Jump to content


Garage Vehicles

Disney Pics 003.jpg

Jeep Wrangler (1992)

Owner: Megatron

Added: 27 September 2013 - 08:56 AM

20131023_113518.jpg

Dodge Ram 3500 (2006)

Owner: Megatron

Added: 25 September 2013 - 07:37 AM

6-inch XJ suspension lift (Lead).jpg

Jeep XJ Cherokee 4WD Sport 4-door (1999)

Owner: Moses Ludel

Added: 15 September 2013 - 01:16 PM

1988DodgeDakota.jpg

Dodge Dakota (1988)

Owner: biggman100

Added: 22 September 2013 - 05:22 PM

Forum Photos (2).jpg

Dodge Ram 3500 Cummins Quad-Cab 4x4 S...

Owner: Moses Ludel

Added: 15 September 2013 - 08:42 AM


Photo
- - - - -

Dodge Dakota Hemi Swap

Dodge 4WD truck

  • Please log in to reply
12 replies to this topic

#1 Flynaround

Flynaround

    Member

  • Members
  • PipPip
  • 3 posts

Posted 18 August 2014 - 07:21 AM

My 2006 Dakota quad cab 4x4 has 150k miles on it and is in need of a torque converter. The dealer won't replace it without replacing the tranny also. $4900 is their price. Instead of spending that on a transmission, I would rather install a hemi and do away with the V6. I get 16.5 mpg highway and 8.5 mpg towing a 3700lb boat in Oklahoma. I also have a 2009 Ram 1500 back in Denver with a hemi that gets 21 mpg and 14 towing my boat. So I am looking to install a V8 hemi with a comparable transmission & transfer case. I see wrecked trucks in every state so finding a used complete package is easy. I just want to know what year of combination package should I look for? Will a Ram 1500 hemi, trans & transfer fit? I know I may have to change drive shaft lengths but will I need to fabricate different mounts for the transmission and engine? What problems will I need to address? I don't really need the 390 horses but it should get over 21 mpg. Or is there a better V6 with more power and better gas mileage? I could have my 42RLE trans rebuilt with heavier parts. Or even rebuild the V6 with forged parts and turbocharge it. Just worried about too much heat when towing. Also, reflashing the computer to sense manifold pressure. What would be your suggestion to gain mph and a little more power? I use my Dakota to drive from Oklahoma City airport to lake Eufaulla, about 120 miles. My boat stays at the lake so I only tow it sometimes to visit another lake. Also, do you know anyone that will do the conversion for me. I don't have the time, I'd rather be playing on the water and pay someone. Please help, mike

#2 Moses Ludel

Moses Ludel

    Administrator

  • Administrators
  • 1,117 posts
  • LocationReno Area...Nevada
Garage View Garage

Posted 18 August 2014 - 03:37 PM

Here's a place for fellow member Biggman100 to comment!  He's explored the differences between the V-6 and V-8 models, and we have discussed changeovers.  I have the factory parts listings and pictures through 2008, which will apply here if it comes down to an actual need for specific part numbers.

 

I'm always focused on the chassis and wiring differences, PCMs, the harnesses and such.  My first fling at this kind of swap would be lining up your Dakota alongside a V-8 model.  The factory option is the 4.7L V-8, so this goes even further with comparisons between the 4.7L V-8 and 5.7L hemi engines.  If it gets down to individual parts, I can provide Ram 1500 comparisons between the 4.7L and 5.7L applications.

 

This can be done, it's a question of how many parts and how much effort to bring the engine, transmission, transfer case and drivelines to spec.  You mention drivelines, and this is the least of it, as a good driveline shop can bridge any length, mounting or joint issues.  The gray area is usually transfer case type and shift linkage, powertrain mounts, speedometer and VSS issues and that sort of thing. 

 

Let's see what Biggman100 has to say, and I'll share from my angle, too.  I'll drop a note to Biggman100.

