4bt motor swap in a 2008 Jeep JKUR

[corbin.black]

Says off road use only on bruiser conversions web site right under their price.

do you believe everything you read on the Internet?

Your're right. An 80's Sierra is very similar to an 08 JK. Well at least they both have an 8 in their model year.

It doesn't make a bit of difference who does the inspection, or how much you pay them. If it's not legal and you run it, any cop that knows better can have it towed away. What would you do then? You have how much money tied up in a jeep that is worthless.

woah, I must have missed where I said they were similar at all. I was just saying that the Sierra is 100% legal to drive and that I was curious what made the Jk swap illegal. I never said the jeep swap was legal because I don't know if it is or not. I'm just curious

 

[spencevans]

I don't remember all the details but I sure some one will chime in. IIRC to make it a legal swap you must use an engine from a vehicle with an equal or newer model year to make it a legal swap. The 4BT does not qualify because of its age and it was never offered in a passenger vehicle. There are some exclusions for vehicles that are over 15 years old but an '08 JK would not be eligible for those exclusions. If you are looking to stuff a diesel in an '08 JK the best bet may be the 3.0L Mercedes Bluetec from an '08 Jeep Grand Cherokee. It would be street legal and it may be a pretty straight forward swap.

 

[jeep-N-montero]

As was mentioned, from previous research the engine has to be newer than the chassis and also to have been a factory option in their product line.

 

[UNSTUCK]

I would just call the station that will inspect it once the swap is done. Everyone seems to have a different story on what the rules are. I know that my cj7 passed just fine with a chevy TPI in it. The same motor that Stratton passed in his YJ. Not factory options.

 

[ERICON18]

well for starters, thank you for all the input. As for emissions have a good friendthat has been doing safety and emissions test for several years, he says there's nothing illegal about this Swap.I also have 2 very close friends are diesel mechanics that are averaging 35 to 40 mpg's in full size rigs. I'm confident that I can muster up every ounce of power this this motor has to offer. gas motors last 300k miles (if your good to them). diesel last half million easy! as for vibration and noise I've grown up around heavy equipment 4BT is nothing lol, and when your tops off you can't hear anything anyways haha

 

[Greg]

Gotta say it... 35-40 MPG average out of a 4BT is unrealistic. Mid to high 20's is much more within reason.

Real world #'s - http://www.4btswaps.com/forum/showthread.php?6254-Fuel-Log

 

[MikeGyver]

Ive said it before... realistically, a 4BT swap is so unappealing that I just don't understand the obsession with them.
Put up against a typical LS style V8, it pales in comparison in every. single. criteria.

 

[Greg]

Ive said it before... realistically, a 4BT swap is so unappealing that I just don't understand the obsession with them.
Put up against a typical LS style V8, it pales in comparison in every. single. criteria.

Yes, but to someone that's a diesel fanatic, a LS-based engine is just another gasoline powered POS.

I'll admit that I'm a diesel fan myself... 4BT's are commonly available, lots of 6BT upgrades apply and the 6BT has had damn near everything done to it, so there's a lot of info out there that also applies to 4BT's. Comparing an LQ4 to a 4BT... sure they can put out similar torque with a few mods, but the 4BT will double the mileage.... not to mention the amount of torque off idle. And most anyone with a big 4x4 would love to have 2x the MPG's and massive torque off idle.

Dollar for dollar, I'm sure it's cheaper to swap in a LSx engine versus a 4BT. When you consider cost, weight, noise, size... it's hard to justify a 4BT. On the other hand, 4BT's are pretty simple when it comes to the wiring.

 

[ERICON18]

Gotta say it... 35-40 MPG average out of a 4BT is unrealistic. Mid to high 20's is much more within reason.

Real world #'s - http://www.4btswaps.com/forum/showthread.php?6254-Fuel-Log

They are averaging 35-40 out of 24v common rail. But mid to high twentys is much better than the 14 that I'm getting now. Plus the added torque, and motor reliability...

 

[Cascadia]

But does the fuel savings even equal out to how much the swap costs? Is it worth it in the end? And will you really ever keep the jk for 500k miles?

 

[flexyfool]

I saw a 4bt in an early Bronco. It was not stupid loud nor did it vibrate excessively.

Passing a visual inspection and an actual tailpipe test seems problematic. It is a huge step backwards in smog control. I know nothing about Utah's regulations though. The resale value may be lower than the stock V6 and certainly lower than any V8 swap. The resale market for such a thing is very small.

How about a Chrysler PowerTech 4.7L V8? It would be much cheaper than a "Hemi" or Chevy LS. 10x cheaper? It should have compatible electronics.

http://en.wikipedia.org/wiki/Chrysler_PowerTech_engine:

"The 4.7-liter version was the first of this family, appearing in the 1999 Jeep Grand Cherokee. The displacement is 287 cubic inches (4698 cc) with a bore of 3.66 in (93 mm) and a stroke of 3.405 in (86.5 mm). It has a cast iron block and aluminum heads with two valves per cylinder. It uses chain-drivenoverhead camshafts, one in each head. It originally produced 235 hp (175 kW) and 295 lb·ft (400 N·m) oftorque. The 2012 4.7L has 2 valves and 2 spark plugs per cylinder and puts out 310 hp (230 kW) and 330 lb·ft (450 N·m). Dodge has claimed that it has increased compression ratio and improved cylinder head port flow, the 4.7 L V8 is available with four speed and five speed automatic transmissions.
The PowerTech was on the Ward's 10 Best Engines list for 1999.
Applications:

• 1999–2009 Jeep Grand Cherokee
• 2000–2011 Dodge Dakota
• 2000–2009 Dodge Durango
• 2002–2013 Dodge Ram 1500
• 2006–2009 Jeep Commander
• 2007–2009 Chrysler Aspen"

 

[bryson]

Only problem with the 4.7 swap is the 4.7 - At least the earlier 99-04(?) versions. It isn't even a little uncommon to find them blown up (or close to it) due to head gasket issues. The later ones may be better. If the head gasket issues have been/can be fixed, it could be a neat engine, but the HP/torque #'s aren't that much different than a stock JK.

