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-   -   4bt vs 350 (http://www.wranglerforum.com/f210/4bt-vs-350-a-254280.html)

HeyImWade 07-07-2013 09:03 PM

4bt vs 350
 
So I wanna do an engine swap sometime in the future and I'm wondering if I should do a 4bt or a 350. I'm just asking for your opinion or what you think would be a better engine to put in a TJ.

cbush1885 07-07-2013 09:13 PM

just preference, but i would go with the 350 only because i know gas engines better then diesel

UnlimitedRubicon 07-08-2013 03:59 AM

LS engine without a doubt

Bronek 07-08-2013 04:11 AM

If those are the only options, go with the 350. Diesel isn't practical on a trail rig.

Bravo.Justin 07-08-2013 04:33 AM

Can't beat the torque of a diesel tho. Banks makes a crate diesel for the tj now. Same one the 2014 Grand Cherokee will be toting.

MississippiDirtTJ 07-08-2013 06:29 AM

Quote:

Originally Posted by Bravo.Justin (Post 3937645)
Can't beat the torque of a diesel tho. Banks makes a crate diesel for the tj now. Same one the 2014 Grand Cherokee will be toting.

I can't find anything pertaining to this on google. Care to share a link for to help enlighten the rest of us?

lindel 07-08-2013 07:13 AM

Quote:

Originally Posted by Bronek (Post 3937630)
If those are the only options, go with the 350. Diesel isn't practical on a trail rig.

Why wouldn't a diesel be a good option? You don't need high rpms, you want more torque, and better efficiency would be a plus.

Rubicondon53 07-08-2013 07:21 AM

LS all the way,,, if you insist on an oil burner, then the BT... The new diesels are seriously flawed... I had one of those Motori motors in a Liberty, at 93,000, catastrophic failure of the fuel delivery system, the Bosch high pressure pump went out, and took the entire fuel rail with it,,, $5,000 later we got it back on the road, sold it, and bought my wife a VW gasser... I'll never use a "modern" diesel ever again... The 4Bt, is simple old fashioned, tech, and extraordinarily dependable for at least a half million miles.... Just my 2 cent ;)

Imped 07-08-2013 08:04 AM

Do you want a lightweight gas engine or a heavy diesel engine?

It's really that simple.

Bravo.Justin 07-08-2013 06:36 PM

Quote:

Originally Posted by MississippiDirtTJ (Post 3937730)

I can't find anything pertaining to this on google. Care to share a link for to help enlighten the rest of us?

I read it yesterday in 4 Wheel Drive magazine. It's a 3.0L 182ci V6 if I remember correctly. Same mill as the Grand Cherokee. Let me find the article...

Bravo.Justin 07-08-2013 06:40 PM

1 Attachment(s)
Yup, knew I wasn't that crazy yet

HillbillyJeeper 07-08-2013 06:46 PM

If you go diesel your gonna have to think front springs and shoks too, might be OK overtime, and if you aint off road much. but hard wheelin that extra weight might be a factor. I'm still a diesel fan tho.

McDaniel274 07-08-2013 07:12 PM

I currently run a 4bt in my 03 Tj it's been very practical for me so far 24mpg w/ 4in lift on 33's and its my daily driver but weight wise the difference between a LS1 and 4bt is around 250lb and I have a heavy front bumper and winch on the front and the coils and shocks aren't any different holds up no problem even under interstate speeds and its a cummins they run forever

McDaniel274 07-08-2013 07:19 PM

1 Attachment(s)
And it looks like it belongs in there as well haha

jmcc75 07-08-2013 10:11 PM

That's sexy

NCJeepin 07-08-2013 10:44 PM

Quote:

Originally Posted by McDaniel274 (Post 3939854)
And it looks like it belongs in there as well haha

Man that's clean. Looks great. Definitely go 4bt. Perfect for offroad with gobs of torque (you don't need the high rpm horsepower offroad). Plus you will have plenty of power on road with good, well better mpgs. Not to mention the reliability of the Cummins. I plan to do the 4bt swap in the future after school.