 

Moses



#3 Moses Ludel

Moses Ludel

    Administrator

  • Administrators
  • 1,117 posts
  • LocationReno Area...Nevada
Garage View Garage

Posted 19 August 2014 - 08:09 AM

As a footnote, flynaround, there's a limit to working a chassis and powertrain.  The 2006 Dakota has specific capacities for pulling a trailer.  I'd look at the V-8 Dakota model specs and see what Chrysler had in mind for loads on this vehicle.  Tow capacity includes brakes, powertrain, suspension, wheelbase length, track width and frame stamina.  If any of this is subpar on the Dakota when compared to your towing plans, you might consider selling your popular Dakota and either using the Ram 1500 for towing or finding another appropriate chassis for your towing chores.

 

For towing, you can't have too much truck, but you can have too little.  I like our Dodge Ram 3500 4WD Cummins truck for towing and have never reached gross vehicle weight or gross combination weight.  That's my plan, as I want this truck to see a half-million miles of service.

 

Moses



#4 biggman100

biggman100

    Advanced Member

  • Members
  • PipPipPip
  • 230 posts
  • LocationNew York
Garage View Garage

Posted 22 August 2014 - 05:46 PM

Sorry for the delay in responding. I have been away from my computer for awhile now. Before i begin getting into the swap, i want to say, i dont want to discourage you in any way, but this swap is a major undertaking, and, if this vehicle is registered in a state that does emissions testing, wouldnt be feasible, due to the PCM not being native to the dakota, and the VIN and mileage not matching. There are a couple places that i know will reflash the 2001-2004 PCM, but it is extremely pricey, and they let you know right up front that they are not responsible with any driveability issues with it once it is reflashed. If emissions arent an issue, then it is doable, but it very involved.

 

You will, at the very least, need the entire wiring harness from the donor vehicle. And, by entire harness, i mean engine, interior, lighting, the whole thing, being that the dakota and ram wiring are not compatible with each other, which means you will have to do custom wiring for the dash and interior components, as well as mounting any switches the dakota doesnt have.

 

You will also need a custom drivers side engine mount, because the dakota mount bolts up differently, and the passenger side only uses 3 of the 4 mount bolts. The drive shafts will also need to be custom made, due to differences in length and yoke and u-joint diameters. The biggest downfall though, is the HP difference. The Dakota's frame wasnt built to handle the kind of power the HEMI puts out, not even the smaller 5.7. The HEMI puts out, at a minimum, 100 HP more, and at least 100 LB-FT of torque more than the 4.7, which translates to the brakes ending up not being adequate for the swap.

 

There are other things im sure im forgetting here, mainly because i have only seen one of these swaps done, and that was on a drag truck, and not a street vehicle, so things like exhaust and transmission mounts were custom made for that specific swap. All in all, it is a doable swap, but with the cost and time involved, as Moses said, it might be better to sell the v-6 Dakota, and buy a v-8 dakota or Ram, or, another option may be to find an independent shop, and see if they will do just a converter swap, or even a used transmission for less than the dealer quoted you. If you do decide you want to go ahead and tear apart your truck for the swap, and need any help, feel free to ask. If i dont have an immediate answer, i will get the correct answer to you within a day or two.



#5 Flynaround

Flynaround

    Member

  • Members
  • PipPip
  • 3 posts

Posted 23 August 2014 - 06:10 PM

Thank you so much for all the knowledge. A few reasons I wanted to keep the Dakota. It's paid for, it fits in the garage with the boat, a full size won't, my boat only weighs 3800 lbs with trailer and I need the gas mileage more than anything and thought the lighter truck would be the ticket. However, the wiring and other things you mentioned sound like more headache than I need. I drive 260 miles round trip from Oklahoma City airport to the lake 4 times a month. Since the boat stays at the lake I am more concerned about gas mileage getting there. I may do as you suggest and buy a full size pickup to accomplish better gas mileage. Do you have any insight on what might be done to rebuild my 3.7 V6 to make it get better gas mileage? Either naturally aspirated or turbocharged or supercharged? I am not looking for extreme power. Just better gas mileage with a little more towing power. 50 more horses would be enough. It won't hurt my feelings if you tell me the 3.7 is junk. That would actually help me decide to buy another truck. Mike

