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Discussion Starter #1
Hi, I'm new here. I've been lurking your acronym-rich environment for the better part of a year now.

Yes, I realize the topic is quite generic. It's kind of an open-ended question of "here is my desire, experience, and limitations; help!" :p

Here is what I'm looking to do:

For a myriad of reasons (the awesomeness of diesel engines, fuel economy, vowing to never fly again as long as the TSA is in control of things, family trips, etc.) I've decided to try and build a diesel van.

I've always loved vans, and currently own a beater of an '89 Econoline. She may or may not be salvageable at this point for this project, but it's largely immaterial.

Goals:
* A van with a diesel engine, preferably automatic (I'm young enough and urban enough that I've never learned how to drive a stick properly/well. Ironically and embarrassingly, my wife is better.).
* highway fuel economy as high as possible without significantly impacting the lower gears (5 speed transmission possible?).
* the option of 'upgrading' to 4wd at some point without too much of a pain/rebuild
* Have the above, with a "little" effort in scrounging, a significant effort in work, and as "little as possible" in terms of financial investment (though, I do expect to spend entirely too much, anyway). Cost is, unfortunately, a large factor (the wife is not in full support of such endeavors :p)

Preferences:

I'm open to either a Chevy G20 or Econoline (150, probably) as the host body - the older style ones (3rd Generation of either). My thoughts on this are (please correct any misconceptions):
1) I like the Ford vans better on the inside, but the Chevies seem to handle better and may be a little lighter (eg. better fuel economy).
2) The Chevy vans seem to be potentially easier to "drop" a diesel in due to the 6.2 Detroit being an option in many, and adapting a 4BT to a Chevy transmission easier than to a Ford.
3) Due to the unibody design of the Chevy vans, I'm suspecting they're some odd number (100? 500? more?) of pounds lighter than an equivalent Ford Econoline. This would lead to better fuel economy (but it might be difficult to find a Chevy van in 'very good' body condition to consider the conversion on)

Side note: I'd initially considered an Isuzu. A friend has (mostly) convinced me that staying away from those funny Japanese Isuzu engines would be a good idea - the 4BD ones which are in all those smaller Isuzu/Chevy/Dodge box truck haulers I see around town with the 5 speed transmissions (Isuzu NPR/N-series). If anyone has a reason why this might actually preferable to the above options, I'm all ears.

(I'd been initially considering Isuzu due to lower noise and the possibility of acquiring an entire drive train out of a rolled NPR due to 'nickel and diming'-just-one-more-partism and the like.)

In all of this, I'm a fairly new 'wrench'. I've not done much vehicle work in the past, but I learn quickly and I'm mechanically inclined. KISS is, as such, a requirement for me - I've got limited tools right now, though that plans to change. :p (This is going to be a long-term project. Unfortunately.)

So, on to the questions:

* Can anyone see a benefit to using an Econoline for the conversion, as it regards 'ease to completion'? Or might the Chevy be a better choice (I understand there are more/better transmissions available).
* Is there a specific 4BT model I should look for or one I should avoid for my intended purpose?
* Out of a 4BT and 6.2 Detroit, which of the two am I likely to be able to get better fuel economy in (after 'complete tweaking') with the engine in a standard "conversion van" and a family of 5 in it?
* Which 5 speed transmissions might be available to me? What kind of features?
* Can anyone make (general) recommendations on a good engine/transfer case/transmission/differential/wheel size/etc. for optimal highway fuel economy (while maintaining every-day town drivability)?
* Aside from finding a 6.2 in a wrecked Chevy truck or van, from which kind of vehicles might I locate a suitable 4BT? I've heard everything from 'old backhoes and tractors' on down the line, but I don't really know what I'd be looking for, exactly. ('nickel and dime' price creep applies here, obviously).

Thank you for your patience. And responses! :)
 

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Discussion Starter #2
Sorry, one more (auxillary) question: what kind of intercooler and/or turbo should I be looking at to get (even better) performance?
 

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you may consider Dodge for your donor recipient, as some of them came optional with a the Mopar A-833 Overdrive manual trans. Chevy put that behind some of their 6.2's (ask me how I know), and a 4bd/4bt (would almost go cummins at this point, if you were going with a Mopar base, the lineage is there) would be a nice swap for that.

I am NOT the guru, but.... I am contemplating a 4bd1 (Isuzu) for my one ton 4 dr Bronco... and a certain 'Suzie Guru here suggest 35% over injectors, an HE341, application would be newish Cummins pickup, specifically Common Rail, and the pump maxed. With an Intercooler, the Ford 7.3 aluminum end capped IC, and the Ford 6.0 (much larger from all I have read) are popular swaps for IC needs, he suggested I would be okay on the mpg, and have power flirting with a "modern" diesel. The 6 popper you will be leaching that turbo from, typically has a sticker of 305hp/555tq.. the guesstimation, is the 4bd tweaked to that number, would get me close.

Switching gears, the Ford has plenty of room, and there are some good GM auto's, I say that, because if you were jumping ship TODAY, the better adapter for the 'Suzie is a GM pattern, a common set up for the Cumstain is a Ford pattern... You own the Ford. Cater to that sentimentality, and use whatever funds would be spent purchasing a replacement van, to freshen your susension, paint, whatever areas of the van are lacking in your eyes... Unless its a cancer ridden rust belt victim, then sell/crush/part and shop happy.
 

