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What would you do?

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Discussion Starter · #1 ·
With all this talk with Jeff @ Jeepyard, it got me thinking about reprioritizing my mods. As some of you know I'm still rockin the stock Rubicon due mainly to $$$ but also because I am well aware of the fact that once you start it is a downwards slide from there.:laughing:

That said, if you could give up all your mods to have a stronger and more efficient motor, would you?
 

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I don't think there's any way to do a diesel conversion without a fair bit of suspension beef up and probably some frame reinforcement too.
 

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In my opinion the engine is kind of a "cool factor" thing. Remember when Jeeps had 4 bangers in them? People offroaded in those things and stock they had what, 27-28 inch tires? I understand it was a lighter vehicle, but my point is that you can do just fine with the engine it comes with. I am not going to lie here and say I love the 3.8, but it does it's job.

Regear, optimize the engine if you want, but get some use out of it. Unless you just want to say you have Diesel JK, or you plan on doing some hard, hardcore offroading then I think you are fine.

Just one man's opinion though.
 

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Sure, we would all love to have a deisel. BUT, i agree with ^^... when optimized (gears and such), the 3.8 is more than enough to push the jk...
 

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I wouldn't GIVE UP my mods, if that's what your asking.

I don't know the extent of the work for the 4BT conversion, but I would probably look for the 2.8L CRD.
 

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My engine is completely unmodified, but my Jeep does some impossible shit on the trail and can go over the speed limit with 40" tires on the road. Don't let the engine prevent you from making mods to the Jeep. Thats the last thing on my mod list.
 

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I don't think there's any way to do a diesel conversion without a fair bit of suspension beef up and probably some frame reinforcement too.
A diesel is already offerred in the JK's, everywhere but here in the US, thank's to the ever more intrusive gov't.

I have a Hemi, so maybe a different point of view than some...

Those who haven't had the opportunity to drive a powerful Jeep versus a not so powerful Jeep - could be any pair of similar Jeeps for the comparison - would be suprised at what the extra torque allows. More power = more control and more capability.

You can get the power any number of different ways, new engines, new much, much lower gear, new transfer case with lower gears.... lots of ways.

Sticking with the 3.8, it means 5.38's, 4:1 rock box, rubicrawler doubler or Atlas.... All the gear that will makes the JK shine off road and makes the 3.8 a sufficient, utilitarian engine that gets the job done.

The problem with the 3.8 and the JK's, especially the JKU is that it lacks power on the HIGHWAY and there is just no way to fix that shortcoming, except major expense, like supercharger or engine swap. Older Jeep models sucked so bad on the highway that the fact that, say, a four banger YJ wouldn't hold a 70mph cruise through the mountains didn't matter much, but the JK's are so much better on the road and highway that they need a better engine for that use, imo. The reason I went for the Hemi was for on road driving, which I ultimately do a lot more of than off road driving. The power is great off road to, and don't overlook that fact that any Hemi engine has more torque at 1200rpm than the 3.8 makes at peak, but I couold have gotten the power out of the 3.8 for offroad use through gearing.

The appeal of a plenty powerful diesel to me is range and highway drivability, and like the Hemi, it would also add capability offroad as well. But it needs to fix the 3.8's highway shortcomings.

JPK
 

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The amount of money for an engine upgrade > the amount of money to make take the stock 3.8 JK and turn it into a very capable trail vehicle. I don't feel as if I have enough get up and go on the highway and would love something else in it and have been waiting for my engine to go ahead and explode (not that I'm looking forward to spending thousands on a new engine and all the changes that go along with it). I've never been out on the trail and found a place I don't have enough power to get up or over something. I usually find I want more clearance or something else needs to protecting, etc. Granted I'm not rolling with the 3.8, but I have yet to see something with a SBC with a lot more horses do something my 4.0 can't do simply on engine power alone... it just means that I was deficient in some other area.

I'm a cheap @#[email protected]! though. :laughing:
 

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Go with a biodiesel conversion so you can run your Jeep on Bacongrease.

That would also help to alleviate road rage because everyone would want to be BEHIND you, where it smells like sweet, tasty bacon.
 

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I'm doing everything in my power to make the diesel swap come to fruition.

It's said that you need 3"+ lift (have been told 4" from one source). I'm on 3" and have no issue moving up another inch.

The weight issue up front could (I'd assume) be taken care of with a good set of coilovers.

I'm hearing now from JJY that you need to run radius control arms up front. I am not familiar with radius arms much and not sure what to think of that. I need a good pic to see where the stock front upper control arm mounts are. I'm wondering if the Poly Performance long arms would move them out far enough to make room.

