HYBRID - Using leaf springs to locate coil overs?

I'm putting a diesel engine in my CJ. The engine weighs 600# stripped (800# dressed and ready?). I want to keep leaves spring under but math says spring rate would be kinda high and stiff to carry 4bt armor & a winch. Possible solution : using mainleaves (each corner) to locate axle and then use coilovers to reach the height and rate(s) I seek. Still use shackles and all. Am I crazy or could that actually work? If it does work could I use my original non lifted springs and just let them hang the axle(s)? Just using them to locate instead of designing, building, buying, damaging, repairing a link type set up. Could use original mainleaves and have them "wrapped" (military) and even add a torque spring or some other anti-wrap deally or how about just fabbing up one link to combat/ minimize axle wrap? Any geniuses or fellow crazy bastards have any ideas? Am I "on to something" if it works and someone starts making this type stuff I want mine for free! Just getting ready for build over next couple of months and want "the best" for "the least" amount of work and benjamins. OR - should I just "man up" and buy the rubicon express extreme set for a YJ? Remember I'll essentially have a 'big block' over front axle and a winch, it's that whole Archimedes thing.  

Most of the conversions I've seen involving diesels simply seemed like a good way to ruin a perfectly good Jeep and a tow rig all at once.

I have seen some swaps with smaller, hard-to-locate diesels. However, none of them was very driveable. Most of these low-horsepower diesels came from Frito-Lay trucks, wood chippers, or farm equipment. None of 'em scream performance...

Instead, you were rewarded with an overweight pig under the hood that weighed more than a big-block V-8 and had half the horsepower. Torque will only get you so far, and that's straight to the bottom in sand or a mud hole.

-John Cappa, Oct 2006 Trail Head

If just putting a diesel in a CJ is it, don't sweat the details. But if you want it to be worth something when you're done... What are your objectives for the rig you're trying create?  

Obviously none of yall have ever had a diesel, and if you did it must have been an old chevy. The 4bt cummins only weighs about 250 pounds more than the AMC 304, and the 4bt is the same motor as the 6bt 12 valve found in dodge ram 2500 and 3500s in the 90s, which is a bad ass motor, so you can take the 4bt and turn the fuel up on the pump, add an aftermarket fuel plate, and a good straight pipe exhaust, remember that diesel need no back pressure, and youll have a better performing motor than a big block and get in the 20s AT LEAST for fuel mileage. DUSTDOGGY, go to the forums over at diesel power, there are some folks over there that have done diesel swaps and know just as much about off-road worthy parts, and arent diesel-illiterate like they are here. Im doing the same swap this winter, and although i cant help cause i havent worked out my details yet either, dont let these bozos talk you out of a cool swap. There was a CJ5 in the Four Wheeler Top Truck Challenge in 07 that was not only badass but it was very competitive, with a stock 4bt. Not only that but unlike a POS gas motor, all it take to make a mechanical diesel engine like a 4bt run under water is a snorkel, there is no distributor to get wet, no spark of any kind. Remember, REAL engines dont need spark plugs!  

Which part of laying out your objetives so that you can be successful in your efforts makes one a "bozo"?

Maybe his objectives can be met in any number of ways that make more sense, and cost less money than being blinded by ones diesel bigotry.  

I think you will be better off simply building a proper four-link or put some heavy-duty leaf springs in there. A traction bar and main leaf will not control the torque. You will spit driveshafts...by the way, 250 pounds more than an AMC 304 is heavy! Just so ya know.  

backwoodsboy916:
Obviously none of yall have ever had a diesel, and if you did it must have been an old chevy. The 4bt cummins only weighs about 250 pounds more than the AMC 304, and the 4bt is the same motor as the 6bt 12 valve found in dodge ram 2500 and 3500s in the 90s, which is a bad ass motor, so you can take the 4bt and turn the fuel up on the pump, add an aftermarket fuel plate, and a good straight pipe exhaust, remember that diesel need no back pressure, and youll have a better performing motor than a big block and get in the 20s AT LEAST for fuel mileage. DUSTDOGGY, go to the forums over at diesel power, there are some folks over there that have done diesel swaps and know just as much about off-road worthy parts, and arent diesel-illiterate like they are here. Im doing the same swap this winter, and although i cant help cause i havent worked out my details yet either, dont let these bozos talk you out of a cool swap. There was a CJ5 in the Four Wheeler Top Truck Challenge in 07 that was not only badass but it was very competitive, with a stock 4bt. Not only that but unlike a POS gas motor, all it take to make a mechanical diesel engine like a 4bt run under water is a snorkel, there is no distributor to get wet, no spark of any kind. Remember, REAL engines dont need spark plugs!