#6 biggman100

biggman100

    Advanced Member

  • Members
  • PipPipPip
  • 230 posts
  • LocationNew York
Garage View Garage

Posted 24 August 2014 - 12:13 AM

On a 3.7, 50 more horses might be a stretch, without internal engine work. With a matched freer exhaust, underdrive pulleys, and electric fan conversion, Royal Purple fluids, and an add on performance chip, all done to a friends 2005 3.7L Dakota, he had a verified 10HP increase, which, for the work, time and money involved, didnt seem worth it to either of us, so, he ultimately traded it in on a 2007 Ram, with a 5.7L Hemi, and he said not only does he get better MPG, but has more towing power, and a higher towing capacity, than his Dakota had. The trade off there though, is cost for certain types of maintenance is higher, for example, there are 16 spark plugs in the 5.7, and 6.1 Hemi engines, and they require at minimum double platinum plugs, so that makes just changing the plugs more than double the cost in your Dakota.

 

The 3.7L, and the 4.7L, are both decent engines, but, just like any vehicle, maintenance, and how it is performed, and when, will make a huge difference in how reliable a vehicle is. The reason i bring this up, is i have heard a lot of stories of the 3.7, and even more stories of the 4.7 failing prematurely, but, when you dig deeper into those stories, a lot of them are guys who figure maintenance is something to be done when the vehicle has an issue, and not before, or, done very sporadically. A perfect example of this was a guy i knew who waited 20,000 miles between oil changes, and then wanted to sue chrysler because his jeep died with 62,000 miles.

 

I want to addres the idea of supercharghing, turbocharging, or leaving it naturally aspirated in this way. I have never turbocharged or supercharged a truck of any kind, but, i build Subaru rally cars, and one thing that i know is that when you add that much extra air and power to a Subaru engine, if you dont lower the compression, it is a recipe for disaster, and the engine wont last very long. I will be honest and say that, although i build turbocharged Subaru cars, i am not sure of what the reasoning behind lowering the compression is, but, i do know the one time i put a turbo in a naturally aspirated Subaru, it blew the bottom end apart in less than 100 miles. Maybe Moses can chime in here with some more insight into that. My thought on that though, unless Moses, or some of the other guys here have some more insight into it, would be not to add a supercharger or turbocharger, unless you are certain that engine could hold up to the added power without damaging it. I know turbo kits are fairly expensive, and when you factor in the cost of a turbo or supercharger, only to have to replace the engine due to the added stress, in the long run, the cost of a 5.7, or even a 6.1 Hemi Ram might ultimately be cheaper. Plus, from knowing what the turbo in the Subarus i build cost, there isnt really enough of a fuel mileage gain that would make it worth the expense for a street use vehicle. With the turbo in the Subaru, which was over $2000 for the kit, we got somewhere around a 2 mile to the gallon gain. Im also honestly not sure if anyone makes a kit to rebuild the 3.7 in your Dakota so that you can run a supercharger or turbo either, sonce Chrysler didnt offer one on those trucks, but if there is a kit for that, a search online, or, even a needed parts list from Moses, would be the best place to start, if you do decide to go that route, although, knowing that some Chrysler parts are a bit more expensive than comparable Chevy or Ford parts, the total cost, including labor, may make it not worth the expense. A potential downside to adding any kind of power adder though, such as a supercharger, turbo, or even just a power chip, would be if the state the Dakota is registered in does yearly, or alternate year, emissions tests, because adding a turbo or supercharger might cause emissions issues. The only way to know for sure if it would, is to ask around and see if anyone has attempted this kind of swap, and see how they worked around it.

 

On a side note, there are at least a couple guys here who both have the mid-2000 model year Rams, although both of theirs is diesel, they may have more insight into the fullsize trucks, as i tend to lean towards the Dakota, because it suits my needs better than a fullsize. One, as you already know, is Moses, who runs this site, and the other is Megatron, whose black 3500 Ram is showcased in the garage area on here, and, im sure if you ask around on the site, there are others who would be helpful with any questions you have on the Ram trucks.

 

Ultimately, i would weigh the pros and cons of just fixing the torque converter issue, versus rebuilding the engine in the Dakota for a turbo, versus just buying a fullsize, and see which option makes the best sense for your budget, as well as what you are ultimately looking for.



