V6 Transplant

[1941Rick]

Anyone use a Dakota 3.9 or 3.7 V6?

Run into ant difficulties?

My L6 is sick and am thinking of a V6.

[Plymouthy Adams]

got a 3.9 w/4 sp auto and a 3.7 w/sp stick....if you got tools, room and fab skills..they a piece of cake...

[Tim Keith]

The 3.6 Pentastar would be good too.  The 3.6 was on Wards 10 best engine list three years in a row.   But who has swapped one?  I think the 3.6 would be a good motor for a Dakota swap.  They are known to be smoother than many V6s and quite powerful.  

[Plymouthy Adams]

while the RWD 3.6 engine may be a good transplant I admit not to have entertained them simply because of the fact that I also do a frame clip along with the engine/tranny upgrade...the Dakota is an excellent platform for this application and is readily and easily joined to the existing older frame.  I have looked at a few of the later designs where a cradle is used..but the forward frame rails of the older car and the front bulge that IS the spring pockets...big big draw back..unless you make your own forward frame rails to retrofit...boxing these pockets is still a bit of a task

Edited June 5, 2014 by Plymouthy Adams

[1941Rick]

My biggest concern is the electronics.......Shop and fabbing no problem...

I would prefer to not put in a clip.....

[Tim Keith]

I looked up 3.6 swaps, if anyone has done it they haven't posted results.   But lots of people don't post on the internet.  I thought the 3.6 would be good in a 1st gen Dak,  on paper its got twice the horsepower of the older 3.9 and the economy is good too. As I don't see that the Pentastar are known for problems, the 3.6 from wrecks shouldn't be in much demand. A twin turbo model on the way .  The Pentastar ought to see more interest as time passes.   It also weighs almost 100 pounds less than the 3.7 Chrysler V6.  But the wiring is complex.

 

http://www.pentastars.com/

Edited June 5, 2014 by Tim Keith

[48Dodger]

My biggest concern is the electronics.......Shop and fabbing no problem...

I would prefer to not put in a clip.....

 

Old frame suspension with modern motor......seems there are always problems with that....brakes usually tops that list. Do you already have discs brakes? 

 

48D

[1941Rick]

Disc brakes in this winter......

Suspension is up to the job......

[Plymouthy Adams]

1941Rick, on 05 Jun 2014 - 01:00 AM, said:1941Rick, on 05 Jun 2014 - 01:00 AM, said:

My biggest concern is the electronics.......Shop and fabbing no problem...

I would prefer to not put in a clip.....

Electronics is not an issue if you get the wiring harness along with the donor drivetrain....my cars all have the  donor harness ....it is just too easy....and it does not just stop at engine controls either..get the whole nine yards...go ape wild...put in the Air Bag, stereo, AC and ABS brakes, body controller....cruise control...zero emission fuel system, electric windows etc etc etc...heck even use the modern cluster retrofitted...why sell yourself short...

Edited June 5, 2014 by Plymouthy Adams

[1941Rick]

If I go this way I will not put in "all" the creature comforts......want to keep the stock look but when the hood goes up the Wow Factor takes over.

I get that with the flatty right now. You see lots of V8's but very few V6's. Have found the parts to build a Hyper Slant Six, but they are too long. Not going to chop a firewall.......

[Plymouthy Adams]

IF you go this way the creature confrots are the least of the problems..actually they are the things that are NOT as we say,  complicated..hard to make an omelet without breaking a few eggs

[Tim Keith]

You can install a slant six by relocating the radator support. I wouldn't cut the firewall, but its not so easy to make it look right. 

 

I like the 3.6 "Pentastar" as its a 60-degree V6 that is narrow, should clear the steering better.   The newest 3.6 has 305 horsepower, not that I'd need that much power.   There just isn't much knowledge on how to swap the 3.6 and aftermarket support is low.  The integral exhaust manifolds help make the 3.6 more narrow than it might be.  On paper its a fine motor, but Mopar people will always focus on the V8, and I don't see that's a bad thing.  Next year the 3.6 gets direct injection, usually this kind of power output comes with DI, so there could be more power in years to come. 

[Plymouthy Adams]

_{slant six is doable as is the flattie for rebuilt and popping up a bit..but the big question...limited as it is and the cost involved and the price of any reasonable facsimile of spped parts from the olden days of the hyper six....WHY}

[1941Rick]

Exactly...that is why I am thinking V6......For all those extras you mentioned I might as well just drive my every day car......Optima.....

