Making the most of a stock 6.2

[MudmanHMMWV]

I was talking this over with a mechanic friend of mine, since fuel mileage is important to me. He told me that if I intended to keep the old 6.2, or since I'm somewhat of an apocalypse nut an older diesel motor, that I should put an forced induction system on it. The two words that left his mouth actually made me cringe a little. He suggested a twin turbo set up, along with a few other gas saving mods that one can put on a motor but those aren't that big a deal.

I was actually wandering if anyone had actually attempted this, while it sounds like a good idea it also sounds like it would be more hassle then it's worth. There are a few other things like modified exhaust manifolds to decrease back pressure and such as well as lightening the frame as much as possible. So now down to the nitty gritty I find that I would actually like some advice on all of this from someone who actually owns a HMMWV.

So anyone at all who can help me, I would like your best opinion on the turbo situation as well as any other small, I stress this next part, mods that don't involve computers and such.

Thanks

 

[jwaller]

rip it and put a 6.5 turbo in. cheaper than some home made 6.2 turbo setup.

 

[MudmanHMMWV]

The newer 6.5 turbo relies heavily on a computer. I'm not worried about the cost anyway, this isn't something that I am going to do all in one weekend. I'm looking at around four months at least, since I will only be able to work on it during the weekends. I like the older 6.2 because well it's mostly non-electronic, and if it turns out I have a different motor to work with I will just get an older motor to put in it. I intend to completely rebuild the motor from the ground up so it's going to be expensive as **** anyway. Aside from that I am looking for other ways aside from stepping up the motor or switching to gas to get better gas mileage out of it.

 

[colt45727]

You could put a supercharger on it. They made a kit for the 6.5s but it bolts onto the 6.2 fine. Theres a video on youtube "supercharged diesel". Angry Iron also put a supercharger on their Hmmwv (berserker). Look up the website anrgy iron.com. I talked to the motor guy that they had do it (dieseldepot.com), he recomended new 6.5 head studs and gaskets. You also need to expand the fire wall behind the block because the intake comes from the back to the front. Both angry iron and the guy I talked to said its a whole nother machine with it on.

Also a write up on flashoffroad.com/ and marinediesel.com still makes a kit for the 6.5 marine engine

 

[TedG]

A military hmmwv 6.5TD does not rely on a computer. It is mechanical. The 4L80E uses a TCM. I find it funny that you are concerned about fuel mileage with an mv! lol

For a standard 6.2 in a hmmwv, make sure you have the rubber boot on the air filter box intake side. It is the one used for deep fording and it will gain you the most for the least amount of $.

If you want to keep the 6.2, then you can, with a LOT of work, use a turbo from a 6.5. You will have to mount the turbo on the top left side and reroute "everything". It has been done and it wakes up the 6.2.

Other than that, I am with jwaller. 6.5TD in a hmmwv is nice.

 

[papaydsailor]

Now you are able to improve fuel economy up to 31% by simply installing our Selectable 2wd/AWD/4wd Transfer Case! Simply remove your stock All Wheel Drive Transfer Case and install the Predator Transfer Case for a direct replacement and an instant fuel economy savings. On average we documented a 31% increase in fuel economy. So with the average 6.2 stock Hummer getting 13mpg, you should now be getting apx 17mpg! The shifter acts exactly the same way it did before except that you now have a 5th gear selection, all the way forward on your gear selector, which is the 2wd setting. No draw backs or compromises at all! By selecting the 2wd setting, you are now disengaging power going to the front drive shaft and gearing thereby reducing wear and friction wich results in an increase in fuel efeciency and performance. Available for all model H1's and HMMWV's."

but um if you look at the np242/ nv242 they are the same thing as the HMMWV 242hd minus the vamp cooler thing and of course with a narrower chain.

All 242 transfer cases can be part-time cases, no $2500.00 needed just get the shift fork and linkage from any xj,zj,wj jeep with the np242, also a ton of dodge dakotas and durangos and rams have the nv/np242.

They are the same case, am general just tossed the 2wd shift fork.

Thousands of jeep owners, my self included ditch their nv249/ np247 transfer cases for the np242 case, just fort he wonder of these options:

2wd hi
4x4 part-time hi (locked center diff)
4x4 full-time hi
n
4x4 part-time lo (locked center diff)

The stock 242hd HMMWV case it a dang strong Transfer Case.
For a lot less than the CORE CHARGE, that these PREADATOR guys charge you to can have 2wd for your hummer.

 

[transman]

Papaydsailor, thanks for the eyeopener. I happen to be sitting on 14 H1 242s that Iwould be happy to modify for 2hi operation for FAR less than predator. these are new units with the 4 bolt extension housing. Gotta luv GL for bargains like this. (I'd gladly give it up for less govt. waste of taxpayer $ however)

 

[supermechanic]

In stock form, the 6.2 has a nasty habit of pulling out #4 main web , can't say that a turbo would make things any better.