Rubicondon53 07-09-2013 06:03 AM

I'm curious, as I stated before, the 4bt is the only diesel swap I would consider, how long ago did you do the swap? Did you retain the jeep transmission? And what gears are you running, 3:07s? If you have 3:07s you should be very comfortable cruising at 70 mph at around 1600 rpms. While cruising at highway speeds does it smooth out nicely? I've considered this swap instead of buying a new rubicon in the future but haven't found anyone willing to talk about how well it works for long range travel, ie, exploring North America, from the Rockies to the Yukon and on up into Alaska.... Retirement is around the corner and we plan on long range extended trips.. 24 mpg is a lot better than 12 to 14 mpg which is what we currently get with our 4.0, loaded with gear and pulling the trailer... The 4bt wouldn't even sneeze at the extra weight... ;). Nice job !!

caryt 07-09-2013 09:22 AM

Any fuel injected gas motor is better than a sticking diesel on a trail. I go to enjoy the outdoors not smell diesel fumes. Diesels are great on asphalt where they belong.

SAABseanSCANIA 07-09-2013 09:54 AM

Quote:

Originally Posted by Rubicondon53 (Post 3937810)
LS all the way,,, if you insist on an oil burner, then the BT... The new diesels are seriously flawed... I had one of those Motori motors in a Liberty, at 93,000, catastrophic failure of the fuel delivery system, the Bosch high pressure pump went out, and took the entire fuel rail with it,,, $5,000 later we got it back on the road, sold it, and bought my wife a VW gasser... I'll never use a "modern" diesel ever again... The 4Bt, is simple old fashioned, tech, and extraordinarily dependable for at least a half million miles.... Just my 2 cent ;)

Well, I have to chime in on a diesel topic....

I'd agree (formerly having to be cummins/CAT certified) that the old cummins would be the way to go for simplicity if you've been bitten by the diesel bug; and if you're buying a true mechanical B series engine. The great thing about these old engines is they're mechanical; the fuel system is a mechanically driven, mechanically timed, rotary vane pump or inline cam driven (translation: cheap rebuild). I get a giggle every time I hear a RAM guy say he has a 6BT in his 98+ 2500..... because it's not; it's electronically controlled Bosch as they all are (whether common rail or not). If you plan on getting an ISB (after 97), plan on dealing with unit injection. But with a mechanical engine in mind, you might have to adjust valve lash and you WILL (and I mean that) be rebuilding pumps; but it's cheaper to rebuild at intervals than replace at failure, that's why they're useable service life is about 350K before complete overhaul (500K is optimistic but possible) .

Don't get me wrong, the electronics aren't necessarily BAD; and I don't think the system is realistically "flawed" as almost every new vehicle with an internal combustion engine is HP common rail nowadays. The VM Motori you had in the liberty has a "modern" system in the sense that the unit injectors are controlled by a computer and the fuel delivery is under high pressure in a "common rail" (which your VW gasser is as well by the way). In your case, you had a Bosch CP3 Pump. Within this unit there are a couple components. It has a lift pump attached to the rear of the HP housing that draws the fuel to the HP Pump. What this does is supply fuel and keep the HP Pump lubricated (aka feed the pump). In between there is a regulating valve that controls pump lubrication, fuel supply to another valve, and acts to return fuel to the tank. On top of that, there is a fuel quantity valve that controls the amount of fuel heading into the HP pump (metering). Finally the HP side of the pump supplies rail pressure. Lot going on in there huh? But, the Bosch CP3 is used in all modern Cummins and Dmax engines, so "flawed" wouldn't be the word for a single point failure. With 93K miles I'm assuming that no fuel pressure high/low test was performed prior to the failure? I don't own a CRD so I'm not sure what the dealers do as far as service, but with a modern diesel it's either buy the equipment to do it yourself or cough up the money for a shop to do it. My guess is either the valving failed or the lift pump failed; both cause the HP pump to lean out and fail. But this is the technological world we live in with fuel economy and emissions to worry about. The benefit to having an electronically controlled system is controlling fuel volume, exhaust temps, engine speed, and emissions (all very important when trying to market a highway capable Jeep Liberty that gets "great" fuel economy). So an electrically controlled fuel system isn't necessarily "flawed" per se, but it's certainly not as simple as a mechanical system and with symbiotic components there's bound to be failures (VW diesels are unfortunately experiencing a bad rep for their fuel systems as well).

That's my .02 anyways. I'd love to run an old 4BT in mine for pure novelty but the cost outweighs the "joy" I personally would get from it. I also don't think weight is an issue because plenty of gents on here have done the swap and they're riding just fine, so I imagine they've mastered the issue.

Rubicondon53 07-09-2013 10:06 AM

Quote:

Originally Posted by caryt (Post 3942004)
Any fuel injected gas motor is better than a sticking diesel on a trail. I go to enjoy the outdoors not smell diesel fumes. Diesels are great on asphalt where they belong.

