v-6 in early A-body

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BillGrissom said:
Read the Allpar site first. The Magnum V-6 was a quickie solution for the new Dakota pickup because the V-8 wouldn't fit. They later found room and dropped the V-6. Since they just lopped off 2 cylinders, it wasn't an optimal V-6 design and had vibration issues. I see them often in RAM vans at PicNPull. Seems Mopar often used surplus parts in later full-size vans and campers. But, the fact that it bolts up to a 1970-80's 904 style tranny is attractive, though you then lose the crank pickup and thus modern controls. It sure looks at home in an A, though to use its tranny may require re-fabbing the car's tunnel (true for V-8 Magnum). The Magnum V-8 engines suffer cracked exhaust valve seats, which might affect the V-6 as well.

The 3.8L V-6 is a better design, having a 60 deg V angle, so much less vibration. It was used in minivans (my 2002 T&C), but a better source is the RWD version used in Jeeps. Some Jeepers deride it as "a minivan engine", which seems silly. The FWD versions may be missing some motor mount holes and the intake ducting may not work. Not sure what tranny the Jeeps used, but they long used Mopar trannys. Look for a 2WD Jeep. The 3.8L is still a push-rod design, so might still fit under an A-body hood, though the shallower angle makes it sit taller than a Magnum. Indeed, the rockers and shaft look like in my 65 383 engine. Speaking of that, get a later one. They added a rocker post to the head since early ones suffered cracked posts. The 3.3L is almost identical, but I don't think a Jeep version. The Engine Builder site has a great writeup on the variations.
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I completely disagree with 98% of your post. First, they didnt drop the V6 when they had room for a V8. The Dakota had both and still does, as well as using them in Rams and unmentioned Durangos. The Magnum 3.9's were excellent engines for small trucks and 2wd 1/2 ton trucks if you didnt haul heavy loads. They got great MPG and were super reliable. I have worked on hundreds of them over the last 20 years of running a Magnum Performance shop and have never had a complaint about vibration. Third, your comment about loosing crank trigger is WRONG. Its easy to run factory injection with a 904 or 727, you simply have to notch bellhousing for crank trigger and use magnum flywheel. I have done this in CJ Wranglers and currently have a 65 Dart running 904 as well as a 67 Dart GT Vert we just installed 5.9 in , all with injection. There is some cross member modification to fit a 44/46 RE in a 67+ and some additional floor mods on 64-66 but the 67+ are not hard at all. That was the only part of your post I agree with and was wondering have you ever done the swap? Have you ever owned a magnum engine? The Allpar article was written from a point of author not liking his 3.9 van and in the end of article it even mentions issues form bad O2 sensor and CPM sensor causing rough running and drivability issues....in other words he just vented his dislike of 3.9 by bashing earliest design which nobody uses. Here is another interpretation of 3.9
Magnum 3.9L[edit]
As the 5.2L V8 was introduced in 1992, the often-forgotten V6 version of the Magnum engine became available in the Ram pickup and the more compact Dodge Dakota. Based on the LA-series 239ci V6, the 3.9L featured the same changes and upgrades as the other Magnum engines. The 3.9L can be better understood by imagining a 5.2L V8 with two cylinders removed.

Power increased substantially to 180 hp @ 4,400 rpm (134 kW)and from 195 lb·ft (264 N·m) to 220 lb·ft (298 N·m) @ 3,200 rpm, as compared with the previous TBI engine. For 1994, horsepower was reduced to 175, mostly due to the installation of smaller-volume exhaust manifolds; torque ratings remained the same.[5] For 1997, the 3.9L engine's torque output was increased to 225 lb·ft (305 N·m), with a compression ratio of 9.1:1.[5] Firing order was 1-6-5-4-3-2.[5] This engine was last produced for the 2003 Dodge Dakotapickup. Starting in the 2004 model year it was entirely withdrawn from production and replaced with the 3.7 L PowerTech V6 engine.[14]

A much more objective description in my opinion. I also disagree on your mini van engine. If you have ever driven a 3.8 JK Wrangler, they suck! No torque, wrong powerband for Jeep and get horrible MPG. They would have been much better off with the 3.9 or 3.7 anthough I am not a 3.7 fan, it would have at least made it easy for latermodel 4.7 swaps. You only option now is Hemi.
BTW hacking 2 cylinders off a V8 was also done on GM's VERY popular 4.3L V6 which shares 5.7 GM parts as the 3.9 to 5.2 does. Its been succesfully done for years quite successfully, the Mopar version just isnt as famous.