 

[MudmanHMMWV]

That all is really helpful, especially the information about the transfer case. I will look into it, and while I know it will be a lot of work I'm hardly scared of putting time into it. While I know that fuel economy is never going to be stellar I intend to get it as good as I can, it's all part of the fun in my opinion.

With the 6.5T that I looked at, as well as any that my friend informed me off. All relied heavily on a computer system, for what reason I don't really care but low tech is important.

 

[papaydsailor]

yes, 6.5Turbo with 4L80E over drive, differential E locker relied heavily on computer not good if you go off roading and deep water fording all the time like i do .no need to hook it up to computer checking module for TCM check whenever something goes wrong. plus you have to upgrade your brakes too if you want the 6.5t speed to keep the wheels from skidding in a sudden stop in traffic and you have to change your brake pad all the time if you decided not to. plus i found it hard to control the steering at a high speed in a freeway traffic. thats why i decided to keep my 6.2NA with an upgraded NP242 with 2WD. plenty of space, few part to fix that a regular soldier guy could do the way it was design to be. if i can only keep the 6.2 engine noise down in the cabin to listen to my stereo then i would be using it as my everyday vehicle since i dont drive uphills all the time which make it too slow for 6.2.

 

[MudmanHMMWV]

yes, 6.5Turbo with 4L80E over drive, differential E locker relied heavily on computer not good if you go off roading and deep water fording all the time like i do no need for TCM wirings. plus you have to upgrade your brakes too if you want the 6.5t speed to keep the wheels from skidding in a sudden stop in traffic and you have to change your brake pad all the time if you decided not to. plus i found it hard to control the steering at a high speed in a freeway traffic. thats why i decided to keep my 6.2NA with an upgraded NP242 with 2WD. plenty of space, few part to fix that a regular soldier guy could do the way it was design to be. if i can only keep the 6.2 engine noise down in the cabin to listen to my stereo then i would be using it as my everyday vehicle since i dont drive uphills all the time which make it too slow for 6.2.

If you are really looking to keep the noise down you could always Dynamat the interior. I know it's not the lightest addition but it will kill a lot of the noise from outside the cab. Though I'm not sure how water proof it is, I know that my old thunderbird made a racket until I put down dynamat. Well it didn't make as much of one, you would really have to find out if it was water proof.

 

[Tanner]

There are also spray-on coatings available for heat shedding/sound absorption use - the spray-on coatings are nice from the standpoint that they won't absorb/trap moisture like some add-on sound-absorbing mats will -

'Tanner'

 

[67_C-30]

There are also spray-on coatings available for heat shedding/sound absorption use - the spray-on coatings are nice from the standpoint that they won't absorb/trap moisture like some add-on sound-absorbing mats will -

'Tanner'

Ditto! I highly recommend Lizard Skin. It is the best I've found. They come in 2 gallon buckets, and allows you plenty to do both the top and bottom sides of the floor.

LizardSkin 50115 - LizardSkin Sound Control Insulation - Overview - SummitRacing.com

 

[MudmanHMMWV]

Wow, a whole bunch of new things to consider, swapping the transfer case, and all such other little things. Yay, looks like my weekends will be full up.

 

[papakb]

contact please

Pappydsailor,

A former FT would like you to contact him regarding the mod to the transfer case. Years ago I modded the trans to add park to it and wrote it up for Supply Line. I'd like to mod my transfer case but would like to speak to you about how it's done before I do it and write it up. Please contact me at papakb@yahoo.com or at 408-440-6067.

Thanks

Kurt Lesser

 

[transman]

The secret of 2wd in a hmmwv 242 is not the lack of a shift fork . Both needed forks are there. A "shift cam" change is required. I have several new GL units available. modified or not.

 

[militarysteel]

the best way to increase the horsepower and fuel millage with your 6.2 is to remove it and install a 6.6 duramax kit, you will be quite satisfied!

 

[MudmanHMMWV]

the best way to increase the horsepower and fuel millage with your 6.2 is to remove it and install a 6.6 duramax kit, you will be quite satisfied!

One problem, a 6.6 Duramax kit, well all the ones I have looked at use fuel injection....fuel injection is irritating to deal with when a part of it breaks so no thanks. I would rather just deal with a carburetor, sure it's outdated and rarely used anymore but it's just so much better in my book.

 

[Tanner]

Ummm... all diesels are fuel injected, not carbureted...

'Tanner'

 

[MudmanHMMWV]

Looks like I need to go over my notes again.....then it could also just be being forgetful. Yeah, leave it to me. Still even though I haven't been the most attentive when it comes to that no I think I keeping the stop 6.2 is the best.