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i already prefer a chevy over a ford, and i have already seen a some chevy vans retrofitted with different kinds of 4cyl diesels... the unibody setup is not just lighter but also would ease to getting in and out due to the lower floor platform... it's also widely reported that unibodies are more resistant to structure torsion than a body-on-frame setup...
 

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It appears that Ford vans use the same suspension as the trucks in those years. So converting a Ford to 4x4 would probably be easiest and cheapest as the geometry is already hard built into your van. Granted this is pricey but check out this website that does liftkits for your rig.

http://www.jflamecustoms.com/Products.html

You could also look for a used Sportsmobile or Quigley conversion

http://www.sportsmobile.com/4_4x4sports.html
http://www.quigley4x4.com/Gallery/FordProducts/FordProductPhotos.aspx
 

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It appears that Ford vans use the same suspension as the trucks in those years. So converting a Ford to 4x4 would probably be easiest and cheapest as the geometry is already hard built into your van.
(...)
You could also look for a used Sportsmobile or Quigley conversion
actually, those chevy vans don't have a different suspension than the pickups... about quigley, they use mainly the 4wd setup parts out of the pickups to keep it closer to a factory-fitted setup...
 

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actually, those chevy vans don't have a different suspension than the pickups..
My point was that other than the panhard bar mount for the straight axle 1/2 ton 4x4 Fords of the '70s years it would essentially be a bolt in affair! (The Twin Axle IFS abortion that Ford began in '80 would probably totally bolt in, but why even bother) Chevy used IFS with A-arms for 2wd and leaf spring set-ups for 4x4s that would require stripping the frame and welding hangars AND getting the geometry correct.
 

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My point was that other than the panhard bar mount for the straight axle 1/2 ton 4x4 Fords of the '70s years it would essentially be a bolt in affair! (The Twin Axle IFS abortion that Ford began in '80 would probably totally bolt in, but why even bother) Chevy used IFS with A-arms for 2wd and leaf spring set-ups for 4x4s that would require stripping the frame and welding hangars AND getting the geometry correct.
it can be more complicated to do the sas in a chevy but maybe wouldn't be so bad... btw i have seen some 4wd chevy pickups and suburbans from the 70s and 80s with independent front suspensions and coil springs, and was a stock setup...
 

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Discussion Starter #10
I think I've decided to go with a 6.2 Detroit for the first project. Later, when I can find a 4BT, I'll go that route. I think I may have come across one for sale, in a decent host starter G20 body, for a relative song.

Could someone explain what "SAS" is? In this context, it's not an acronym I'm yet familiar with.

I anticipate being able to 'borrow' front suspension and/or drivetrain parts from a Blazer or Chevrolet/GMC C-series trucks at a later point for 4-wheel drive. It's my understanding that the 71-91 generation of Chevy trucks/blazers/vans shared most of the same components in this regard, and as such are (relatively) easy to interchange. (Is this correct?)

Thank you all.
 

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S.traight
A.xle
S.olution.

Which I believe is entirely out of context here, as you do NOT have and I.nferior F.ront S.uspension to replace,

S.olid
F.ront
A.xle

May be a more fitting acronym.

The 6.2 rig is a good chice, not the worlds fastest diesel, but they make more diesel than they burn (read that as extremely thrifty)

Scuttlebutt has it, they do not like a turbo, and if one is going to add a hairdryer (turbo) one needs to source a 6.5 crank, and swap that in place of the 6.2 crank.
 

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Discussion Starter #12
Interesting. Any idea why they don't like a turbo? What about the various other performance 'accessories' (eg. intercooler) which go 'with' a turbo? (Sorry, I'm not yet intimate/familiar with what all is involved in that department.)
 

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S.traight
A.xle
S.olution.

Which I believe is entirely out of context here, as you do NOT have and I.nferior F.ront S.uspension to replace,

S.olid
F.ront
A.xle

May be a more fitting acronym.
i always used sas for S.olid A.xle S.wap for vehicles with stock independent front suspension...
 

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(S)traight or (S)olid
(A)xle
(S)ystem or (S)uspension or (S)wap

And if starting with a '70s-'80s 2wd van he will have an IFS (I)ndependent (F)ront (S)uspension and a SAS would be the easiest solution for a robust design.

As far as putting the GM truck 4x4 front suspension under a G series van You'd have to check out the frame set-up on each and determine how close they are and if worth the effort. The Ford design may still be easier to adapt even into the GM chassis.
 

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I think I've decided to go with a 6.2 Detroit for the first project
We TRY to not perpetuate the mythical link between the GM 6.2 & 6.5 diesels and the Detroit Diesel Company's series of engines. The roots of this go back to the earlier days when some GM medium duty chassis were available with engine options from Detroit Diesel. Similar origins for the same reasons of the myth that Ford owns Cummins.
 

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Yeah, I uh, figured since he was replacing a 2wd susp with 4wd bits... he would be actually using a SFA to create an SAS.. but I have always heard the reference to 4x4 units, and I was moderately stoned on vodka/norco.. I have an abating abcess.
 
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