diesel cj3b

diesel cj3b

Dayle

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Location
Cedar Rapids Iowa
Vehicle(s)
1984 CJ7 only mod motorcraft 2bbl no emissions on it after a fire, 195? CJ3B project have not start on it yet
I was wondering if any one on the forum has a cj with a diesel. Stories are the diesel will get any where from 30 to 40 mpg. Sounds to good to be true. Do they run as good as gas at 55/60 mph? What would it take for a conversion? any help? thanks
 
Scout use to put a Nissan diesel in some of their rigs. With out a turbo diesels tend to be more of a tortes than a hare. The other problem with the older diesels is the engine weight. You might try a Scout board and see what some of those guys have to say about a diesel.

Somebody on one of the boards was talking about the new Cummings. In any event it would be a project
 
I was wondering if any one on the forum has a cj with a diesel. Stories are the diesel will get any where from 30 to 40 mpg. Sounds to good to be true. Do they run as good as gas at 55/60 mph? What would it take for a conversion? any help? thanks
My Jeep cj7 is really a hybrid Jeep/Scout with the Nissan Turbo Diesel. It's a heavy engine, 700 lbs, and 101 hp, but torquey. It has a T19 tranny, dana 300 transfer case, dana 44's front and back. Dash was rewired and is custom. The nissan diesel is out there, but they are 31 years old at this point. I'm running 35" tires, and lets face it, mpg is not great with big tires and no aerodynamics.

I've seen the engines on CL, but who knows the condition. I blew first engine (bent something in the bottom half) by driving it at 75 mph on 3.92 gears. The second engine is a bit weaker, and I've no idea the mileage. It was 30 minutes away and $500, so I really couldn't argue. I've installed a tach, as the speedometer is off (shows 55 at 64 mph (per gps)). I think the gas tank/sender is from the scout, because it doesn't match up with the Jeep fuel gauge.

I've read a lot about Jeeps running the 4bt cummins engine, I think they make an adapter plate to get to match the nv5440 trans. I've never seen one.
 
This is something ive kicked around for several years but there doesn't really seem to be a readily available candidate thats cost effective enough to bother with.The frame on a 3b isnt really all that strong and your options are mostly really heavy.

Jeep put perkins 4cyl diesels in cj5's from around 1961-1969.They were expensive and didnt sell well but got about 30mpg.Speed wasn't a strong point but the 4cyl gassers of that era weren't exactly quick either.They were good engines but finding one would be hard and you wouldnt get anywhere quickly.

The renault turbo 4 they used in cherokees in '85-'86 is about the right size and economical but very rare and very unreliable.The nissan sd33 and sd33t[turbocharged] engines weigh as much as a bigblock chevy,arent very powerful or reliable or common and are too long for a '71 or older cj.The toyota 2lt 4cyl turbo diesel would be ideal size wise and give adequate power but they only sold a few in the US and canada in the mid/late '80s and are expensive because the toyota guys want them.

The 2.8 jeep put in libertys is good sizewise and powerwise but only came with auto trans in the US and would be $$$$.The late model turbo 1.9 vw golf engine would be good in a cj3b but $$$$.Both are complicated wiring wise.

The 4bt cummins is a great engine but not a cheap swap.Check out 4btswaps.com for plenty of builds.

About the only fairly cheap, and available diesel swap ive come up with is the not very well liked 6.2 chevy.That would be too big to stick in a cj3b imho,but it doesnt weigh anymore than a sd33 scout engine,bolts up to sbc swap mounts and accepts any chevy transmission.I wouldnt want one in a tow rig but ive been quite happy with them in my '85 blazer and previous '83 suburban.You get 20-24 mpg in a blazer/suburban....unfortunately in a lighter cj7/8 or yj you still only get 20 mpg......which is pretty close to what people get with late model fuel injected v6 and v8 gas swaps and less weight and much better performance.

In the end for me the diesel cj is an expensive novelty.You can buy a lot of gas for the cost of most diesel conversions,on a vehicle that most people will never drive enough to ever recoup the conversion costs.If you have the money and the 'cool factor' is worth it to you though....well go for it and goodluck....i like looking at rigs like that.If I fell into one of the few good donor possibilities real cheap I would still do it.It just seems most people are spending 5-10k on diesel swaps and I cant justify that.
 
This is something ive kicked around for several years but there doesn't really seem to be a readily available candidate thats cost effective enough to bother with.The frame on a 3b isnt really all that strong and your options are mostly really heavy.

Jeep put perkins 4cyl diesels in cj5's from around 1961-1969.They were expensive and didnt sell well but got about 30mpg.Speed wasn't a strong point but the 4cyl gassers of that era weren't exactly quick either.They were good engines but finding one would be hard and you wouldnt get anywhere quickly.

The renault turbo 4 they used in cherokees in '85-'86 is about the right size and economical but very rare and very unreliable.The nissan sd33 and sd33t[turbocharged] engines weigh as much as a bigblock chevy,arent very powerful or reliable or common and are too long for a '71 or older cj.The toyota 2lt 4cyl turbo diesel would be ideal size wise and give adequate power but they only sold a few in the US and canada in the mid/late '80s and are expensive because the toyota guys want them.

The 2.8 jeep put in libertys is good sizewise and powerwise but only came with auto trans in the US and would be $$$$.The late model turbo 1.9 vw golf engine would be good in a cj3b but $$$$.Both are complicated wiring wise.

The 4bt cummins is a great engine but not a cheap swap.Check out 4btswaps.com for plenty of builds.

About the only fairly cheap, and available diesel swap ive come up with is the not very well liked 6.2 chevy.That would be too big to stick in a cj3b imho,but it doesnt weigh anymore than a sd33 scout engine,bolts up to sbc swap mounts and accepts any chevy transmission.I wouldnt want one in a tow rig but ive been quite happy with them in my '85 blazer and previous '83 suburban.You get 20-24 mpg in a blazer/suburban....unfortunately in a lighter cj7/8 or yj you still only get 20 mpg......which is pretty close to what people get with late model fuel injected v6 and v8 gas swaps and less weight and much better performance.

In the end for me the diesel cj is an expensive novelty.You can buy a lot of gas for the cost of most diesel conversions,on a vehicle that most people will never drive enough to ever recoup the conversion costs.If you have the money and the 'cool factor' is worth it to you though....well go for it and goodluck....i like looking at rigs like that.If I fell into one of the few good donor possibilities real cheap I would still do it.It just seems most people are spending 5-10k on diesel swaps and I cant justify that.
I sold the diesel xj with the renault j8s when I bought this Jeep. I wanted an open Jeep, not a big station wagon. The Jeep only had 125k miles, and the engine was ok, but it needed work (overheated on grades and on hot days, thought it might be radiator or the clutch driven fan), and the body was pretty well shot.

They all cost. J.ust E.mpty E.very P.ocket

YouTube - Diesel Jeep Cj drive
 

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