I have been researching the new 4 BT conversion for my JK

[DesertJK]

I am really liking what I see and hear about this conversion. Even with the negative stuff I have heard about the 4 BT being loud and vibration prone I still like the conversion. I have looked around a little for infor on the 16 valve Cummins but it seems they are not imported to the USA and it may be better to just go with a 4 BT.
With a NV 5600 (6 speed manual) trans, Jeffs Jeep Yard (the guys who make the kit) claim I shuld get almost 30 MPG with my tire and gearing combo, 20 pulling my trailer. I would be fine with 15 with the trailer if I had power that matched the fuel burn.

From what I have read, the 4 BT can be a pretty smooth engine with balancing. I have also read that 300,000 miles in medium duty is the expected life span.

I can't do this until I pay the Jeep off (about 8 months) and I would make a trip down to Florida to drive one of thier conversions before buying in excess of $10K in parts for my Jeep.

I like my Wrangler, and I have looked for something else I like with a better engine, but there is nothing out there that intrests me. I suppose if the was Diesel Toyota trucks that could pull 5000 pounds, but were simular in size to the Jeep, I would want to take a look, or maybe a diesel Dodge Dakota or the like.

Anyone want to disscuss this further?

D.

 

[DesertJK]

A link

http://www.dieselbruiser.com/

 

[DesertJK]

 

[JPK]

You might want to look into conversions or kits from River Raiders Off Road. Don't know much about what they're doing with the diesels but they sure make good quality stuff.

Personally, I wouldn't do a diesel conversion. There is no way to make it legal since federal regs require the donor engine to burn the same fuel as the oem engine, and to be from the same class of vehicle too, as well as from the oem year of production or later.

I did have a Hemi conversion done, and couldn't be happier with the results. However, if the Pentastar, WA 580 auto trans and 4.10 gears (and 4:1 transfer case) combo had been available when I did my conversion I would have saved the $'s. had been you haven't tried the new 2012 Jeeps, especially one with the auto and with 4.10's you really ought to. It may solve your issues.

BTW, Hemi mileage is about 16mpg across country, 12.9 all around, 9 off road mostly in 4 lo. With the 18gal auxilliary tank in my JKU range is not an issue. With the Hemi, power is not an issue.

 

[shortbus4x4]

Would you even be able to register in WA after the diesel conversion due to state smog laws. It won't be legal Federally but the Feds don't have a smog check program yet so you could squeak by there. It has to do with the 4bt being for a heavy duty chassis and your Jeep being a light duty chassis, you can't marry the two. Some of the newer Fedex trucks and such have the 16 valve cummins in them, they aren't real common or cheap.

 

[Dan Grec]

I'm one of the biggest diesel advocates getting around, and I don't want to be a negative nelly, but in all honesty a 4BT would be the absolute bottom of my list for a conversion.

By very definition this is an extremely old design - I personally don't think you gain enough.

The 4BT is loud, vibrates a lot, sluggish and doesn't actually get great mileage*
(Sure, more than gas, but not good for sophisticated diesels.)

In my humble opinion, in the year 2012, I wouldn't spend all that money on something that doesn't have DOHC, VVT, 4 valves a cylinder, etc. etc.
A new, sophisticated diesel should get you right up to 30MPG, AND be smooth a silk.
Lets face it, you're talking about driving a vehicle with cruise control, sat nav, power windows, etc. etc. and you want to put a horribly old clunky engine in it.

I personally think the 4BT is the personification of everything the public hates and fears about diesels.

If you have the money, and really want a diesel, I'd be talking to AEV about a VM 2.8 - They clearly have the know-how (Dave did a conversion in his own personal JK)

Just my 2c

-Dan

 

[DesertJK]

You might want to look into conversions or kits from River Raiders Off Road. Don't know much about what they're doing with the diesels but they sure make good quality stuff.

Personally, I wouldn't do a diesel conversion. There is no way to make it legal since federal regs require the donor engine to burn the same fuel as the oem engine, and to be from the same class of vehicle too, as well as from the oem year of production or later.

I did have a Hemi conversion done, and couldn't be happier with the results. However, if the Pentastar, WA 580 auto trans and 4.10 gears (and 4:1 transfer case) combo had been available when I did my conversion I would have saved the $'s. had been you haven't tried the new 2012 Jeeps, especially one with the auto and with 4.10's you really ought to. It may solve your issues.

BTW, Hemi mileage is about 16mpg across country, 12.9 all around, 9 off road mostly in 4 lo. With the 18gal auxilliary tank in my JKU range is not an issue. With the Hemi, power is not an issue.

