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MoparFreak69 04-09-2010 09:43 PM

V-8 Conversion process started
So I finally decided that instead of replacing the head gasket on my wimpy 4 banger I am going to begin my build up of a 318/360 to swap into my Jeep.
I picked up a MPI manifold from a local pull-a-part today for $45, which included most sensors and injectors/fuel rails. Got manifold that does NOT have EGR port, less to screw with getting it together.
I picked up the engine wiring harness from the same rig (96 Ram 2500 w/5.9) to use as a donor/splice harness for $30.
Here are my plans to date:
Use my LA block 318 out of my 68 Dodge Dart as my base engine (have it laying around not being used anyway).
Modify the heads to accept the Magnum style intake I picked up (basically just redrill the mount bolt holes) and put EFI on it.
Get distributor from MPI engine for crank/cam position sensors and to complete EFI system.
Find/buy a VSS adapter from 91 YJ for my speed sense for the PCM.
Use whatever accessory bracket system I can come up with that will serve my purpose (prefer the serpentine system that Magnum v-8's have but will see what funds decide for me)
Pick up a Bellhousing/flywheel/pressure plate/clutch disc (last 2 depend on condition) from a mid 90's 2wd Dakota w/ 3.9 V-6 and AX-15. This gives me the ability to install an NV3550 later on easily and should have the external slave cylinder which is more desirable.
Get pilot bearing for a YJ w/4.0 (Diameters are almost perfect for the old 318)
Use HD radiator from YJ w/4.0.
Build my own mounts from steel (will use old LA mount spots as Magnum engines still have these; that way I can always swap in a real Magnum 5.2/5.9 later easily if I feel so inclined).
Pick up PCM from manual transmission truck to avoid auto headaches.
I will locate and use an AX-15 and 231 TC from a Cherokee as my transmission of choice for now. I have 2 reasons for this: 1st - Immediate price and availability and 2nd - If it fails then I can locate a 3550 and swap it in with very minimal troubles.

Building my own custom mounts will allow me to place the engine wherever I want, thereby allowing me to make the swap without changing driveline lengths right now. I will be doing a SYE kit sometime in the distant future, cannot afford it now so no use changing lengths twice right?

The wiring should be taken care of with the truck harness I have and using the majority of the existing YJ 2.5 TBI harness.

Any thoughts of stuff I am missing here?

I am on a tight budget but am more than willing to make a part I need vs buying one. I have a cheap pull-a-part yard around (actually like 4 of them) where I can get pretty much everything I will need.

Keeping the stock Dana 30/35 combo w/4.10 gears for now. I wont be doing any hardcore offroading this year and the Jeep will only see daily driving use which I can handle keeping my foot out of the go pedal until I can afford to put a Chrysler 8.75 or Dana 44 axle out back w/air lockers in both.

MoparFreak69 04-09-2010 10:12 PM

Just for FYI if anybody else is consider this/a similar swap:
These vehicles are your donor choice for the VSS adapter for the speed sensor signal to the PCM.
The NAPA PN is VSS 110
Dodge Truck D100 1/2 Ton - Pickup 1988 - 1989
Dodge Truck D150 1/2 Ton - Pickup 1988 - 1989
Dodge Truck D250 3/4 Ton - Pickup 1988 - 1989
Dodge Truck D350 1 Ton - Pickup 1988 - 1989
Dodge Truck Dakota 1988 - 1993
Dodge Truck RamCharger-AD100 1/2 Ton 1988 - 1988
Dodge Truck RamCharger-AD150 1/2 Ton 1988 - 1989
Dodge Truck RamCharger-AW100 1/2 Ton 4WD 1988 - 1988
Dodge Truck RamCharger-AW150 1/2 Ton 4WD 1988 - 1989
Dodge Truck W100 1/2 Ton 4WD - Pickup 1988 - 1989
Dodge Truck W150 1/2 Ton 4WD - Pickup 1988 - 1989
Dodge Truck W250 3/4 Ton 4WD - Pickup 1988 - 1989
Dodge Truck W350 1 Ton 4WD - Pickup 1988 - 1989
Jeep Wrangler 1991 - 1993
Jeep YJ 1991 - 1993

bmgadg 04-09-2010 10:45 PM

Will be watching this thread!!