OP it will be a great swap, just stick to 1996+. CJ Jeeps are not much heavier than an A body so it will be fun economical and still spin the tires!
904 trans notched for Crank Sensor
transnotch.jpg

5.9 showing Crank Sensor bolted on.
cranksensor.jpg

64 5.2 44RE pre fit and 3.9 is much shorter than this!
64 5.244RE.jpg

V8 harness ready for install, V6 is almost identical.
hotrodharness.jpg
 
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I had to have 5 timing chains put in my 92 Dak before 100,000 miles. The last one was installed at 115,000 and was the first time the dealer installed the chain tensioner. It was fine at 200,000 when I sold the truck.
I wouldn't hesitate to use the 3.9 at all, it would be a blast in a early A.
 
Bobscuda67, interesting on the frequency of timing chains before 100,000. The original on mine I changed at 175,000. The second one the new tensioner failed and the top of it slid off it's tab pushing the new chain against the oil drip tab. Replaced that set and it happened again after 1000 miles. Replaced oem style chain with cloyes racing double roller and took the tensioner off due to the design of the chain links I thought it would eat the tensioner up. Have run that double roller chain for over 100,000 miles now as my truck has 288,000 miles and still averages 20 mpg. Never did understand how the tensioner kept failing and slipping off its tab.
 
On my 340 I used the chain tensioner with the Cloyes double roller chain and it wears 2 little grooves in the guide until it hits the rollers. I have always wondered about that, as the tensioner was made to ride on a factory silent chain.
The factory timing chains were made by the lowest bidder with the cheapest steel. That might have something to do with it also.
 
We have pro gear chains in several different levels, lowest is roller with cast upper gear and best is with billet gear and 9 timing choices. never used a tentioner since we got these. Made in USA is the way to go.
 
I have 2 96 Dakotas and one 2000 and both the 96's have noisy timing chains. One with 140,000+ an the other just at 100,000 miles. They must have fixed that in 2000 because that one has 160,000+ and its quiet.
 
My first 5 chains were under warranty but when I took it back at 115,000 they charged me $400 to fix it. It's then when they installed the tensioner that finally fixed it.
I was pissed that I had to pay for it I called Chrysler and they refunded my money.
 
To the original post : yes it is possible and as mentioned someone had a great wagon with one. The 3.9L Magnum I had was a nice torquey engine, my '97 Dakota was super easy to drive with the manual, I could put it in any gear & almost drive it like it had an auto trans. But why bother to go to all the trouble when for the same effort you could have a 5.9 V8?
 
Economy....you wont get 25-27 mpg hwy with a 5.9. Cost is another issue as 400+ HP will require 4 wheel disks, larger rear diff,beefed up trans, larger radiator, electric fan etc.
SSVDP what mpg did your Dak get on frwy, mid 20's?
Considering a 3.9 is about 100 hp and 100 ft lb torque over a /6, thats a huge improvement for the price of /6 header, cam and intake/carb and you end up with injection for daily driveability , which a 5.9 would also have.
 
SSVDP said:
But why bother to go to all the trouble when for the same effort you could have a 5.9 V8?
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Why follow the V8 crowd. Be different whether it's a 3.9 V6, or a slant 6, or a Jeep 4.0L or a 4 cylinder diesel as other members are doing.
 
I get the same question about using 5.2's in some of our Darts, why not a 5.9? Well, I have never gotten 20+ mpg with a 5.9 in anything but a 5.2 will pull mid 20's easily and they rev much quicker. A mildly built 5.2 will make 325-350 HP which is more than a 360LA made without lots of work. A 64 Dart with 300+ HP is plenty fun to drive and will get you a nasty ticket or incarcerated at half throttle. Its all relative, living 10 miles from town makes it an easier choice too, running errands doesnt require 400 hp so my daily driver choice would be small cubes while my fun toy would be big cubes and LOTS of power. I also have 9mm and 357's, the right tool for the job.
 
