alecksia

I don't know much about diesel engines. I was wondering whether it would be possible (without a ton of money) to convert my 6 cyl into a diesel, in order to go biodiesel, and what it would take to do it. I want to avoid an engine swap.

davida

Your going to have to swap engines to do this, I don't know if you remember this but in the 80's GM tried to convert a gas engine into a Diesel and then they even sold it to the public, it was a complete and utter disaster, it's one the main reasons we don't have more diesel cars in America, they are common place just about every where else in the world. The Cherokee was sold as a diesel in other country's. It seems like canidate for a small 110hp diesel.

Hommersimpson

cant make a gas engine a diesel... well you can.. but the custom parts cost you 15-20k... lol diesel engines compression ratio is like 24:1 about the only thing that could be used would be the block and crank.. couldnt use the rods pistons and cyl head.. need injection pump... yea 20k... lol

98 JeepJeep

trade it on a 4cyl XJ or deal with it...these arnt gas sipping Hybrids.

alecksia

Damnit.

boneguru

there are threads about swapping a diesel into the xj's, just not cheap or easy....
I would love to do it myself when it becomes closer to affordable, I dont mind paying someone to handle the easy part..

5-90

The engine mentioned in the second post was the Oldsmobile gas-fuelled 350 - and was an unmitigated disaster (and why it's taken Diesels so long to catch on in pax cars here in the States. The Olds Diesel 350, put in the Chevvy, Olds, and Caddy vehicles, left an awfully bad taste in everyone's mouth for the last 25 years...)

Generally speaking, it's not possible to readily convert a gasoline engine to run on any variety of Diesel fuel - the first problem is that you will have to bring the compression ratio up from 8.7:1 (your 1990 6-242) to about 15-16:1 (typically, the minimum useful compression for a Diesel-cycle engine. Diesels ignite by compression.)

Assuming you can bring the compression bit off, you then have to arrange fuel delivery (several hundred to a couple thousand PSI - usually done as a two-stage system,) and fuel injection (a couple thousand PSI, directly into the cylinder, after the valves have closed. So, a cylinder head redesign as well - the spark plugs usually aren't in a good place for Diesel fuel injection spray introduction...)

Redesign the piston to promote atomisation maintenance of the fuel after it's been injected (instead of it spraying all over the piston head, and most of it not lighting,) and still maintain the 15:1 or better compression needed for efficient combustion. (Yes, 15:1 can be considered "low." Some large Diesel engines - like the big Cummins used in heavy trucks - run 25-28:1 without any trouble.)

Redesign the block casting to contain that sort of compression pressure and the resultant combustion spike.

Redesign the crankshaft so you don't drive the crankpin out of it in short order.

Let's see - we've redesigned the fuel delivery setup, the cylinder head, the engine block, the crankshaft...

OH - redesign the intake. Diesels don't have throttle valves, the engine speed is controlled by fuel metering. Therefore, you have to make sure you get as much air through the intake as possible (which also means a farkin' huge air cleaner element! Diesel air cleaners can be somewhat larger than a #10 soup can, or a couple of five-pound coffee cans in a stack...)

Redesign the exhaust. Exhaust Gas Temperatures are considerably higher in a Diesel.

It's a cinch that the transmission will grenade fairly quickly due to the input torque. If it survives, the driveshaft is next in line to let go (tubes and yokes or Cardan joints.) If that holds on, you're looking at the axle - and I'd not consider the D30 or D35 to be any sort of "strong" to go behind a middlin' useful Diesel engine (they survived behind the Renault 126ci and VAM 15-odd ci, but they're small. Very small.)

Consider working in a turbocharger - they not only make Diesels more powerful, but also make more efficient Diesel combustion happen.

Where's that list again? Block, head, crank, intake, exhaust, fuel delivery, air cleaner, ...

