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Discussion Starter #1
To start: I've been following this site closely with all the projects and builds people are doing and it's awesome. This site has been great for doing research too and I've done months of it for this project. In short, PBB kicks ass.

I bought a '99 TJ this past week. I found it in an auction down the road from my house and it was a great deal so I got it. It's a piece of shit but I love it. I am planning on building it up to a degree of insanity similar to most Pirate4x4 members and can't wait to do it! I don't plan to get started until early this Spring, but I've been carefully planning it out and the garage is steadily filling up with parts for this project. It should be a bad bitch when it's done.

So basically I'm starting with this:




My dad and I worked on it some to get it ready for inspection and registration. Scored a set of new door skins and 5 almost new tires on wheels already balanced for free from a friend. Still need to somewhat repair the fender so the blinker sits in there. Fuckin laws... The "new" wheels had the cancer pretty bad and we didn't want it to spread so we did what any loving Jeep owner would do: cover the shit with grease and call it good.



And at the end of the day:


These are my plans so far for the finished build:

Suspension: Clayton Offroad Long Arm setup, 4 link rear, with coils for about 2.5-3" of lift. I'm gonna keep the Jeep as low as possible. Rest assured the sheetmetal will see plenty of Sawzall action. I'll trim up the hood and fab up my own flares. It'll be similar to AEV's "Highline" fender and hood kit or whatever they call it.

Axles/Wheels/Tires: Looking for a D60 front, and either a D60 or 14 bolt for the rear. 4.11 gears and I'll probably install a locker in one or both. Tires will be 37's or larger, maybe Irok 39.5's probably on Hummer wheels. I like them because 1) I won't have to grind calipers like I would to fit a 15" wheel, 2) I need a lot of backspacing so the po-po doesn't pull me over every other day for tires sticking way out past the flares, and 3) because of the military aspect behind them along with the fact they are beadlocks.

Engine and Tranny: The motor is a Cummins 3.9L 4 cylinder diesel out of a retired Frito Lay delivery van. It's turbocharged and has the air to air aftercooler on it. It makes around 120hp and around 400ft-lbs of torque. I'll probably turn up the fuel screw on the injection pump a little and give it some more fuel. Some guys have these 4BT's running around 250+ hp! The transmission will be an NV4500 5 speed out of a Dodge Cummins truck. I chose this because it's beefy and will hold up to the torque and because it's easy to adapt to my motor using standard Dodge parts. Still looking for the transmission though and it's not easy to find...

Other stuff: I'm entertaining the idea of stretching the wheelbase out a few inches. "Might as well do it when I have the shit taken apart", right? Not sure though becuase I don't want too many things to do at one time. Summer is my only real chance to get as much done as possible and hopefully complete it. I'll also be fabbing up armor, skids, bumpers and some roll cage reinforcement.

This is what's replacing the Jeep's 4 banger:



I'm in the process of completing a crankshaft main seal job on it as well as a preventative timing gear case fix and oil pan repair job:



I've mainly been buying drivetrain parts so far. The clutch setup is massive and can handle 700ft-lbs of torque. I bought it slightly used:







Here's the flywheel housing/transmission adapter plate and bellhousing for the NV4500:


When I go home for Christmas break I'll be checking all the junkyards in the area, mainly for the axles. Let me know what you guys think. I'd like to hear any and all feedback/comments/suggestions about this build and hey, maybe a little flaming if that's in order.

I can post a build thread when I start it if people are interested...

Thanks for checking this out,
Mark
 

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Sure...keep posting up...Id like to see more.
 

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Wow, this is just about the same thing I'm starting on now. I still have to get a 4BT, but I have the NV4500, bellhousing,and motor plate. I'm starting out with a '99 TJ tub and frame, and a Dana 60 HP out of a '79 F250. I want to use either an Atlas or Stak transfer case(if they make one for the diesel NV4500 29 spline). I'm going to stretch the wheelbase and was thinking about airbags over coilovers, but that cost big $$$$. I'll post some pictures as the building progresses. I have seen a nicely done YJ with a 4bt that worked pretty good.
 

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Discussion Starter #5
Yeah I'll weld on extra material to the sides of the frame rails to handle the extra weight. It really shouldn't need much though, considering that the 4.0L is a pretty heavy motor by today's standards anyway.

That nice YJ you were talking about was in Diesel Power Magazine not too long ago. It eventually went on eBay but I don't know what happened to it from then on.

I was thinking about getting the NV4500 from Advance Adapters. Maybe they'd cut me a deal for the the tranny with an Atlas? Does anyone know where to find a reasonably priced reman or used NV4500? Any PBB vendors?It's been slim pickens on eBay for the last few months and other places want over $2k! :eek:

And I'll keep pictures coming. Thanks for your responses.
 

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Discussion Starter #7
By the way, the steering will be a high steer setup with full hydro. I plan on doing the same thing Billavista did on his buggy. There's a write up on it in the tech section if you're curious.