Sadly, you are mis-informed beyond reasonable belief.. A well tuned ( dyno-tuned ) diesel, even the older Diesel engines, do NOT smell of diesel. . New diesel technology are extraordinarily clean.. Bio diesel, smells a little like french fries, and emit 0 emissions..... If I ever make the swap, I'd be burning a lot of emission free veggie oil... Can't say that about a gasser :)

Rubicondon53 07-09-2013 10:39 AM

Quote:

Originally Posted by SAABseanSCANIA (Post 3942107)

Well, I have to chime in on a diesel topic....

I'd agree (formerly having to be cummins/CAT certified) that the old cummins would be the way to go for simplicity if you've been bitten by the diesel bug; and if you're buying a true mechanical B series engine. The great thing about these old engines is they're mechanical; the fuel system is a mechanically driven, mechanically timed, rotary vane pump or inline cam driven (translation: cheap rebuild). I get a giggle every time I hear a RAM guy say he has a 6BT in his 98+ 2500..... because it's not; it's electronically controlled Bosch as they all are (whether common rail or not). If you plan on getting an ISB (after 97), plan on dealing with unit injection. But with a mechanical engine in mind, you might have to adjust valve lash and you WILL (and I mean that) be rebuilding pumps; but it's cheaper to rebuild at intervals than replace at failure, that's why they're useable service life is about 350K before complete overhaul (500K is optimistic but possible) .

Don't get me wrong, the electronics aren't necessarily BAD; and I don't think the system is realistically "flawed" as almost every new vehicle with an internal combustion engine is HP common rail nowadays. The VM Motori you had in the liberty has a "modern" system in the sense that the unit injectors are controlled by a computer and the fuel delivery is under high pressure in a "common rail" (which your VW gasser is as well by the way). In your case, you had a Bosch CP3 Pump. Within this unit there are a couple components. It has a lift pump attached to the rear of the HP housing that draws the fuel to the HP Pump. What this does is supply fuel and keep the HP Pump lubricated (aka feed the pump). In between there is a regulating valve that controls pump lubrication, fuel supply to another valve, and acts to return fuel to the tank. On top of that, there is a fuel quantity valve that controls the amount of fuel heading into the HP pump (metering). Finally the HP side of the pump supplies rail pressure. Lot going on in there huh? But, the Bosch CP3 is used in all modern Cummins and Dmax engines, so "flawed" wouldn't be the word for a single point failure. With 93K miles I'm assuming that no fuel pressure high/low test was performed prior to the failure? I don't own a CRD so I'm not sure what the dealers do as far as service, but with a modern diesel it's either buy the equipment to do it yourself or cough up the money for a shop to do it. My guess is either the valving failed or the lift pump failed; both cause the HP pump to lean out and fail. But this is the technological world we live in with fuel economy and emissions to worry about. The benefit to having an electronically controlled system is controlling fuel volume, exhaust temps, engine speed, and emissions (all very important when trying to market a highway capable Jeep Liberty that gets "great" fuel economy). So an electrically controlled fuel system isn't necessarily "flawed" per se, but it's certainly not as simple as a mechanical system and with symbiotic components there's bound to be failures (VW diesels are unfortunately experiencing a bad rep for their fuel systems as well).

That's my .02 anyways. I'd love to run an old 4BT in mine for pure novelty but the cost outweighs the "joy" I personally would get from it. I also don't think weight is an issue because plenty of gents on here have done the swap and they're riding just fine, so I imagine they've mastered the issue.

Agreed,,, I learned about everything you wrote on the way there... It isn't necessarily the CP3's fault that it suffered from lack of lube... Chrysler went on the cheap utilizing too many components from a gasser unit,, ie, rubber fuel lines, weak connectors, bad filter head with hearing unit. etc,,, the biggest flaw was the lack of a lifter pump.. The dealership never succeeded in getting the fuel bubble free, which I discovered when installing a new filter at 40,000 miles... I have theorized that the constant flow of air bubbles, caused by small leaks, and the lack of a lifter pump, caused the early demise of the CP3... I'm over it now, but at the time I was very upset that Chrysler off handedly dismissed my logic and refused to help with the repair bill.. You are obviously much better versed on the subject, is theory wrong?

NJO 07-09-2013 10:45 AM

426 Hemi and don't look back.

wrangler0232 07-09-2013 10:46 AM

I would say 4bt get the torque I was thinking that if I chose to go diesel or a 5.7 hemi:punk:

SAABseanSCANIA 07-09-2013 10:47 AM

Quote:

Originally Posted by Rubicondon53 (Post 3942141)
Sadly, you are mis-informed beyond reasonable belief.. A well tuned ( dyno-tuned ) diesel, even the older Diesel engines, do NOT smell of diesel. . New diesel technology are extraordinarily clean.. Bio diesel, smells a little like french fries, and emit 0 emissions..... If I ever make the swap, I'd be burning a lot of emission free veggie oil... Can't say that about a gasser :)

100% correct. I think he's seen too many kids with Powerstrokes blowing black smoke all over the place because they think turning their injection pumps up is "cool".

