Hello, Allpar Forums member or visitor! If you were a member, you would not see this ad!

Register or log in at the top right of the page...

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

A-100 Van: Replacing a 273V-8 with a 3.9lite V-6

Discussion in 'Pre-1994 trucks, commercial vehicles' started by Rampart66, Jul 14, 2017.

  1. Rampart66

    Rampart66 New Member

    Joined:
    Jul 13, 2017
    Messages:
    16
    Likes:
    2
    Hi Guys,

    I've had a '65 Dodge A-100 van for many years. It originally had a 273 V-8 with auto tranny. I got the original tranny with the van, but the engine was long gone. I'm getting into my retirement years now, and had a wild idea about putting a 3.9L V-6 out of a junker 1992 van I have, into my engineless A-100. Nobody on the Dodge A-100 Yahoo group, of which I have been a member for 15+ years, has ever put a V-6 into an A-100. From what I've read on various posts here, it sounds to me like 273/318 blocks are the same width as the 3.9 V-6. Any idea what I would use for motor mount brackets and motor mounts? Is there a set-up I can buy, or will I need to fabricate something? Also, I was wondering if my original 1965 727 tranny will bolt up directly to my 1992 3.9 V-6? Am I getting myself into a real can of worms by thinking this will work? I like oddball stuff, and this is about as oddball of a conversion as it gets. I once had a '67 Satellite 318 that I put a '60 Imperial 413 into. Thanks in advance for any help you can supply me with.

    Rampart 66
    St. Augustine, FL.
    '71 Dart Swinger, 7 Dodge vans ('65 to '03), and 8 vintage Serro Scotty travel trailers
     
  2. valiant67

    valiant67 Rich Corinthian Leather
    Level III Supporter

    Joined:
    Jan 7, 2003
    Messages:
    31,636
    Likes:
    10,867
    The 3.9 is a 318 with two cylinders chopped out. The mounting areas on the block might be the same. The bellhousing on the transmission will bolt to the 3.9. But the 1992 engine expects a crank sensor notch in the transmission unless you run an aftermarket ignition. You may also need to pay attention to the torque converter as it may not work with the newer crank. I don't remember the details.
     
    Rampart66 likes this.
  3. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    29,868
    Likes:
    3,241
    And 1992 has multi-port fuel injection, so you either have to scavenge a manifold, carb and associated hardware, or retrofit the van with the entire engine and control harness, and computer.
    Much easier to take a 1960s vintage engine and install it.
     
    Rampart66 likes this.
  4. Rampart66

    Rampart66 New Member

    Joined:
    Jul 13, 2017
    Messages:
    16
    Likes:
    2
    Since I have this complete and good running 1992 van (smashed when a tree fell on it), I have all the wiring and computer. This obviously isn't going to be a drop in, have it running in a day kind of thing, but I'm hoping to make the fuel injected 3.9 and antique 727 transmission that I have work. It also may be possible to use the transmission out of the 1992 van, but I'm not sure length wise. My "shorty" '65 van's original transmission has a short tailshaft on it, which allows room for a very short driveshaft. Any longer of a transmission won't work with a V-8, like the 273 V-8 the van was originally equipped with, but the shorter length of the 3.9 may create room for a longer transmission. Lots of "what if's" for sure, and I greatly appreciate everyone's input.

    Thanks!
    Rampart 66
    St. Augustine, FL.
     
    Bob Lincoln likes this.
  5. dana44

    Ad-Free Member

    Joined:
    Jun 17, 2002
    Messages:
    19,324
    Likes:
    1,236
    OK, here are some of the things to work with and they aren't all that bad.
    Unless you go with a carb and intake, there isn't the crank sensor available for the EFI, use the van trans and get the driveline shortened, it will work, drivelines can be shortened easily, lengthening them, not so much (haha). It will be able to do the arc to the rear end, that has been done before. The mounts should not be an issue and should locate the engine in the proper location to start with. The 92 trans mount, I believe, will need to be modified to lower the tail of the transmission (from what I recall about the trans being swapped into other A, B and E bodies, but not positive about the floor of the van, maybe an inch or to raise, but being an old van, plenty of ground clearance to have it lower in the tail so you don't have to do that, just make sure to verify your transmission, rear end angles so they don't bind, but this is minor adjusting. You will also need the fuel tank and fuel pump/lines, etc. The tank is plastic, so that helps, but the fuel pump inside, if it can be used and simply replace the original, that would be wonderful to ease that issue, otherwise the fuel pump has to go into the old tank, or, an external, I believe, 55psi fuel pump is needed. Wiring, is not that much, it's a small harness compared to some, but a little fun because of the fuse block under the hood (with all the relays), and for fun, wire in the 92 steering column to have all the signal stock hookups, wipers, signals, lights, which would be pretty cool and updated. Sounds fun.
    So summarized, engine bolt-in location, not a problem, trans should be the new one, not the old one, rear mount and driveline work, but not serious.
    Wiring of the engine and fuse block for relays pretty much needed, and if you want, headlight wiring is actually separate, if not mistaken, so your call on that.
     