 
When you're finished....you're done

How long have you been saving that? And you're going to waste it on this? LMAO!  

Couldn't help it. It was that or shoot the computer. What can I say....Im a "BOZO"!!!  
When you're finished....you're done

hey, no one's opinion makes them a 'Bozo" and no one will talk me out of the 4bt plan (unless I could find a better diesel). I have an old dodge dually flat bed that starts almost everyday, lights up all 4 duals (and could melt them if I tried hard), gets 24-28MPG with my slipomatic 727 depending on load and driving plus hauls 3 tons around on a regular basis. It's waterproof, efficient, reliable and well, I've got close to 400K on it now and like it. no wiring just one to shut off & one to start. Should be realatively easy (and affordable) to put 200HP & 400/450TQ. to the ground and maybe get 30+mpg. Run fully oiled at 45/50 degrees on all angles, two major drawbacks are that it is heavy (600 dry) and the max RPM is only 3200 (without getting crazy) but peak fuel efficiency is around 1800 (depending on boost/fuel/temp. I like the idea because it's different, sounds bad ass (too me anyhow) I could get samuri mileage with 502 Torque all just over idle. I'm sure I'll miss my 4.2 but I'll also miss the 472/500 Caddy mill too. It's what I like and what I want. Just wanted opinions on spring Idea. I'm ready to (if need be) get the Rubi-xpress 2.5" ext. dty. or .... have two/three more months to decide.  

Proffitts Cruisers, who install 4bt's and V8's into Land Cruisers recommends serious consideration of late model fuel injected GM V8's over 4bt's for their conversion customers.

Their experience shows that a turned-up 4bt can deliver performance at similar levels as a GM V8, but the mileage of the 4bt suffers, bringing it very close to the mileage of the GM V8 conversions.

Coupled with the fact that it is somewhat noisier, especially turned-up, and a somewhat expensive engine to purchase, they feel as a daily driver, serious consideration should be payed to a GM V8 engine swap instead.

Converting to a 4bt for fuel economy reason, they say is mis-placed. The biggest reason that they would recommend a 4bt over a GM V8 is for the "unique aspects" (meaning cool) of the conversion and to run biodiesel fuel.

I guess they drink Kool-Aid from both pitchers.  

I looked into it, even personally saw a couple in person that were put in CJs (both kinda hack jobs) I know enough about diesels to be dangerous so I don't ever think I know what I don't. One thing the hacky guys said was they were both in the mid 20's MPG wise.
I seem to remember that only one of them had an overdrive but it was an auxillary unit rigged up with a crazy driveshaft angle. That kinda crap ain't me. I'm not going for show truck but if I'm going to spend the time AND money to do it, I want and even expect to hear "nice job" when someone gives it the once over. It doesn't have to be shiny to be nice, it just has to be nice. OK OK the crazy spring thing was just a thought, and I know that it probably can be made to work to realize some benefits Or just waste a bunch of time and ruin a bunch of stuff. But the diesel thing ... that will work, it's just different than gas, better in some areas and not as good in others. I think diesels are cool. Cool sounding, cool looking, cool running ... just heavy and slow, but so is a locomotive.  

I'm certainly not trying to change your opinion about diesels. I'm just trying to understand your objectives for your build-up.

That way some meaningful and thoughtful information can be shared to help meet those objectives. What are you going to use the CJ for?

I think diesels are cool too. I even own one. It just so happens to be in a 40ft diesel pusher motorhome. I just don't think old diesel technology, especially from the early '90's and older, belongs in everything. Diesels have a niche.

