1971 cj5 6.2 turbo diesel swap waste oil

so ive got my cj5 that i love, but with its current mild build 350 gasser, and although its a rocket on wheels,it gets 6mpg no matter how i drive it...yeah ouch and with only a 10 gallon tank it dont go far, and with gas at over 4.23 a gallon for reg unleaded the jeep is seeing less and less action.


so for the last few years i have been buying diesel rigs converting them to run off waste veggie oil and running around for cheap.

I started to think about my dilemma. And though from what i know the 6.2 will bolt in the 350's place...i think?


So my idea is to take a 6.2 or 599 block 6.5, run it all mechanical with a turbo setup timing gear conversion, and create a waste oil tank to run it around for free.


My rig is already ideal for this conversion because i have a late model cj front with disc brakes, a turbo 350 tranny and dana 18 with a warn overdrive, and 4.27 gears and 33's(spring over lift)

So my question to you all is do the 6.2's bolt into place from what i have read/heard? Are the motor mounts etc the same? will the flex plate from the 350 have to be switched over to the diesel to work?

 

Wouldn't a 6.2 be a LOT heavier than a 350?
And 6 MPG is bad-I think what you have should get much better than that.

 

the 6.2 is not much heavier, weighs around 675lbs (100 pnds more or so) i can get new springs if need be.....yes 6 mpg is terrible, and no its not running crappy. It runs very very well. My friends truck doesn't get past 7mpg with the same engine.


that is the point of this whole idea, even if i double my mileage at 12 mpg, which ive never driven a 6.2 that has gotten under 15mpg and run nearly free fuel that is still a huge improvement.

 

a 6.2 is heeevvvvyyyyyy, what about a 80's diesel olds motor

 

I wouldn't wish that on my worst enemy! How about a Mercedes diesel? Adapters and oil pans are available.

 

yes no older than a 6.2 as they are very very troublesome "boat anchors" ha

but seriously though the olds diesels were gas motors converted to diesel=trouble

the 6.2's on the other hand were designed from scratch to be a diesel, and keeping in mind that its design is older than me by several years it has always served me well

 

You are going to need more than new springs. Frame beefing will be necessary and possibly (probably) beefing the front axle as well. You don't say what 350 you have now. Pontiac, olds, Buick, and chevrolets have all been installed in cj's. How can one know what will fit your mounts without knowing more info.
It sounds like an interesting swap but you also need to consider the torque of the motor and whether your running gear will hold up. It's much more than just the weight and Bolt-in to be considered. Many consider the 6.2 to be a troublesome boat anchor as well, although I agree not anywhere as near problematic as the olds 5.7. If you proceed I'd suggest the 6.5 turbo diesel minimum for the amount of work involved. Physical size must be considered as well. A short fender is typically tight with a small block v-8. Add the physical size of the motor you are thinking and there will be some pretty major surgery involved. Not saying it can't be done but all things to consider
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Yes. I should have said the current motor is a 1969 4 bolt chevy 350....it will be an all mechanical 6.5 turbo setup on it. I know it can be done as there is the same setup in a lot of ausie rigs. It may be tight but I'm sure I can make it work. I've considered the strenght of the axles etc etc and they have so far stood up without any issues and twice the hp this turbo motor will be making. Its got a 4 core griffin aluminum radiator in it now. And a 10 inch electric fan.
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HP does not break anything. Torque does.

 

True. But in a rig that is half the weight of a of my last turbo k5 which had 10 bolts
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rather than go diesel, i would swap in a 4.3L v6. I think the 6.5 would eat your tranny, transfer, drive shafts and front axle at regular intervals, costing you more $$$$$ than you would ever save on "free" fuel.

 

I have considered this.....but the 350 that's in there now generates around 380 ft lbs according to all the builders specs....one thing I just realized though was I need dimensions of the widths of the two engines, I may not have enough room for the turbo manifolds, which would then put me at around 175hp max with the na engine in top shape possible, most likely less
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What gears/induction are you running to only get 6 mpg out of a 350? I get about 18 out of my nominal 383 on the road and only get into single digits when off road and low range. It is not exactly mildly built either. Something is not adding up.

 

Its got 4.27 gears, edelbrock performer 600 with off road needles and valves stepped down one jet size with the use of aktronic fuel air vacuum machine....according to the machine. That's is the sweet spot for fueling and the way it runs I would agree....just gets terrible mileage
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I was thinking the same thing.

 

I was thinking the same thing.
My 327 is fairly nasty, for a pump gas motor anyway, and I’ll still get around 15 MPG with 4.27 gears and 33” tires.

 

people have told me this over and over, and from what i have found and the engine builder there is nothing wrong with it....but yet it gets horrible mileage

 

My 24' Class A motorhome with a mildly built 454 gets 6-8 mpg loaded to the gills. I'd say something isn't right.

 

I guess if the 350 was mine and only getting 6 mpg, I would be having a serious look at the cam, along with carb and manifold; and in your case the torque converter/transmission. I don't care much for autos so have only limited off road experience-one J20 with the TH400-and I would take just about any manual trans over that one. I am also running the 33-12.5 BFG's so that is not likely a big factor. I do have an OD which would explain some of it, but not by a factor of 3x.

Geezz, I have a 1T Chevy with a warmed over 454 that gets a very consistent 13 mpg. Double your mileage and drop a big block in there. Should be all the torque you would ever want and it will bolt right up-however, might spit that TH350 out the bottom.

 

yeah something is not right, but every mechanic ive paid to look at it says the same thing "its and old gas pot in a rolling block, its not going to get mileage, more like feetage" ha!

im at a loss with this engine and so im ready to move on. A supercharged v6 vortec would be nice.