The power steering pump on my diesel engine has a third output line for hydroboost brakes too. I need to do some more research on brakes, but I'm thinking about the Grand Marquis master cylinder setup that a lot of people have successfully done.
 

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I like the entire thing. Deph keep a build up thread going on this.

Ome thing I would change is that you said you were going to gear it to 4.11 I personaly dont like that Idea with the size tires you want to run and that the fact that you say you are going to drive this on the street. My buddy is on 37's and he went from 4.11 for his 35's to 4.88's for his 37's. Im running 33's and geared to 4.10 Thats all about to change tho. I m going to go to either 4.88's or 5.13's and redo my suspension and swap the 4.0 with a V8. Just my opinion. But it would dephinately do better on road if you geared lower for those tires.
 

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def. a cool build idea; would love to see pictures. i'll second the remarks about the lower gearing. doesn't seem like the engine would weigh much more than a 4.0 or 350. four link f/r with coilovers would def. be sick on that thing. best of luck
 

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Is full hydro street legal in MD? Just a thought Good luck, and keep us posted!
 

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Discussion Starter #12
Is full hydro street legal in MD? Just a thought
:confused: I hope so. I've been trying to research the laws among many things but can't find specifics. I looked on a "fix it" ticket for steering. It's on there, but I think it's meant for a vehicle that has blatantly dangerous steering - like one time I saw a tie rod fastened to a knuckle with a clothes hanger. I'll have to call the DMV and see if they can't tell me, although I'm sure they'll put me on hold for half an hour then tell me to call somewhere else.

Diesel and gas applications as far as gear selection in axles goes is different. My engine's peak rpm is 2500. That's not even half of what most gas motors can run. Aside from that, this engine makes peak torque and gets the best fuel economy between 1500 and 1700 rpm. Since the rpm band is so low, I can't put in lower gearing. 4.56's or worse, 4.88's would give me a top speed of "way too damn slow" on the highway.

What's cool though is that with this low rpm band, I can run a range of tires from 35" to about 40" and still stay in the efficient operating range :smokin:

Here's some links to a speed calculator I used to figure this out. Keep in mind max torque is made between 1500 and 1700 rpm, and the lowest fuel consumtion (measured in lb/BHP-hr) is between 1500 and 1900 rpm.

35's with 4.11's: http://www.xse.com/leres/bin/gearra...=diameter&diameter=35.00&circumference=116.24

37's with 4.11's: This I think is probably the best sized for the application: http://www.xse.com/leres/bin/gearra...=diameter&diameter=37.00&circumference=109.96

and finally, a 39.5 with 4.11's: http://www.xse.com/leres/bin/gearra...e=diameter&diameter=39.5&circumference=116.24

You can change around the paramters if you want.

These engines used to move huge, very non-aerodynamic trucks that were heavily loaded and they did it with good power and fuel economy. I think though that a 40" tire would have a much higher moment of intertia than say a 37" so the engine will obviously have to work a lot harder to get a set of 40's rolling down the road or up some rocks. I'm leaning towards 37's...
 

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Ahhh...that fender will buff out...with a Sawzall

Nice :smokin: I'll be watching this... I want to stuff a 4BTA into my Scout, of course at this point I'm still dreaming, where as you have one sitting in your garage.
 

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Definatly watching this. Full hydro is illeagal as far as i know. There needs to be a mechanical connection between the wheel and the box.
 

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Discussion Starter #18 (Edited)
Full Hydro Steering

To the vehicle law books I say :flipoff:

However, if that's the case then it is what it is. I'll just stick with a hydro assist setup. I'll probably just use the existing steering box and tap it for the lines to the ram. At least this way I'll drive with a legal setup and I'll save some $$ since I think the full hydro steering setup from POS runs around a grand or so.

So long to the idea of a four link front :shaking:
 

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Ferrell's YJ said:
Ome thing I would change is that you said you were going to gear it to 4.11 I personaly dont like that Idea with the size tires you want to run and that the fact that you say you are going to drive this on the street. My buddy is on 37's and he went from 4.11 for his 35's to 4.88's for his 37's. Im running 33's and geared to 4.10 Thats all about to change tho. I m going to go to either 4.88's or 5.13's and redo my suspension and swap the 4.0 with a V8. Just my opinion. But it would dephinately do better on road if you geared lower for those tires.
Call me crazy, but I am happily running 4.10's and 40's with just my stock 4.0l. I was going to regear but didnt have money and 2 years later I still havent because I am happy with how it drives on the street. I can hold 70 easy going through all of CO's mountain passes on I-70. Sure its not a rocket ship but a jeep on 40's doesnt need to be anyway.
 

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I don't know about a diesel combo in a TJ but I know my 4.0L/AX15 and 5.13's struggled in mountains/hills to maintain 70 in 5th gear with 38.5's.

Bro runs a healthy 4.2L/TF999 and 4.10's with 38's and it slightly worse than mine holding that speed, but he has 1:1 drive gear...

I would assume a 4bt could hold decent in over drive with 4.10's or 4.56's maybe, but like a said, pure assumption...
 
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