#7 Moses Ludel

Moses Ludel

    Administrator

  • Administrators
  • 1,117 posts
  • LocationReno Area...Nevada
Garage View Garage

Posted 24 August 2014 - 06:47 PM

I did some basic research on aftermarket supercharger results with the 3.7L V-6.  The interest in boosting power in the Liberty did spur some turbocharger and supercharger experiments with this engine design.  The net result, apparently, was that boost on a stock engine and piston was more than the pistons would handle.  The story that circulates is that the 3.7L has piston rings positioned high on the piston, and if you turbocharge or supercharge this engine, the pistons will fail.  Several prominent supercharger experts were allegedly involved in these tests.  These anecdotal kinds of comments need confirmation and further research.

 

Dropping compression is a practical consideration when turbocharging or supercharging engines.  Simply put, the normal compression ratio is determined with a naturally aspirated induction system.  Since this air enters the engine strictly by manifold/cylinder vacuum, the compression ratio is dependent upon ambient air and atmospheric pressure.  As an example, a naturally aspirated engine that develops 10:1 compression at sea level may develop, let's say, only 8.5:1 compression at 8,000 feet elevation.  Though this may not be the actual compression difference, we could do the math around the atmospheric pressure changes and their effect on compression at various altitudes.   As a footnote, an engine that requires 89 or 91 octane fuel at sea level may operate without ping on 87 octane at 6,000 feet elevation.  This is due to the drop in effective compression at the higher altitude and "rarified" air.

 

Similarly, if we supercharge or turbocharge an engine, we "boost" the atmosphere, depending upon the waste gate settings and how much pressure or boost we choose to apply above the intake plenum.  We might, for example, boost the cylinder volume and air-fuel to the point that the compression reaches 12:1 or higher with a stock engine that originally had only 9.5:1 compression.  This added air-fuel volume, compressed into the cylinders, places extra "inertial loads" on the lower end of the engine (as Biggman100 notes from his Subaru experience).  You can, quite literally, blow the lower (short block) end of the engine apart.

 

Do some types of V-6s handle turbocharging?  Here is a maximum output 3.8L Buick V-6 built for an '87 Buick Grand National drag racing car.  Note the extensive modifications and output, yet the compression ratio is only 8.2:1—before the boost!  The Buick is an iron block monster with unparalleled stamina (apparently unlike the Chrysler 3.7L Liberty and Dakota engine).  Read this account.  I'm not sharing this to encourage a similar build for the Dakota 3.7L V-6 but rather to show the out-and-out performance potential of a classic iron block V-6 pushrod engine:  http://www.superchev...grand-national/.

 

As a footnote to the "boost" and altitude, there's an old trucker's legend about Loveland Pass in Colorado.  In the day, before the Eisenhower Tunnel, the altitude was so high at Loveland Pass that trucks could not climb the pass without superchargers.  The emergence of supercharging and turbocharging on diesel engines coincided with the growth of the trucking industry and need to compensate for altitude changes.  And that is a significant benefit with boost!  The best news is that boost can be controlled precisely, like any tuning measure, to keep performance at a peak without exceeding the limits of the engine's architecture and components.

 

So, if the online scuttlebutt is accurate, the 3.7L is apparently not a ready candidate for turbocharging or supercharging.  Some hinted that forged aftermarket pistons might bridge the weaknesses of the 3.7L design.  (The 4.7L V-8 got thrown into the mix in this discussion, again hints about high ring locations on the pistons.)  If we get serious about supercharging the 3.7L V-6, or even the 4.7L V-8, let's research the pistons, rings and other concerns.  For openers, does anyone have a 3.7L V-6 piston to photograph and share?

 

Meanwhile, the 5.7L Hemi V-8 and a Ram truck sound like your best bet.  Our youngest son has a 2013 Ram 1500 4WD Crew Cab (rare) with the 5.7L V-8 and automatic.  When he keeps his foot out of the throttle and allows the cylinders to "drop off", the engine delivers consistent 21-plus mpg on an interstate cruise.  The truck's also more than qualified for your kind of trailering chores, Flynaround.