Easier to find a small Diesel engine and drop it in. Since the XJ is a unibody, I'd suggest a small four- or five-cylinder Diesel of not more than 200-220 cubic inch displacement. Any more than that, and you're probably looking at enough torque to twist your front subframe if you don't reinforce it considerably (don't let the HP ratings of a Diesel engine fool you. A Caterpillar 3208 V8 Diesel engine is rated for something near 100 brake horsepower, but up around 600 pound-feet of output torque at the flywheel. It's torque that will twist up drivetrain parts and bodies... Most Diesel engines will have a similar disparity in horsepower/torque output ratings.) You'll still have to finagle the exhaust, turbocharging, fuel delivery, and air delivery - but at least the really hard engineering has been done for you!

Good luck! You will need it...

(Oh - if you want, there's a Yahoo! group dedicated to swapping the Cummins 4BT four-cylinder turbodiesel into various vehicles - http://autos.groups.yahoo.com/group/...guid=157814082. However, you should be advised that the Cummins-built Diesel engines, while inline and quite efficient mills - are rather tall. This could lead to a great deal of difficulty when swapping into a unibody vehicle, or a vehicle with limited space in the engine compartment - particularly vertical space.)

wheeler

if i had realized i couldve gotten a diesel XJ i wouldve had one flown in..... i dont care the price f' it that would be bad@ss and probably cheaper then doing a swap of everything...

DRUNKEN DIXIE

Yep about half the XJ's over here in the UK are Diesels.

dyte2004

run it on propane

fantic238

good one, or bioethanol conversion kit available from Brasil...

fantic238

80% here in Italy are diesel.

fantic238

Modern common rail diesels have a throttle valve used to dampen vibrations at idle and when shutting off.
152ci... they're not that small

1995-2001 xj VM motori 2.5 four cylinder turbo, 114hp 221lbft
1993- 1998 zj VM motori 2.5 four cylinder turbo, 114hp 221lbft
1998-2001 wj VM motori 3.1 five cylinder turbo, 140hp 290lbft
2002-2008 kj VM motori 2.5 four cylinder turbo, 114hp 221lbft
2008-today kk VM motori 2.8 four cylinder turbo, common rail, 177hp 295lbft
2007-today jk VM motori 2.8 four cylinder turbo, common rail 177hp 295lbft
without mentioning Chrysler Voyager, Dodge Dakota and Dodge Nitro that have the same engines.

The 2.8 common rail (1800 bar injection pressure) is produced in Toledo, Ohio.

Some news you might not know:
In 2003 MTU and VM have signed an agreement in which the off-highway engines built by VM Motori Sp.A. in Italy will be made available to the DaimlerChrysler Off-Highway sales organization. The agreement covers MTU Friedrichshafen GmbH, the off-highway segment of Detroit Diesel Corp. (DDC) and the off-highway segment of the Commercial Vehicles Division of DaimlerChrysler AG. In addition to the worldwide distribution of VM engines, DaimlerChrysler Off-Highway will offer worldwide service and global availability of spare parts.
The agreement brings the VM series D700, HR and SUN two-, three-, four- and six-cylinder engines with an output of 30 to 300 hp into the fold, as well as VM Motori generators and pump sets which will also be integrated into DaimlerChrysler Off-Highway.
Cummins Inc. announced that it has extended its exclusive supply agreement with DaimlerChrysler Corp.'s Chrysler Group for diesel engines used in the Dodge Ram heavy-duty pickup truck. Although specific terms of the agreement were not disclosed, the engine system agreement includes consideration of Cummins as a supplier for the diesel engine aftertreatment system. The agreement additionally paves the way for collaboration on diesel engine technology beyond the length of the contract.



This means you already have VM engines available with Cummins, Detroit Diesel and Chrysler written on them since 2003 and they all fit in the cherokee with little effort, otherwise you go to Canada and you pick one in the first JY you find on your way.



http://www.thehulltruth.com/boating-...-p-diesel.html

Next step will be John Deere and Perkins.

davida

Here's a pic of the Olds 350 Diesel, Ugly but interesting!!!

syncview

Get a Toyota 1KZ engine, works perfectly with the AW4 transmission as well

Normal practice here in Pakistan.