Cummins 4BT powered TJ....

[4speedfunk]

Here's a few pics of my friend's TJ project. This drivetrain was originally slated for an H3 build but, he got cold feet and switched over to a TJ platform. Shown is a TJ frame (mostly), Dana 60 front, 14-bolt FF rear, NP-205, NV-4500 trans. 3-link front/4-link rear coil-sprung all around. He will be moving the front axle forward 10", and the rear axle backward 4". The motor is slightly marinated...hopes to get 290hp from it. Gears are 3.70, and tires will be 37"s. This will be a driver and he hopes to crack 25mpg with it. 4BT Jeeps are not anything exotic...seems to be alot of them cruising arouond but, this one is a tad more involved than just a motor swap. Its sure to be an interesting rig so I thought I would post up some pics.

I'm hoping he gets frustrated and gives up, as I would like to stuff the motor & trans into an H3 -LOL....

 

[RamRod]

By the components in the photo's (axel truss etc.) looks like it is going to be a sexy build!

Thanks for posting, don't forget to post updates! Its always good to see whats going on outside our little hummer world!

 

[High Five H2]

looks like a rad build. I wonder why he went with an NV4500 instead of a 6 speed, they bolt right up and .. you know, 6 speeds. personal preference, i guess....

 

[4speedfunk]

Latest pics. Intercooler close ups for Casey...

 

[CaseyS]

The high mount turbo makes things so much easier. Never realized jeeps had that much height under the hood. He is going to have to over fuel the hell out if that hx 35/40 turbo to spool it. Not the most streetable or trail friendly turbo. But to each his own. Thanks for the pics.

 

[cgalpha08]

The high mount turbo makes things so much easier. Never realized jeeps had that much height under the hood. He is going to have to over fuel the hell out if that hx 35/40 turbo to spool it. Not the most streetable or trail friendly turbo. But to each his own. Thanks for the pics.

Can you explain that real quick? The difference between having the turbo high vs low mounted. I'm just curious.

 

[justin94tt]

Coming from import vehicles and owning multiple turbo cars including 94 Supra. Top mounted turbos are simply easier to access if something goes wrong. Don't know if that is his reasoning or not, but definitely mine.

 

[4speedfunk]

Chuck is just now getting the motor lined out. It's way modified. Not sure of the exact mods but its more than the typical bread truck build. Currently this jeep has no brakes, electrical, or dash installed. He sent me a video of him driving around in a field last Sunday....seems to run pretty good.
It's got a brand new NV-4500 and twin-stick NP-205. These are untested so he cycled both thru all modes. He dumped the clutch at an idle in low range and it barked the 37" H1 tires and took off, (pretty scary with no brakes!). Axles are 3.73...d60 front & 14-bolt rear. Like most builds...getting it to this point is an accomplishment but now the real work starts. It's prolly 6 to 12 months away from being totally turn key.

 

[SuperBuickGuy]

hmmmm... the first post pictures don't work. Too bad, sounds like a cool build.

I keep coming back to the issue with the NV4500 and NV5600 of weight. While they're certainly indestructible (presuming fix of the early 5th gear issue), does it really need it? 37s really aren't that big and in my fuzzy math, I figure he added at least an extra 1000 lbs to the truck with the cast iron 205, 300# NV4500 and the axles. So what kind of wheeling is he planning with this? some rock bouncing?

 

[4speedfunk]

Well...this guy has a history of destroying vehicles, so it's safe to assume he will be floggin it pretty good. I've been involved since the inception and I would describe it as a streetable crawler.
The choice to use 37s was largely based on the H1 wheels & tires. I got a local connection that grinds up 3000 humvees a month...so 37"s & bead locks can be had for very little. I personally think 3.73 gearing is a tad high, and a creeper kit for the 205 would've been nice.. But we'll see after its all done. Like I said...it takes a long time to get things perfected.
Sorry about the pics....that's some sort of global Java issue or something. After June of 2015...it seems the net only supports pics uploaded from my phone. Pics uploaded from my PC no longer appear.

 

[SuperBuickGuy]

alrock is a hero, he fixed the pics issue - it looks pretty cool. I can't believe he apologized - it's not like we're paying for a service, but rather enjoying his hard work for free... there really is no need, still a nice gesture and typical of the management here.

37s with the low range from the NV4500 should be okay and diesel torque should be okay? I tend to build to a final build - which usually means leaving the gear ratios alone until I drive it.... mine is about the same weight and I wonder, since I have a 5 speed, how I'll like the 4.56 gears... as you said, it takes time to dial it all in.

 

[MaxPF]

looks like a rad build. I wonder why he went with an NV4500 instead of a 6 speed, they bolt right up and .. you know, 6 speeds. personal preference, i guess....

The only real difference between the 5 and 6 speed manuals are closer spacing between direct and the next lower gear. This is helpful for a 3/4 or 1 ton truck that tows real weight, but not really needed for something like a Jeep. The 5 speed is also cheaper, shorter, and lighter.

 

[CaseyS]

Can you explain that real quick? The difference between having the turbo high vs low mounted. I'm just curious.

So there are several ways to mount the turbo on the 4bt. The standard 4bt manifold has the outlet pointed down between the 3 and 4 cylinders. A low mount turbo will be mounted below the manifold. The manifold is reversible in that it can be flipped with the outlet pointed upward between the 1 and 2 cylinders. In this case the turbo is mounted on top of the manifold (high mount).

To add even more options, some take a 6bt manifold and chop the outer 2 runners and plug them to make the outlet centered between 2 and 3. This can be mounted with the outlet either up or down giving more options on exact turbo location and orientation.

In the case of the h3, I feel low mount is almost required due to interference with the engine bay. A high mount turbo will barely clear the hood, if at all, and it would put the exhaust routing right into the heater lines at the firewall.