 

 Attached File  Used 2004 Ram 1500 4WD Find (4).JPG   166.63KB   0 downloads Attached File  Used 2004 Ram 1500 4WD Find (2).JPG   138.15KB   0 downloads Attached File  Used 2004 Ram 1500 4WD Find (3).JPG   71.75KB   0 downloads Attached File  Used 2004 Ram 1500 4WD Find (1).JPG   131.06KB   0 downloads

 

Also, a neighbor just bought this '04 Ram 1500 4WD Hemi Sport with every factory option available and only 60K documented miles—for only $12,000 from a private party!  This truck is next to the trailer they plan to pull.  I lugged this trailer to 2012 King of the Hammers at Johnson Valley with my '05 Ram 3500 4WD Cummins diesel.  If they can do this with ease, it will say a lot.  That trailer is around 7,500 pounds wet and without cargo.

 

Perhaps you can find a similar used Hemi 5.7L truck in this condition.  Or maybe you'll bring your other truck to Oklahoma and use the Dakota for light-duty hauling and sporting about.

 

Moses



#8 biggman100

biggman100

    Advanced Member

  • Members
  • PipPipPip
  • 230 posts
  • LocationNew York
Garage View Garage

Posted 24 August 2014 - 10:08 PM

Moses, i know the Buick in the link is a drag car, but, for many years there was a local guy who had a twin turbo buick GNX, that had 1,000 Hp, and over 1100 LB-FT of torque, on an all stock v-6, but a combination like that is very rare. Manufacturers rarely build cars that can be upgraded to that extent without major modifications.

 

Now, on to the subject of super or turbocharging the 3.7l Chrysler engine. I did some research, and found that noone makes a piston that will hold up to that kind of power, and the stock pistons seem to have very little material between the dome, and the first ring. I attached a pic of one i found online, so you can see what it looks like.

Attached Files

  • Attached File  $_12.JPG   24.32KB   0 downloads


#9 Moses Ludel

Moses Ludel

    Administrator

  • Administrators
  • 1,117 posts
  • LocationReno Area...Nevada
Garage View Garage

Posted 25 August 2014 - 02:58 PM

Biggman100...Thanks for the research on the 3.7L piston source!  The photo tells me that the stock 3.7L piston is lacking skirts.  The rings, if you consider the overall spread from top ring to bottom ring, is not severely impaired by design.  What scares me is the short overall height of a piston without skirts.  The rings that high on the piston allow the piston to rock with the short/lacking skirts.  The short spacing between the top of the top ring and crown lends itself to shearing the piston head loose as the piston rocks, especially under the forces of supercharging boost.  Perhaps the rings could benefit from lower positioning, but if this is not possible, your suggestion about aftermarket pistons is worth pursuing.  A forged piston, even with the higher ring locations, might survive reasonable boost if the compression ratio is dropped to 8:1 or so like the Buick GN engines.  A bigger piston gain would be longer skirt length, maybe the aftermarket forged piston takes that into account.  The reason for the skirt issue could be the connecting rod angle, this engine is a close to "square" bore/stroke arrangement (93mm x 91mm) by design. 

 

I found a rundown on the 3.7L SOHC V-6:  http://en.wikipedia....owerTech_engine.  It is a "PowerTech" series derivative of the 4.7L V-8, both intended to replace the aging pushrod Magnum 'LA' engines.  The blocks are iron, heads are alloy, so this is not radically different than the Buick 3.8L/231 GN engines and the Buick 4.1L/252 V-6 (both representative of the even-firing engine design era).  The displacement of the 3.7L is only 226 cubic inches, not earthshattering for a build-up.  I'd get more excited about a 4.3L GM Vortec (Chevrolet Division) pushrod V-6 design for supercharging.  Each of these engines is a 90-degree with erratic balancing issues at various harmonics, and the use of a counter-rotating balance shaft is common on later designs.  The 4.3L GM Vortec introduced this change in the mid-'90s L35 engine, I had the opportunity to walk that engine assembly line at Detroit on behalf of OFF-ROAD Magazine.

 

The connection between Buick engines and Jeep is the odd-firing 225 Dauntless all-iron, pushrod V-6 in 1966-71 CJs and the Jeepster/Commando.  There is also the late Kaiser era use of the bulletproof Buick 350 V-8 in the J-trucks and Wagoneers.  I maintain a warm spot for Buick Power.  On my shelf is a wonderful book I acquired when writing the tech columns for OFF-ROAD, Popular Hot Rodding and Guide to Muscle Cars in the '80 and '90s:  Buick Power by GM Buick Division engineers.  The book dates to the introduction of "Stage II" performance developments and an extensive list of performance parts from GM.  At the book's introduction, they were producing 6,200 V-6 engines per day!  Any questions about odd- or even-firing Buick V-6s?  Just ask!