[Tim Keith]

Exactly...that is why I am thinking V6......For all those extras you mentioned I might as well just drive my every day car......Optima.....

 

Its not difficult to build a fun slant six without a lot of "speed" parts, much as you can do the same with a flathead.  You can get camshafts and intake manifolds.  The big improvement comes from raising compression, valve and head work.  The 225 used the same head as the 170, head work can help quite a bit.  Many stock slant sixes are near 7:1 static compression. Raising the CR to 9 helps a lot.    The hyper-pak looks cool but the Clifford four barrel is probably better.  The Mopar Performance two barrel was good but is NLA.  The Hyper-Pak being reproduced today might have quality issues.  There are some good manifolds from Aussie Speed as well, but I think those are spendy.   A slant six with 150 to 180 horsepower is spunky, smooth and easy to live with as its not highly modified.  Building more than 220 HP requires more work, but a turbo charger helps there.   I have Dutra Duals and an Offie 2 x 1 manifold but I'd like to fabricate an equal length runner EFI manifold as these inline sixes have fuel distribution problems.  There is an effort to bring that type of manifold to production, but I'm not holding my breath on that.   You might follow the August Mopar Muscle article on building the slant six.  In that article they milled the block and the head deck .060-inch each to raise the compression.  

[james49ply]

my question would be what would you use for fuel delivery, carb, aftermarket fuel injection or the original wiring and computer for the 3.6?

[Tim Keith]

my question would be what would you use for fuel delivery, carb, aftermarket fuel injection or the original wiring and computer for the 3.6?

 

I don't know of anyone who has seriously looked at a 3.6 swap.  I think it would have to use the original engine controls as you'd have to fabricate an intake manifold for a carb. Plus the static compression is like 10.5:1, without the ECU you would need premium fuel.  Sitting down with a wiring diagram and determing which wires could be terminated and which were essential would take some effort.  The 3.6 is common to many vehicles but each would have its own programming.  If there were a Painless engine-only wring kit that would work for the older vehicles, but I don't see that happening.  V8s rule with Mopars, swap out the 3.6 for a Hemi is the way it goes.  The 3.6 gets good new car reviews but I don't see an aftermarket.  That's not the say that someone here couldn't get a wrecked vehicle and transfer the motor, transmission and wiring over pretty much as is.

 

I just did an internet search and found there is aftermarket equipment for the 3.6, but didn't see anything to help with wiring.

Edited June 6, 2014 by Tim Keith

[Plymouthy Adams]

my question would be what would you use for fuel delivery, carb, aftermarket fuel injection or the original wiring and computer for the 3.6?

the very design and profile of the cam etc is set around the SMPFI system..you will not see the same results less electronics and through natural aspiration..

 

use the factory wiring...take full advantage of the performance and reliability design into it by the engineers..and if you think quiet smooth dependable roll on power of a modern EFI V6 is too "new car" and you may as well drive an Optima....then yeah build a high cost iron lung that will eat your wallet and take build funding from other areas of the car and cost you out the yang in fuel to propel down the road..the above high dollar speed built slant six is still way under in HP than my 3.7 that IS NOT touted as a performance engine...

 

as for the ECU and wiring...get the book..look at the inputs and the power requirements..runs on 12 volts same as any other part you putting on your car..if everything was plug and play with the builder not hving to be pro-active in any manner...then it would not be referred to as building my car..it would be called 'bolting my car"  well we have that with the glass deuce coupe and other kit stuff today...m ay as well market a paint by number color kit for the body

[chopt50wgn]

The one thing I haven't heard is the fuel system changes. For most all the fuel injected systems you need to re-do the plumbing as well. Having an electric pump for proper pressure and in some cases, a return line to the tank.

I know it's not rocket science to change over, but is something that needs to be though out.

[greg g]

Are't these the engine that have the exhaust manifold cast integral with the cylinder hear, and don;t they have the cats mounted right there to the "head"?  What is are the engine dimensions including the cats???  I guess you could fabricate plumbing to  mount the cats elsewhere but then you would need to deal withthe O2 sensors wiring.