 

[flexyfool]

Best of the years appears to be '08+.

[h=3]4.7 HO/Magnum[edit][/h]A "High-Output" version of the 4.7 L PowerTech engine, producing 265 hp (198 kW) and 330 lb·ft (450 N·m) of torque, was introduced in 2002, first appearing in the Jeep Grand Cherokee Overland.
This engine was discontinued after the 2007 model year, though the non high output 4.7L V8 engine continued to be available in all vehicles.
Applications:

• 2002–2004 Jeep Grand Cherokee
• 2002–2007 Dodge Dakota
• 2002–2013 Dodge Ram 1500
• 2006–2007 Mitsubishi Raider

[h=3]2008 Revisions[edit][/h]The 2008 Dodge Dakota and Ram pickup trucks, Dodge Durango and Chrysler Aspen SUV's, Jeep Grand Cherokee, and Jeep Commander came with a Corsair version of the FFV 4.7 L engine, with dual spark plugs per cylinder, a new slant / squish combustion system design, and 9.8:1 compression, raising power to 290–310 hp (220–230 kW) and 320–334 lb·ft (434–453 N·m) of torque. See Allpar's page on the latest 4.7 L.

 

[ChestonScout]

when the 345 goes out in my 72 Scout Im 90% sure Im gonna put a 4bt in it. Fits the vintage, thing is already a rattle trap, its not much heavier than my IH motor and will most likely be a huge power gain. Mid 20 MPGs would trump my 8or 9 right now.

But this rig is registered as a Vintage Vehicle meaning no inspection or emission tests.


Personally for a newer rig I wouldnt consider this swap. Maybe if I had all the parts sitting and collection dust and the motor in Jeep blew up but that would be the only way.



But if you do it.....BUILD THREAD

 

[chans]

I will chime in since my neighbor's father is the one who helped write the SL county emission laws and since you are in Sandy it would be illegal unless you register in a different county. Bottom line it has to be the same year or newer with all the emissions from donor vehicle and once you do the swap it has to be checked by the county so if your buddy passes it and you get caught he will get the fine. How do I know? I am trying to swap a Hilux diesel and getting no love. Definitely need a modern V8 instead or maybe the Mercedes diesel like spencevans mentioned.

 

[rholbrook]

I will chime in since my neighbor's father is the one who helped write the SL county emission laws and since you are in Sandy it would be illegal unless you register in a different county. Bottom line it has to be the same year or newer with all the emissions from donor vehicle and once you do the swap it has to be checked by the county so if your buddy passes it and you get caught he will get the fine. How do I know? I am trying to swap a Hilux diesel and getting no love. Definitely need a modern V8 instead or maybe the Mercedes diesel like spencevans mentioned.

Same with Davis County. I have spent a lot of time across the desk of the 2 main guys at Davis County Emissions.

 

[frieed]

If I could, I would drop the ecoboost v6 and 6-speed slushbox from my current ride into my old (2012) JKU. That would be a sweet setup.
Would probably need better axles under it though, and yes, I am a total ecoboost fanboi...

 

[MikeGyver]

Yes, but to someone that's a diesel fanatic, a LS-based engine is just another gasoline powered POS.

I'll admit that I'm a diesel fan myself... 4BT's are commonly available, lots of 6BT upgrades apply and the 6BT has had damn near everything done to it, so there's a lot of info out there that also applies to 4BT's. Comparing an LQ4 to a 4BT... sure they can put out similar torque with a few mods, but the 4BT will double the mileage.... not to mention the amount of torque off idle. And most anyone with a big 4x4 would love to have 2x the MPG's and massive torque off idle.

Dollar for dollar, I'm sure it's cheaper to swap in a LSx engine versus a 4BT. When you consider cost, weight, noise, size... it's hard to justify a 4BT. On the other hand, 4BT's are pretty simple when it comes to the wiring.

All the swaps listed on that link are like 19mpg avg. Where is this biazrre universal idea coming from that you'll get 30-40mpg avg?
You could get 19mpg with a LS powerplant just by driving as slow as the rig would be with a low hp 4bt.

Tq by itself means absolutely noting. If an engine has half the rpm range, it better have double the tq. I think a stock LS motor actually has more tq off idle at and most definitely across the board than a stock 4bt anyway, and revs to 6krpm so it makes double the power for essentially the same mileage. Double the tq but half the rpm range is exactly the same net effect as doubling your final gearing, it doesn't add performance, power, or mileage (...well maybe crawling performance, since your motor is stuck in low range).
If you accelerated as slowly in the same rig with LS power and appropriate gearing you'd probably get the same mileage. Diesel contains a bit more energy than gasoline, but a new generation gas motor is more efficient in design than an old motor from a breadtruck.

and an LS might actually even be easier to wire up, since there are many swap harnesses that only require you to hook up a couple wires.

 

[flexyfool]

Wow. "Breadtruck motor". What a zinger! True. But wow. Them's fighting words to Cummins fanboys. Now who has a perjorative for the LS motor?

 

[MikeGyver]

I got noting against the motor, it is what it is, I just don't get the obsession and unmerited idolization of it all.