If JJY is really getting 26 city/30 highway with 40's on 5.13's, then 38's on 4.10's or 40's on 4.56's should get even better! That being said, I'm thinking you'd want a little more gearing offroad then 'cause the 4.10/4.56's with the 3.08 or so first gear of that 700R4 wouldn't make for a very low crawl ratio. Nothing an Atlas 6.0 and/or Klune Goliath couldn't fix.

Now, have you been reading?

Atlas
Klune
Coilovers
Long arms
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Heck, I'm up over $10k before I even start the swap.

I still wanna do it though.

Call me crazy.
 

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I'd love to do the diesel swap over to the 4bt. Absolutely love it... but I don't see it happening any time soon. First big hurdle is the state. Its doubtful that it'll pass emissions, and even if it does I'm sure that the Commonwealth of mASSachusetts has something up its sleeve to fawk up those plans. After that its all sort of moot as my jeep is still an everyday driver. :shaking:
 

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If you want to tow the diesel is a great option

Other than that a gas v8 is going to be way way way more fun in every way. Some Diesels have that monster tq we all love, however off road a nice revving v8 is where its at.

Around town it's the same thing.

IMHO a crd diesel swap is overrated... A cummins would be cool.., But a fun 400+ hp gasser is where it's at.
 

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I voted both. You meant the 4bt and bacon, right???
:thefinger:


IMO
I am going 4bt ASAP, because I HATE the 3.8... I had treated it right, and it decided to leave me in the mud. My first one had every oil change on time, and all services that needed to be done were performed by myself or a certified tech (if I wasn't able). There was no reason for there to be mud inside when all openings were still dry... I could tell there wasn't mud in the tailpipe/muffle when I removed it after. It is a crappy engine for the application. It was, and still is, a great engine in a 2wd configuration, but mating to a t.case wreaks havoc on it. This opinion of mine is shared with my mechanic whos shop has been around since the mid '70s.

Yes, now I treat the engine like shit, but that is because I know it is.
 

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When the 3.8 goes 4bt all the way. Actually will start modding the suspension for this soon. The BB works for me now but RC is in the wings. I just love this conversion and am starting to save for it now... same money situation as u larry. But if and when this motor pops... and it will be backed up with an atlas 2.:beer::beer::beer:
 

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Discussion Starter · #16 · (Edited)
When the 3.8 goes 4bt all the way. Actually will start modding the suspension for this soon. The BB works for me now but RC is in the wings. I just love this conversion and am starting to save for it now... same money situation as u larry. But if and when this motor pops... and it will be backed up with an atlas 2.:beer::beer::beer:
This is kinda what I had in mind too, adjust the mod list to accommodate the 4BT and only do the one's that are in line with it. I'm trying not to back track monetarily speaking. It's also why I have held out on a series of interior mods as I'm still waiting on PSC's full 4dr cage.

I guess I should also throw out there that I realize some of you have your rigs as play toys and not DD's. I think thats why I'm all for this; because it is my DD, to be able to get better MPG even with in-town driving is just a bit more important to me than just it's off-road capability. I haven't been in a hurry to do all the usual mods simply cause I'm enjoying the challenge a stocker provides versus throwing a bunch of $$$ at it and suddenly being able to walk over every obstacle I come across. Besides it's not like I live in Colorado or Moab....:laughing:

I've also always had an expedition vehicle in mind with my mod list, so getting better fuel economy = more time off-road and less looking for a fuel station.

I also remember how many people would chime in on every Hemi thread about wanting the diesel over the V8, so some of the responses kind of surprises me while others make valied arguments...:beer::beer:
 

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what tranny/gears are you 4bt guys planning on running? keep in mind how low the redline is on that motor
 

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I'm pretty much sold on a 4bt too when my 3.8 is shot. By that time it won't be a DD anymore, which will be a plus.
 

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I'm with you on this. A diesel is definately on my list. And after talking to Jeff, the list just might have become much shorter.
His attention to detail and wanting to make sure everything is done right is what has me sold on him.
Is this for everybody? no.
BUT, for me, the long term is what I'm looking at. My Jeep has 108k on it. I'm on my 2nd motor.
The 4BT can get 300k or more before a rebuild. A rebuild kit costs about $700 and can easily be done in a weekend.
As far as fuel efficiency, The 4BT will get approx twice the mileage that I am getting now.
Gas here is 3.69. Diesel is 3.99. Diesel would have to reach almost $8 a gallon before I would be at a loss. It doesn't take a genius to figure out that it is more bang for the buck on a day to day basis.
4BT conversions have been done for years in all types of vehicles, so they have a proven track record. Lets be honest, they wouldn't be in bread trucks and delivery vehicles if they weren't reliable.
The down side... It will definately be alot louder. For alot of people, this may be an issue. I can understand that. Me, If you heard the noise from my tires, you would be begging for another sound to drown that out.
All in all, I realize that it's not for everyone, but I think it is definately for me.
 
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