5440-Manual-Glow-Plug-Override-How-To
http://www.thetruckstop.us/forum/showthread.php?589-6.5-Diesel-Technical-Library
http://www.thetruckstop.us/forum/showthread.php?5440-Manual-Glow-Plug-Override-How-To
Glow plugs and injectors are all new with less than 3000 miles on them. Timing set by a local diesel expert/shop. Can't say that the above advice is not worth looking into, especially with the brand of GP. I don't recall the brand I installed. I did not attempt to fit a stock air filter to this engine. Might require a different intake manifold as the one installed is for the turbo(?). I do strongly support learning from others experiences as long as you don't surpass the point of diminishing return.
One additional thing about leaning a diesel for economy.....the engine doesn't run hotter as you lean, it runs cooler. Of course you will lose some performance, but in my opinion, some performance could be lost and still have a very viable vehicle overall. That truck will chirp the wheels if you try. As it is, I would not be surprised if you could tweak out a 25 mpg highway as a result of leaning. Uncorrected altitude driving would be interesting.