I would drive a Chebby before I put a 4.0 in anything Mopar, I have spent the last 18 years taking 4.0's OUT of vehicles for the very same reason I would not put one in....its a tractor engine designed in the 50's that makes poor power, crappy MPG and has no top end. Same for diesel, in a heavy vehicle they might be tolerable but in a light car the power is all wrong, both are done making power at 3K and you certainly dont need to move torque curve low enough to spin tires at 1200 rpm but run out of revs before the top of the on ramp. Freeway driving kills either of those engines and without overdrive both would be miserable. Ever drive a Jeep 4.0 on freeway? There is a reason why my Jeep Magnum swap is so popular, real power, better MPG and overdrive.
 
I was with you till you ragged on 4.0 Jeeps. I've owned several Cherokee's That have run well into the 300K miles range @ 21-23 MPG. Plenty of power, I don't know how it could have been better!
 
I didnt say they were not reliable, just that they were a tractor motor, not made to do anything above about 3K RPM. They served their purpose in a Cherokee but the thought of putting one in a Barracuda is a capital offense to me. I have owned over 10 Wranglers over the last 18 years and never felt the 4L love...once you put larger than stock tires on they get 12 mpg. The Cherokee was the best application of that engine they had....I had one in 94 XJ that was at 270K when I sold it, primarily a ski vehicle which it did well as long as you were happy at 67 mph on freeway. My comment was not intended to bash the XJ, it was pointing out what a bad idea putting one in an A body was right along with a 4 cyl diesel. Its like making Cindy Crawford wear a fat suit and mumu, its just wrong.
 
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you can put a turd in a taco and somebody will eat it....getting back to 3.9 in an A body, who wants to be the first guy on the block to drop one in? How about i put my money where my mouth is and offer a severe discount on a harness to the first guy that gets serious. You will have to install the engine first and send me pics of it ready for harness and I will knock a few hundred off the harness just so everybody can see how cool it will be to drive....say instead of $600(my everyday FABO discount) how about $400? I will even throw in full tech support for whole swap and a better than normal deal on the rest of the parts......any takers? You should be able to find one for dirt cheap with harness and pcm. Only stipulation is it has to be OBD II so we can flash pcm.
 
Thanks for the input everyone, I think I will be on the lookout for a 3.9 v-6 now for my 64 GT. I am not sure that I would want to go with fuel injection though, I guess that I am not that familiar with FI and if I am doing this, I will be doing it by myself, just like when I took the pushbutton out and installed a 3-speed on the floor. Now I am removing the 3-speed and installing a 64 A-833 in the car that I completely disassembled and rebuilt, never having taken one apart before. I am looking forward to this swap and would greatly appreciate all the advice I can get on the subject. I will try and remember to take pictures as I go along. And thanks again Evan, I just might take you up on that offer.
 
If possible, find a wrecked but running dakota. Take everything, fuel injection, wire harness, computer, fuel pump. It will run so much better, power and economy with factory fuel injection. If you find a dakota with a manual, take the master cylinder with it.
 
I would not do it if I didnt run injection as the choices for small 4 bbl carb are very limited. FI is super easy, dont really need to know much about FI to swap FI engine into vehicle, my harnesses require you hook up less than 6 wires. Batt, Ignition start/run, ground, fuel pump and thats about it. If you have a good running donor, pull it out, install it in 64, hook up fuel lines, throttle and let her rip. The harness comes with complete tech support for whole swap too. Find a donor and I will walk you through it...
 
racerdan80 said:
If possible, find a wrecked but running dakota. Take everything, fuel injection, wire harness, computer, fuel pump. It will run so much better, power and economy with factory fuel injection. If you find a dakota with a manual, take the master cylinder with it.
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Its not worth pulling fuel pump as its beyond a pain to install in A body tank and the sender wont work with A body gauges, also there is no fuel filter on that system which and metal tank system needs. The tanks inc EFI tank is a much better option as its a better design, wont leak below fuel level, has baffles and the gauge sender works like stock did. I did a factory pump in one 12 years ago because Tanks Inc didnt make that tank yet and let me tell you, unless you are used to working for $2/hr just get the Tanks stuff....
 