 

 

[Plymouthy Adams]

I believe Ma Mopar did away with the fuel return on the 1994, the return is needed IF your fuel regulator is on the manifold or fuel rail etc,...the regulator is now in the same  all in one assembly, pump, filter regulator roll over and sender/low fuel...BUT if your regulator is on the mainifold/throttle body/fuel rail..then yes a return is needed..

 

another valid reason I so stress getting the ENTIRE donor body as in my case I used the zero emissions fuel system complete..simple and easy transfer tot he old body...get a performance minded V6 with great economy..may as well go for the 22 gallon gas tank while you got it available..

[1941Rick]

I was thinking more like an older 3.9 or even a 3.7.

3.6 is far to new.

[Tim Keith]

....then yeah build a high cost iron lung that will eat your wallet and take build funding from other areas of the car and cost you out the yang in fuel to propel down the road..the above high dollar speed built slant six is still way under in HP than my 3.7 that IS NOT touted as a performance engine...

 

 

 

If you want a normally aspirated slant six that makes 300 horse power, you'll have to spend the money for skilled cylinder head porting, although some do it themselves with a die grinder.   You can't just bolt on "speed" parts.  The head is where the power comes from in a slant six. Not much other "speed" parts are needed other than head work, camshaft and a compression increase with improved exhaust.   The slant six is relatively light in the low 400 pound weight, it weighs little more than the 3.6 V6. These new motors have rugged bottom ends.  The best power ever achieved in a slant six is around 700 horsepower.  These motors are fun and economical at 200 HP.   You can build a 14-second A body daily driver with a slant six without a big budget, but you should ask someone for advice or you could spend a lot of money for mismatched results.   If the slant six block were heavier in the bottom the power might go higher with turbo charging but the light block tends to break because of the torsional whip of the long stroke.   In my opinion the potential for an economical and quick daily driver slant sixes is with turbocharging as the heads need not be modified much.  Every low buck turbo build seems to be different, using parts from Ebay or Pick N Pull, maybe not so well planned.  In the future I think turbos is where the slant six fun is.

 

The block dimesions of the 225 are similar to the classic Jaguar six, but with a simpler head that does not breathe well stock.  Jaguar made its block heavier to tolerate more power and that inline six is a boat anchor because of the weight.  When the slant six was developed in 1957 the Jag six had the highest specific output of any production motor in the world.   The bore spacing (about 4-inch) and bore and stroke of a 225 is similar to the Jaguar 3.8 liter.  I think that its reasonable to think that the slant six  was influenced by the Jag six.

 

Lou Madsen who posts on slantsix.org has a knack for building daily driver slant sixes that are quick and economical.  There are several others who can offer good advice on slant sixes.   The late model engine swaps have good power, but being able to understand the total build helps in long term maintenance.  Someone can understand what is in a slant six decades from now.  I drove my '64 Valiant for 120 miles a day for two years, it got 24 MPG.  I never had any trouble keeping up with freeway traffic. This was 3 years ago.  The odometer was broken, I have no idea how many miles were on the motor.  I'm a fan of the slant six.

[Plymouthy Adams]

I am a fan of the /6 also..just not for retrofitting and street running.....for the eco box and dependability..hands down...excellent and I have owned and driven a goodly number of them...if you bracket racing and fitting a niche in the program..they have their place..

[Tim Keith]

I would think a wrecked rear drive vehicle with a 3.6 wouldn't be too expensive as few people would have need of the used drivetrain. That's true with the drivetrain of wrecked late model cars like Caddilac,  the motors don't fail - other than from extreme abuse - driving with no oil etc. There is little demand at the salvage yard.   I think some early issues with the 3.6 are now resolved.    The engineers were able to reduce the number of the major parts in the 3.6 significantly to cut the costs to make most of the engine assembly the same for different vehicles.   There is an aftermarket for the 3.6 but thus far I don't see anybody swapping one .    My 3.6 swap platform of choice might be a first gen Dakota as the 3.6 would double the power over the early 3.9 V6.   The exhaust of the 3.6 GM motor used in the Camaro sounds rattly to me, I think the Mopar 3.6 is a smoother and more refined motor.  Next year the 3.6 will get direct injection, and more power.   I could do without the DI if I had the torque, the 300 HP and the fuel economy.  The narrow 60 degree V6 should fit better in many older cars with steering box issues, the integral exhaust manifolds allows for a more compact motor.