    Bearhawke and Rampart66 like this.
  6. GLHS60

    GLHS60 Well-Known Member

    Joined:
    Jun 23, 2008
    Messages:
    1,390
    Likes:
    372
    I believe 1965 was the last year for the internal shift cable, later vans used an external shift cable.

    The rear mount is unique to the A 100 as well, a couple of things to check out.

    This will be very complicated compared to a 413 in a Satellite!!!

    A 318 may be the way to go but best of luck and keep us updated, we like oddball.

    Thanks
    Randy
     
    pt006 and Rampart66 like this.
  7. Rampart66

    Rampart66 New Member

    Joined:
    Jul 13, 2017
    Messages:
    16
    Likes:
    2
    Thanks, everybody. You ROCK!!!

    Rampart 66
    St. Augustine, FL.
     
  8. pt006

    pt006 Active Member

    Joined:
    Dec 24, 2014
    Messages:
    1,281
    Likes:
    490
    A 318 LA carbed engine from 1967 and up or an early 360 would be the easiest. ------- 413 in a Satellite, aah the good old days.
     
    Rampart66 likes this.
  9. scatpack_69

    scatpack_69 Active Member

    Joined:
    Feb 5, 2013
    Messages:
    168
    Likes:
    166
    Rampart66 likes this.
  10. Rampart66

    Rampart66 New Member

    Joined:
    Jul 13, 2017
    Messages:
    16
    Likes:
    2
    Oh, I agree, and I have a couple of late 60's/early 70's 318's that I could drop into my van. BUT.....I always like the unusual, and doing things the hard way. Nobody that I know of has put a 3.9 in an A-100, so I think I'm going to give it a try. If it doesn't work, I can always go back to the 318, but that's SO boring!
     
  11. Rampart66

    Rampart66 New Member

    Joined:
    Jul 13, 2017
    Messages:
    16
    Likes:
    2
    Can I simply use the harness and computer out of the donor van?
     
  12. scatpack_69

    scatpack_69 Active Member

    Joined:
    Feb 5, 2013
    Messages:
    168
    Likes:
    166
    Yes.

    The idea behind having the harness worked over is to eliminate wiring you simply don't need, and just getting it to the basics of what you need for the engine to run. It's easier and far cleaner, also allows for custom routing in a non-OE application.

    Also, if there is security protocol in the ECM, that is dealt with at that time, usually programming. The early stuff is basic and free of much of the later model features and far less integrated than the new. So you have that on your side.
     
    Rampart66 likes this.
  13. Rampart66

    Rampart66 New Member

    Joined:
    Jul 13, 2017
    Messages:
    16
    Likes:
    2
    Thanks for the information and the link to hotwireauto. Cleaning up the original harness sounds like a GREAT idea, and something I will definitely look into. Everyone has been so helpful here on the Allpar forum, and I appreciate all the comments and suggestions. Thanks!

    Rampart 66
    St. Augustine, FL.
     
  14. dana44

    Ad-Free Member

    Joined:
    Jun 17, 2002
    Messages:
    19,324
    Likes:
    1,236
    When I changed the engines in my two '95 Dakotas, the wiring was not that bad and not that large, either. What you do is isolate the wiring to the engine itself and identify which ones are not going to the engine, determine their purpose and label them. Some are external sensors and electrical pieces, determine which ones you need and which you don't need, including the fuse block(s) and relays, reduce what you don't need. Once that is done you will find the harness to easily fit in a milk crate (with space left over), the whole harness is about a 40lb bag of dogfood size (compared to a Ford truck wiring harness...two 32 gallon garbage cans, literally), so not that bad. Some of those wires off the computer are dash gauges, transmission and whatnot, and it will actually be easier than you think.
     