I have a magnum efi 5.2 from a 96 that's waiting to be rebuilt and installed. I plan to do the same thing as you with the transmission... ax-15 with dakota bellhousing and all. I've read somewhere that the stock 4.0 jeep clutch and pressure plate will work on the dakota flywheel. Anyone know if this is true?

Looking forward to seeing your progress, post plenty of pics!!

bmgadg 04-09-2010 10:48 PM

Also, are you sure that pilot bearing is going to work with the 318 crank? I read somewhere that a guy had to have a custom bearing made for his swap.

MoparFreak69 04-10-2010 12:52 AM

The stock pilot bushing for my motor is .9353" outside diameter. The 4.0 pilot bearing outside diameter is just a hair under 1" so I will have to have my crank machined out slightly. This isnt a big deal to me as I don't have the engine final assembled anyway, its coming back apart for honing, cleaning up and assembly lube before it goes back together.

You do need to pay attention to whether or not your crank has a hole for the pilot in the first place. I believe all the Magnum motors have the hole machined already, but should check before you start to get too deep into the project. Removing a crank from a rebuilt motor is a pain in the butt!

MoparFreak69 04-10-2010 01:01 AM

As to the stock 4.0 stuff fitting, unsure but I will look into it. I will probably try to get a new pressure plate and disc if I cant find an excellent shape used one. I will just order one for the 2wd <(I believe this is important to remember) Dakota with the 3.9 V-6 and the AX-15. Once again as I progress I will research things more closely and update with findings. So far have removed about 20 wires from the harness and more to come. I am paring the harness down to just what the engine needs to run properly. Basically what will be left is: TPS MAP Air Intake Temp Sensor Idle Air Speed Motor Coolant Temp Both O2 sensors Crank Position and Cam position sensors Coil Power Injectors VSS Tach output to Jeep 12V Batt and switched into controller Need to make my own relay system for Auto shut down and fuel pump MIL (gonna make my emission lamp do that duty) Ground Basically that seems to be all that the system needs to run properly. After I get things together and going I will draw up a wiring diagram for future reference for myself and anybody who wants to take on this task. Its fairly easy, but can seem overwhelming when looking at all those wires!

bmgadg 04-10-2010 06:28 AM

Awesome information! My crank is already machined for a pilot bearing, but has an auto flywheel on it now.

I haven't even started looking at wiring yet. I do have a complete odb1 harness and computer already, but the computer is out of an auto. I'm hoping I don't have any problems with that. I've heard that odb1 is much more forgiving than odb2.

I'm going to keep a log of my progress too for future reference since there isn't a wealth of information on this swap.

Roadyy 04-10-2010 07:23 AM

Ok I'm intrigued and subscribed. Sounds like a fun build.

MoparFreak69 04-10-2010 12:37 PM

I actually have a truck that I can use to test my wiring out on when I get everything all set up and find a PCM. My dad has a 97 Ram 2500 with a 5.9 that I will be able to use. I will basically disconnect all of his wiring from the sensors and injectors and disconnect the battery from the truck so that nothing of his is being used. I will then plug my harness onto his engine and hook up my wiring to necessary connections (ie constant power, switched power, fuel pump, etc). I realize I will still need the starter wired up and will have to make a remote start connection so that I can get it cranked over. This way I start with known goods (sensors) and if I have any running issues can narrow down to what part of the wiring isnt cooperating. This will probably be about 2 weeks out so that i can have the time to finish my wiring mods and have a chance to drive to my parents place and do everything. If successful I will take some pics of my harness and draw up a diagram. That will be the absolute biggest hurdle in this conversion and if I can get that out of the way I am halfway there.

MoparFreak69 04-11-2010 11:04 PM

Small update but figured I would mention it here. I decided to go ahead and pick up the Magnum style heads to put on my LA engine block. With the exception of having to buy new lifters and special length push rods (Mopar Performance has these in a kit) for around $120 plus the $60 for the heads I cant have mine rebuilt and machined to accept the MPI intake I picked up. I just hope the heads are in good shape, however I dont imagine the truck was in the junkyard because of engine troubles.

I have located a donor bellhousing, just need to check out what kind of throwout setup it has. I will try to snag it from the rig some time during the week.
Guess I need to get my cherry picker from my old man soon so I can get the block off the stand and do some fitting with it.