A proper running diesel is actually cleaner than a gasoline engine in theory. Noisier? Sometimes. Dirtier? Not necessarily. They are also more efficient and the fuel is less dangerous to transport than gasoline in the event of an accident; which is why ground force tactical vehicles aren't gasoline.........gas engines have a heck of a time burning JP-8 :thumb:

McDaniel274 07-09-2013 10:26 PM

Quote:

Originally Posted by Rubicondon53 (Post 3941521)
I'm curious, as I stated before, the 4bt is the only diesel swap I would consider, how long ago did you do the swap? Did you retain the jeep transmission? And what gears are you running, 3:07s? If you have 3:07s you should be very comfortable cruising at 70 mph at around 1600 rpms. While cruising at highway speeds does it smooth out nicely? I've considered this swap instead of buying a new rubicon in the future but haven't found anyone willing to talk about how well it works for long range travel, ie, exploring North America, from the Rockies to the Yukon and on up into Alaska.... Retirement is around the corner and we plan on long range extended trips.. 24 mpg is a lot better than 12 to 14 mpg which is what we currently get with our 4.0, loaded with gear and pulling the trailer... The 4bt wouldn't even sneeze at the extra weight... ;). Nice job !!

"Simplicity is the key to longevity" - I want to trademark that quote haha but crazy luck is why I'm driving it today. I started out looking to buy TJ, one with low miles no lift, no abuse. My dream was to build what I drive today. I started out looking for build sheets other forums and "running" the numbers of what it would cost to build a Tj with a 4bt conversion. Some how I stumbled upon this jeep on a 4btswaps.com forum and the guy had a buildsheet of everything ever done to it. This was going to be my "blueprints of what I wanted to build". And by sheer luck I stumble upon this same jeep forsale. I jumped on the chance to purchase it I only have 12g for and 03 jeep with everything you see on it now and the owner was only a 100miles away from me. Like I said sheer luck haha

Now for the jeep 03 TJ 3.9l 4bt cummins turbo mechanical VE pump with gm clutch and bell housing transmission NV3550 and np231 and Dana 30-35 axles @ 3.07s the jeep I have nearly 20,000 on it since I've owned it I commute nearly 400-500 a week in it between school and work pumped is turned up with predator injectors was on the dyno at one point and put out 250hp and around 450ft/lb everything is mechanical, the Tj is as simple as simple gets, only break down has been front seal went out on pinion bearing on the rear axle. And theres no vacuum pump on the engine so you have to run a hydro-boost system for the brakes and you lose your vent controls. But a simple 12volt vacuum pump can easily fix that vent. Do i plan on building everything up i.e NV4550, atlas, dana 44's, etc. I will replace the old as they go. Does it smoke, yes, does it smell like diesel, yes, but do I care not one bit. Watching that boost gauge being pinned at 40lbs and rear tires chirping and leaving a subtle cloud behind doesn't happen everyday in jeep

Lando25 07-09-2013 10:54 PM

Quote:

Originally Posted by caryt (Post 3942004)
Any fuel injected gas motor is better than a sticking diesel on a trail. I go to enjoy the outdoors not smell diesel fumes. Diesels are great on asphalt where they belong.

As others have said diesels overall are clean and very efficient. They have a bad stigma from 16 year olds chipping their dads truck so the injectors pour too much fuel causing it to smoke. The diesel in my 82 Monte Carlo is cleaner and far more efficient than anything that was offered back the. The same holds true today.

caryt 07-10-2013 09:41 AM

Then you guys get stuck behind one...no diesel will smell as clean as a fuel injected small block..besides the OP was asking about a 4bt

NCJeepin 07-10-2013 10:14 AM

Am I the only one in here that thinks diesel smells good??:confused:

Lando25 07-10-2013 11:14 AM

Quote:

Originally Posted by "caryt (Post 3946100)
besides the OP was asking about a 4bt

Cummins 4bt is a diesel.

brandon-99tj 07-10-2013 11:49 AM

Quote:

Originally Posted by NCJeepin (Post 3946217)
Am I the only one in here that thinks diesel smells good??:confused:

Nope. I love the smell of diesel:)


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