    Rampart66 likes this.
  15. Rampart66

    Rampart66 New Member

    Joined:
    Jul 13, 2017
    Messages:
    16
    Likes:
    2
    I know the wiring in my 1992 donor van is nowhere near as complicated as most newer vehicles, but is still a heck of a lot more complicated than the 1956 DeSoto that I rewired completely back in my younger years. Darn computers! I've been studying the wiring diagrams in my 1992 factory service manual, trying to get a feel for what I'm up against. I'm learning more and more everyday, thanks to the suggestions I'm getting from the Allpar forum members, and my "homework" here. Keep those thoughts and ideas coming. I REALLY appreciate all of them.


    Rampart 66
    St. Augustine, FL.
     
  16. dana44

    Ad-Free Member

    Joined:
    Jun 17, 2002
    Messages:
    19,324
    Likes:
    1,236
    Yeah, it's really not that bad once you start isolating everything, starting with the engine, identify each sensor and injector wire to the computer and mark them first, cuts the wires to identify down to about half, and 64 wires (or less) going to a computer is not so daunting when comparing it to three plugs with 62 wires each and a 128 pin computer in a similar year Ford Truck (now that's scary). The rest of the wires to the computer can be identified easily enough after that, such as scanner plug, gauges, fuel pump, barometer thingy, some trans wires, evap system (might as well keep that, goes with the fuel system stuff and is kind of needed these days), O2 sensors....you get the point. Best thing to do is see if the new van cluster can easily be adapted to the old van dashboard, which simplifies a lot of that wiring. Most of that wiring goes through a bulkhead connector and that would simplify all those wires, and upgrade your gauges to work without having to adapt anything (gauge and sensor and computer), and anything not going to that bulkhead connector, trace it to what it is connected to and mark it and remove it from its location, put a bag on the end of it to protect it. Do this to things that are not attached to the engine, like the O2 sensors or something connecting to the evap system, fuel system, where appropriate. If a wire goes from the computer to the bulkhead connector because it is going to the dashboard cluster, mark it and then for now remove the other connections (you have a diagram, but this decision is if you want to keep them in place in the event you wanted to upgrade the wiring to the headlights, etc., compared to the old wiring, but you get the idea.
     
    Rampart66 likes this.
  17. Rampart66

    Rampart66 New Member

    Joined:
    Jul 13, 2017
    Messages:
    16
    Likes:
    2
    The wiring sounds like something I can do if I take my time and be careful. Adapting the 1992 instrument cluster to the 1965 dashboard would be next to impossible, nor would I want to mess with the clean simplicity of the A-100's original dash. The A-100's, being a flat-nosed, mid-engined vehicle, are not your typical modern-day set-up. I'll have to see what I can do, and check out what other A-100 owners have done as far as upgrading. I'm heading to a big junkyard in a nearby town tomorrow for a handful of small parts and some research. I'll keep you posted!

    Rampart 66
    St. Augustine, FL.
     
  18. dana44

    Ad-Free Member

    Joined:
    Jun 17, 2002
    Messages:
    19,324
    Likes:
    1,236
    Not positive of the new Van cluster arrangement, but the Dakota is flat and about the same size as the old flat van clusters if I recall. That would ensure the gauges and sensors match resistance levels to be accurate. That is my big concern with them. And yes, take your time and it won't be that bad.
     
  19. Rampart66

    Rampart66 New Member

    Joined:
    Jul 13, 2017
    Messages:
    16
    Likes:
    2
    I'll take a look at the Dakota instrument clusters when I'm at the junkyard tomorrow. According to their online inventory, they have Dakotas from years 1987 through 2003, all with the 3.9 V-6's. I'll measure the gauge cluster in the A-100 before I go to see if there's something that may be close to fitting. Thanks again, dana44.
     
  20. dana44

    Ad-Free Member

    Joined:
    Jun 17, 2002
    Messages:
    19,324
    Likes:
    1,236
    You are welcome, just doing my part to help something cool out there.
     
    Rampart66 likes this.

Share This Page

Loading...