Locomotives are electric because of the downfalls of a diesel engine's powerband. The gearing demands are too great to keep the diesel operating efficiently. Not to mention the mamoth size of the transmission that would be required. Electric motors deliver all their torque right from zero rpm.

So even in a locomotive, a diesel is not praticle for propulsion, but makes a great engine for driving a generator for the electric motors.  

objectives: unique, what I consider a cool vehicle. Hell there are people out there that think CJs suck, TJs suck, YJs aren't real blah, blah, blah. The 4bt Old tech, mechanical injection, properly maintained should last "forever". torque off idle is what a big block gets after it winds up a bit. Hey I know, gas has advantages. I had a caddy motor and even though gas was cheap it sucked burning so much of it so quickly. I've looked and read and seen alot of different posts from different people alot of different places and they all seem to say about the same thing 25-35mpg. WOW on the power (I'm a diesel guy so I know the dif between HP & TQ.). Except for the bitching about all the little things that went wrong with the swaps (like alot of swaps) and costing twice what they thought it would. I haven't really heard that much bad as long as they are operated in there intended environment. Not much off idle dune blasting or mud whompin w/54's. I could care less about that stuff. Dunes? Never saw the point, beach, fire, bottle of wine - sure!!! Big field that's mud side to side? Hey lets drive around out there until we get stuck or just try to get across and spend the rest of the day getting back or cleaning. Guess you could use the TQ. to upshift in a mud hole. Do I know exactly what will be in regards to this? Hell no. am i gonna drop a 4bt in? hell yeah. will I like it? probably. will I wish I had a tight small block singing @6 grand maybe sometimes. will I have a *** eating grin as I idle up some sandstone ledge knowing full well ..."at least I won't stall". Will I brag everytime I put fuel in (hopefully) about how I get 35mpg in a jeep runnin 38's? I want something different, powerfull, dependable, loud, smelly and obnoxious to boot. I have always thought that I would use regular leaves just to be traditional and because they have served everyone fine for a hundred years (inspite of their limitations) just like the diesel. This isn't a high reving mill, but it's not a lugging, wheezing non turbo diesel. Yes the power band is kinda narrow Off idle to1800rpm you get torque, torque flattens out and drops a bit as the "anemic" HP catches up and drops off more and more as rpms rise until the fuel gets shut down at whichever rpm you choose to (I like 3200 sensible, some wheel speed but the next step would shorten the life triple the cost and double the danger) Hey I had a 428CJ mustang grabber blue & a nice coronet with a 440 commando I know the differance. I think the diesel works better off road. period. Pre running? not naturally. military likes the diesels and for more reasons than they only need one fuel type. They work well even exceptional within their limitations. I am going to get this thing built over the next year and I will be @ Easter Jeep 2010 and I will be driving out there like I have 5 times before except this time I will Hopefully get 40MPG, have a blast and not have to call it quits because I already burned 20+ gallons of gas through my 4.2 before dinner or before lunch with the 472! sorry for the wind.... the wind is strong ... the wind is long.  

Im new to being a jeep guy, but not to off road trucks, but all of mine have been fullsize diesels, so i never thought that 250 pounds was a big deal. Does that mean that if a 250 pund guy was to ride on your bumper (hypothetically of course, that would be dumb) that your jeep couldnt handle it? I mean i understand that the front end will be lower and im gonna account for that, but that seems like an easy enough fix. I was had already decide that i was gonna do the 4bt swap and i thought the 304 was a lot lighter, when i looked up the weights of the two engines i thought it was great. If im missing something fill me in but i keep trying to picture a 250 pound guy on the front of my jeep and how much that would actually affect it...  

Nice diesel discussion you guys seem to have covered most everything i think i learned something if it's all true and not just opinion(I'm not calling anyone a liar just don't belive everything i read especially april issues of jp).Didn't dodge use a coil spring/link in the 3500s,if it works for a one ton plus rig with a 6cyl it should be fine in a jeep with 2 less cyls. and my 185lbs jumping on the front bumper of my cj barely makes it move so whats 250?Of course the ride and flex suck in the cj so don't use those leaves(2.5 budget lift).