I have a 1989 Mercury Grand Marquis with a 302 engine and an AOD transmission with a 4.11 8.8" rear end. i am interested in swapping my engine with a diesel eventually, as the car is still in excellent shape and very reliable. This would be a long term project as the car only has 202,000 miles and still runs very well, and gets 20 - 24 miles to the gallon. What would be involved in the switch? I am aware that I would need a high pressure fuel pump and some lower gears in the rear end, but is there a diesel made with a 5.0 ford engine that will be a direct switch? What about the emissions? what has to happen with the catallytic converters and all or that stuff? I am not looking for speed or quickness as much as the gas mileage. Please let me know.

-- Michael Graveman (graveman@ku.edu), June 07, 2001

Answers

i wouldn't do it. if you want a diesel car or pickup, buy one.

the costs ( let alone the headaches and frustrations, skinned knuckles, and probable failure of switching a gas engine to a diesel), i repeat, the cost considerations would buy you a hell of a lot of gasoline. you'd be spending dollars to save pennies. not worth it.

i used to do this back in the early 80's. just wasn't worth it, and my customers were never satisfied. it was a nightmare.

in my humble opinion, the ONLY reason to do this would be as a "project" to ONLY see if i could do it, as a challenge.

as a slightly different subject, i've been contemplating buying an older diesel volkswagen rabbit or pickup or van, just for the kicks of seeing if i could successfully make biodiesel and drive around on it. for whatever its worth, those volkswagen diesels are as tough as nails, very reliable and simple.

my best wishes to you

gene

-- gene ward (gward34847@aol.com), June 07, 2001.

All I can assist you is to state take the liter size and multiply by .61 to get cubic inches. Engines and technoligy ran off and left me 25 years ago.....

-- mitch hearn (moopups1@aol.com), June 07, 2001.

Have you considered the autogas conversion? I don't know what it would be called there, or what the economies would be, but running it literaly on gas rather than liquid. Most taxis do that here - high mileage makes it worthwhile.

-- Don Armstrong (darmst@yahoo.com.au), June 07, 2001.

transmissions wont switch,, totally differenet bell houseing, and the motor mounts are in different places also

-- stan (sopal@net-port.com), June 07, 2001.

I dont know if it would be economically worth it unless you can find an efficient 6cyl diesel such as old Mercedes diesel and even then it only got around 30mpg with a 4speed manual tranny. Not alot of difference over your present 20-24mpg. Need transmission that mates with donor engine also unless you want to custom make adapter plate. Then again your automatic probably has a computer controlled overdrive which wouldnt work with non computer diesel. Auto tranny would need rebuild now also unless you have recently already had this done.

One other point, a diesel engine is very heavy compared to gas engine, so you would need to beef up front springs. Remember diesels tend to have very slow acceleration unless turbocharged/supercharged or greatly oversized for the vehicle like some of earlier Ford diesel pickups. I dont know, arent most diesel pickups turbocharged now? They are out of my price range so not familiar with them.

-- HemitJohn (hermit@hilltop_homestead.zzn.com), June 08, 2001.

I performed a similar swap in a 1981 Buick Wagon. In 1990 I Replaced an Olds 350 diesel with a GMC 6.2 liter diesel. It required basically gutting the car...nothing original fit the new engine so I ended up with new radiator, new transmission, shortened drive shaft, different AC compressor, different alternator and power steering pump, modified steering column. Had to play with front springs to get the alignment right because of different engine weight. Had to replace rear control arms to line up the new short drive shaft angles. Speedo gear was all wrong and had to be replaced. All the hoses (PS, Air, cooling) are now custom. Oil cooling lines are braided steel because nothing else would fit well. Had to cut and re-weld the pan to fit the automotive cross-member. The result is a vehicle that I am still driving and gets 24 mpg. It's a much better setup than the original but I would never do it again. Definitely not cost effective (I spent about $5000 doing this). If you like the car put in another 302 and keep going. It will be faster and cheaper...unless you like the sound, smell and feel of the diesel (it's sort of like lead poisoning) and if you are ready for a challenge..then have fun! Be sure you know some good parts guys at your local dealer because you'll need to do lots of research to find out what fits and what does not.

-- Conrad Otto (conked@swbell.net), March 06, 2002.