 

Moses



#10 Flynaround

Flynaround

    Member

  • Members
  • PipPip
  • 3 posts

Posted 26 August 2014 - 06:42 PM

Thanks again for all the insight. I will not install a blower or a hemi in the Dakota now. So my next option is the 4.7 V8 that they came with. I have found a transmission shop that will rebuild my 42 RLE with heavy duty parts and a shift kit for $2300. They said with these heavy duty internal parts it will outlast the rest of the truck. So now I ask, if I rebuild the 42 RLE trans and repower with a 4.7 V8 later, will the V8 bolt up to the 42 RLE? Or will I need the 45 RLE 5 speed that the 4.7 Dakota came with? Then, will I need the transfer case to go with the 45 RLE or will the 42 work? I know it seems like a lot of work for a Dakota but it fits in the garage with the boat at the lake house and a full size won't. Also, I figure a 2006 Dakota quad cab 4x4 in need of a transmission is only worth $3500. A half way decent full size truck with 70,000 miles would probably cost $12 to $15 K. Then it may need repairs sooner than later which raises my investment. If I rebuild my trans, I will never need repairs on it again. I can shop for a low mileage 4.7 V8 in the mean time. I don't want too nice of truck, such as my 09 Ram that is show room new left parked outside at the airport that will probably get hailed on and go through a tornado or two. Thanks again, Mike



#11 Moses Ludel

Moses Ludel

    Administrator

  • Administrators
  • 1,117 posts
  • LocationReno Area...Nevada
Garage View Garage

Posted 26 August 2014 - 06:59 PM

Mike...Basics like the bellhousing patterns should be the same, but I'm deferring to Biggman100 as to whether the transmission will work with the 4.7L V-8.  There's still the wiring changes, even with two factory engines for the Dakota.  PCM interface with the transmission may present differences, too.

 

As for the stamina of the 42RLE, it's been well tested in Jeep vehicles, including the Liberty and the Wrangler.  Seems reasonably strong, however, you're planning to pull a trailer in addition to sticking a 4.7L V-8 in front of it.  Again, curious if Biggman100 has experience with this. 

 

Here's an interesting insight from ATS.  They beef up the 42RLE for the Jeep applications.  There appears to be a laundry list of needed upgrades, which your local shop may be addressing also.  This is not confidence inspiring as far as the stock 42RLE goes, though after a rebuild on this level, these units should be quite strong.  You might compare ATS and your local shop's approach to see how each stacks up:

 

http://www.atsdiesel...sp?p=3069408320

 

Moses



#12 biggman100

biggman100

    Advanced Member

  • Members
  • PipPipPip
  • 230 posts
  • LocationNew York
Garage View Garage

Posted 28 August 2014 - 01:49 AM

Mike, the bell housing pattern is the same, as far as I know. I will do a bit more research on it and get back to you asap, but, from what I do gather, the 3.7 is basically a 4.7 with 2 less cylinders, which is why most of the externals are interchangeable. The weak link In that swap is the transmission, but, since you are upgrading it, it should hold up very well behind the 4.7. The downside to that swap will be the PCM. It may have to be reflashed to control shifting and other functions for the transmission, since the 3.7 and 4.7 have different transmissions behind them stock. Wiring should also be direct interchange, although you will need the entire engine bay harness from the truck the 4.7 comes from, as well as the 4.7's PCM. Being that the only swap I have done of this type was a slightly older year than yours, a 2003, I don't want to give any wrong information here, so I will verify everything through a couple friends who have done the swap on a 2007, and I will get back to you asap with the needed info.

#13 biggman100

biggman100

    Advanced Member

  • Members
  • PipPipPip
  • 230 posts
  • LocationNew York
Garage View Garage

Posted 28 August 2014 - 01:52 AM

One option though, that might make it all a plug and play swap, would be to find a complete, running, but wrecked 4.7 truck, and swap engine, trans, wiring, transfer case, and driveshafts to your truck, but then that would negate having your transmission rebuilt.



Also tagged with one or more of these keywords: Dodge 4WD truck

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users