Thank again. Right now I am going out to try and get my tranny swap started. When that is done, then I will see about finding a motor and all that other stuff. Stay tuned.
 
magnummopar said:
Its easy to run factory injection with a 904 or 727, you simply have to notch bellhousing for crank trigger and use magnum flywheel.
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I am curious about the crank trigger, and what it looks like. I do not understand "magnum flywheel", in relation to 904 or 727 unless that is starter ring gear, and I assume different for V6 and V8. If a picture of trigger "target" is available, it will help me greatly.

I think it might be possible to generate the crank trigger signal from the distributor with the addition of a second sensor and trigger there. At the same time, the ignition could be done direct fire, coil on plug. I can use same hardware I am developing for the V8 COP ignition. I designed a similar system for 2.2L engine, and used the OEM ECU for timing control, diverted to coils. The reason would be easier drop-in eliminating crank sensor and bellhousing mod. The EFI trigger would come from my ECU associated with ignition.

I like the idea of the V6 it removes weight from front, providing better handling balance.
 
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KitCarlson said:
I am curious about the crank trigger, and what it looks like. I do not understand "magnum flywheel", in relation to 904 or 727 unless that is starter ring gear, and I assume different for V6 and V8. If a picture of trigger "target" is available, it will help me greatly.

I think it might be possible to generate the crank trigger signal from the distributor with the addition of a second sensor and trigger there. At the same time, the ignition could be done direct fire, coil on plug. I can use same hardware I am developing for the V8 COP ignition. I designed a similar system for 2.2L engine, and used the OEM ECU for timing control, diverted to coils. The reason would be easier drop-in eliminating crank sensor and bellhousing mod. The EFI trigger would come from my ECU associated with ignition.

I like the idea of the V6 it removes weight from front, providing better handling balance.
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Post 26 First and second pic show both notch for sensor and sensor mounted on block. The OP was discussing using a A-833 manual trans which would require a 134 tooth flywheel with reluctor on it because the Magnum flywheel is 140 T and too big for A-833 bell housing.
It literally takes me 10 minutes to modify bell housing and sensor is already mounted to back of block. the stock flex plate will bolt right up to early converter if you clearance one bolt hole 1/16". I see no reason to reinvent the wheel, Chrysler spent a zillion dollars in R & D developing it and it works great, doesnt fail and already there. I also like the availability of parts, in the rare occurrence of a part failure, the sensor is 96-03 3.9/5.2/5.9 Magnum available at 7-11 for $38 and I have literally seen maybe 15 failures in 18 years of daily magnums, coil is $35 stock or $50 for MSD. The thought of dual magnetic pick ups in one distributor sounds like trouble to me....1979 Datsun 280Z brings back nightmares even in the daytime....
 
I remember when my 92 Dak had the oil pump drive bushing wear out my truck would barley run at all. After I replaced the bushing
you had to reset the distributor with an ohm meter.
My 92 had the big hole exhaust manifolds and was pretty loud, and the later years had the smaller manifold.
I guess that's why mine was rated at 180 hp and it went down to 175 after 93 I think.
 
magnummopar said:
Post 26 First and second pic show both notch for sensor and sensor mounted on block. The OP was discussing using a A-833 manual trans which would require a 134 tooth flywheel with reluctor on it because the Magnum flywheel is 140 T and too big for A-833 bell housing.
It literally takes me 10 minutes to modify bell housing and sensor is already mounted to back of block. the stock flex plate will bolt right up to early converter if you clearance one bolt hole 1/16". I see no reason to reinvent the wheel, Chrysler spent a zillion dollars in R & D developing it and it works great, doesnt fail and already there. I also like the availability of parts, in the rare occurrence of a part failure, the sensor is 96-03 3.9/5.2/5.9 Magnum available at 7-11 for $38 and I have literally seen maybe 15 failures in 18 years of daily magnums, coil is $35 stock or $50 for MSD. The thought of dual magnetic pick ups in one distributor sounds like trouble to me....1979 Datsun 280Z brings back nightmares even in the daytime....
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Please forgive me about my lack of knowledge on this. Now I think I understand it is the flex plate, that has the tone wheel that goes with the crank sensor. I do not see that in pictures on post #26. I will see if I can browse for an image online.
 
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