MoparFreak69 04-14-2010 09:25 PM

Another small update. Wiring harness has been hacked down to bare minumum needed for running. I will hopefully be testing this next weekend on my test bed truck to ensure it will support engine running.
Cleaned and inspected my Magnum heads. Aside from one valve needing cleaned up a bit, they are ready for running.
Progress to date: Good heads and intake sitting on known good block (good long block to work with). Wiring harness paring down has been completed. I have half of the necessary sensors for the engine, have all the injectors and fuel rail. Searching yards for rest of parts necessary to get engine to fire up and run.

Getting antsy to hear an engine run on my harness, that will be the largest part of the battle won. The rest is just bolt together. After getting a running engine I will draw up and post a diagram for anybody who may be considering this swap or something similar. With a big of inginuity and a little engineering, this system should be able to be run on ANY V-8 (ie AMC 360 anyone?)

stoveguy01 04-14-2010 09:45 PM

you will love this eng, I just put a 94 5.2 and 4 spd auto out of a 94 GC into mine last month and its been awesome I love it:cheers2:

MoparFreak69 04-22-2010 05:36 PM

Another update, this one quite a bit more important than the last. I picked up an AX-15 and 231 Transfer case from a 92 Dakota for $225!!!! I need to go pick up a bell housing and flywheel which will run me about $50 and I have the drivetrain pretty much taken care if. It came with shifter for both trans and transfer case as well as the throwout bearing and fork. This setup used the external slave cylinder so its even the highly desirable one!

WAHOO score one for the home team. Looks like I am better than half way there!
Checklist of things needed is getting quite a bit smaller.
Still need:
PCM ($100+/-)
Distributor ($40 if I can find a complete one in the yard)
Throttle Body w/sensors ($50 +20 if I can find good sensors)
Bell Housing ($30 - already know of a couple just need to pull it)
Flywheel/Clutch ($20 for flywheel, slightly more if I find a good pressure plate setup)
Trans Mount (Can probably modify mine if needed, if not $5 at yard)
Alternator and Power Steering brackets (very cheap and readily available)
4.0L radiator
Electric fan
and then just a few parts and pieces.

Looks like I am staying well within my newly shrunk budget! Getting excited!

MoparFreak69 04-26-2010 08:47 PM

Another update!

The Dakota 231 has a longer output shaft than the Jeep. I took both apart and used the front half of the case from the Dakota and stuffed the Jeep internals and rear cover (except the rear shift fork retainer part) so that I could keep the vacuum switch on the front of the t-case instead of moving it to the back.

Picked up a bell housing, flywheel, pressure plate, clutch disc, clutch slave cylinder,Throttle body complete with sensors, PCM, clutch fork with TO bearing. All for a penny under $120!!!!!

Note to anybody looking to do a swap similar to this:
Find a 90-95 Dodge Dakota with a 3.9 V-6 and a 5 speed. It will have the AX-15 transmission and the correct bell housing to fit a V-8 up to the transmission and make everything blend together like puddin!

I snagged the PCM out of a 96 Van with a V-8 simply because it was the only one laying around and it was a whopping $10! Looks like next weekend is the test run for my stand alone EFI system on the test mule. Only thing I gotta figure out is how to power the fuel pump in the truck without affecting any of the other wiring.
After that, I promise wiring diagrams for all the little boys and girls of this forum!

MoparFreak69 04-26-2010 09:50 PM

Here are a few pictures showing progress and a few discovered obstacles:

Being a 6 cylinder flywheel, there are only 6 windows (3 double, 3 single) for the crank position sensor to detect. This picture shows the locations of where the 8 cylinder windows needs to be (in yellow), and where they will be relocated (what can I say, im cheap, I will grind them out myself):

Here is the trans and tcase sitting together waiting to join the motor:

LA block (circa 1973) w/ Magnum heads and MPI intake (1996):

Front view of the motor. Still filthy but will be thoroughly cleaned before final assembly and installation:

I removed the air horn (which I also picked up today) showing the throttle body sitting on the intake. Everything for the EFI is accounted for but distributor (coming tomorrow) and Crank Position (modding the tone ring tomorrow and picking up sensor tomorrow also):

And finally a shot of the rough wiring getting ready to be put on my test mule for a test run next week:

What do you think so far?

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