A hemi is a possibility, as is the Ripp Supercharger. This is the same kit as the Ruged Ridge.

 

[DesertJK]

Hmm, steal a Fed Ex truck......

I live way out in rural Washington and we are not going to have testing here any time soon. I have never heard of spot check by state patrol, so I will be fine.

 

[DesertJK]

I'm one of the biggest diesel advocates getting around, and I don't want to be a negative nelly, but in all honesty a 4BT would be the absolute bottom of my list for a conversion.

By very definition this is an extremely old design - I personally don't think you gain enough.

The 4BT is loud, vibrates a lot, sluggish and doesn't actually get great mileage*
(Sure, more than gas, but not good for sophisticated diesels.)

In my humble opinion, in the year 2012, I wouldn't spend all that money on something that doesn't have DOHC, VVT, 4 valves a cylinder, etc. etc.
A new, sophisticated diesel should get you right up to 30MPG, AND be smooth a silk.
Lets face it, you're talking about driving a vehicle with cruise control, sat nav, power windows, etc. etc. and you want to put a horribly old clunky engine in it.

I personally think the 4BT is the personification of everything the public hates and fears about diesels.

If you have the money, and really want a diesel, I'd be talking to AEV about a VM 2.8 - They clearly have the know-how (Dave did a conversion in his own personal JK)

Just my 2c

-Dan

The VM 2.8 is not great. I would just go with a Hemi. I agree with you about the 4 BT as far as deign but I have no first hand experience with them. The new 16 Valve would be the way to go, but I have yet to find one for sale in the USA.

 

[SulVento]

You might want to look into conversions or kits from River Raiders Off Road. Don't know much about what they're doing with the diesels but they sure make good quality stuff.

River Raider is working in conjunction with Jeff's Jeep Yard I believe.....

Some reference threads here:

Jeep Yard 4bt Conversions

JK Wrangler 4BT Diesel Conversion


I love the idea and can envision it in my future mods......but it's a bit down on the list at the moment....

 

[owhiting]

4bt

I have done a couple diesel engine conversions in Land Rovers. I know it's not the same but just thought I would throw in my 2 cents. The 4 bt will go 300,000, the stock engine in your jeep will do that if you take good care of it. Diesel fuel is roughly 40 cents more per gallon and the cost of the conversion will never pay for its self. The 4bt is rough and loud and I am a diesel technician from way back and have worked on many cummins engines, but I think it would drive me crazy in a jeep. There is no amount of sound proofing that will help but maybe I am just getting softer with age.

Here in the U.S. there really aren't any good options for light weight high speed diesel engine conversions.



You can poke up the power in your JK with a supercharger.

Oliver

 

[shortbus4x4]

With diesel costing more than gas now you will have to drive alot of miles to even break even on the cost of the conversion. Go on 4btswaps.com and do some research on your idea. Its going to cost you lots of money, lots of money. There is a 3.9 ISB for sale in Milton-Freewater OR on 4btswaps classifieds right now, its a 16 valve common rail 4 cylinder electronic modern diesel engine. I have a diesel Jeep PU, nothing that Jeep ever put together though.:coffeedrink: Its a 67 M715 with a 4bt swapped in.

 

[JPK]

Perhaps the Mercedes 6 cylinder from the prior Grand Cherokees? Smooth, quiet, nice package.

Or wait until the new 6 cylinder comes out in 2013 or 2014?

 

[reece146]

Paying 40% more at the pump to go 30% farther while paying $5,000 - $15,000 for the privelege of doing so really doesn't make a lot of sense.

You are better off focusing on building efficiency in the vehicle you have, saying the hell with it and building for power because it's fun or switching platforms entirely.

2¢

 

[DesertJK]

Everytime I start thinking engine swap in my Jeep, the issues that come up are:

1. It has plenty of power for any normal offroad use.

2. There are better vehicles to tow my trailer with that are good enough of road for the type of expo travel I do. The price of converting the Jeep is a very healthy down payment on several choices

3. There are tons of car I really like (Audi, Mini, Fiat) that get great mileage and can be bought use for just a little more than converting the Jeep to something it is not.

4. If I had three cars (plenty of room to park at my house) instead of one that my wife and I share, I would put less miles on each and therefore each would last me longer.

There you go, I talked myself out of a conversion. Maybe if I have some extra cash at the end of this summer I get a Ripp Supercharger, but for the $5000 I could also get a new enduro or maybe a sled, or 100 hours worth of airplane fuel.