A few additional things for the Chrysler FWD crowd to chew on... Ver 2.5.2
I'm pulling info from many sources. Dr. David Zatz and his ALLPAR site, my friend Rob Carter's 3.0 FAQ and his General FAQ, Gary Donovan's site, Paul Berkebile's site, James Dempsey and his Chrysler 3 liter mailing list, Rob Carter and I collaborated on the NEW Mopar minivan Homeworld, and my own personal research. And many other sources and people and such. Too numerous to mention. Including several Chrysler service techs who shall remain nameless for their own protection...
CHRYSLER 3.0 LITER V6 AS MANUFACTURED BY MITSUBISHI MOTOR COMPANY
I've done a fair bit of research into the variants of this motor. This motor appeared for the Chrysler minivans in mid 1987. Was included with the introduction of the stretched minivans that became the Grands. This motor was built by Mitsubishi motors, and was altered to Chrysler's specs. Our version is a Multipoint Fuel injection motor, and was later upgraded to Sequential Multiport. It uses a "Speed/Density" computerized system to regulate fuel, which has a Manifold Absolute Pressure sensor to allow the computer to "gauge" how much fuel to add. Not too bad of a system, but not real performance friendly. And the fuel mappings in the computer are geared toward staying environment friendly, as opposed to performance friendly. Check the links for power ratings by year and model...
The timeline for MAJOR changes is:
The Mitsubishi version of this motor was used in cars and trucks, including the 3000GT flagship. This motor was available in their Montero and trucks as SOHC, and also in their Diamante sedan from about 91-94 and the base level of their 3000GT for most years of production, again as a SOHC. The 3000GT also was available with the basic block and lower end, but with DOHC and with or without Twin Turbos. As such, this basic motor could be had in flavors from 150 hp to better than 320 hp. The Diamante and Montero later received the DOHC versions and were later upped to3.5 liters. But the twin turbo motors were never offered, though, there are unconfirmed reports in the Montero community that Jackie Chan (yes, the martial arts actor) had a Pajero custom ordered with the TT motor… All versions in the Mitsubishi lineup used Mass Air Flow computer systems.
For the remaining purposes of this discussion, I'll be referring to the SOHC
version unless I specifically mention the DOHC or Twin Turbo (TT) models.
Nick Boers had
started to use the plenum and intake from the Hyundai Sonata version of this
motor for HIS turbo project, but finally fell upon a reworked stock one like the
rest of us are using. To mention intakes and plenums... For the Chrysler motors,
there are two different lower intakes and two different upper plenums. '87
& '88 and '89 and newer. Two major differences are mounting tabs for
the Fuel Pressure Regulator present on the older style, but not the newer, and
for the PVC valve relocated to the newer intake. In '87-'88 the PVC valve
mounted in the valve cover. This also means 2 different front valve covers
too. Then there is the Sonata version. Then, there are two different plenums and
manifolds for the Mitsubishi vehicles. One each for the truck/SUV and one for
the sedans and base 3000GT. There are also differences in the oil pumps and
filter locations, Chrysler has a pump specific for its use, with the filter
located on the "front" (as viewed with the hood open) of the block,
while the Mitsubishi cars use a pump with the filter located on the pump and
various adapters are used to alter the filters position depending on application
and whether there is are turbochargers used or oil coolers. Could such a pump be
used on the Chrysler FWD applications? No, the right side halfshaft is in the
way, explaining the difference.
Exhaust manifolds. The Chrysler motors have at least three variations, the 87-88 manifold has a 2.25" outlet, and in 89 this was increased to 2.5" which was a running change across the Chrysler line. The 87-88 motors may have all had an EGR port (all evidence so far points to this…), but in 89, seems only the California vehicles got EGR ports, so some manifolds have this port, others do not.
I also know of 3 diffent styles of exaust manifolds. I have 3 diffrent styles in my posession. One 2.25" and 2 2.5". Were there more. I'm not sure.
There were also 2 diffrent fuel rails. The older rails supposedly flow better than the newer style. Circa '92?
Now for even more confusion. There is evidence that this motor has also been used in Mitsubishi made forklifts and other machinery. Obviously, those versions are seriously different, as they usually run on LPG or Propane fuels. Since this basic motor is used in such applications, that tells me that it is a strong and reliable motor. And I’ve even seen a DUNE BUGGY (8 seats even, can you say "Minivan of the Dunes"?) with the industrial 3.0...
This motor is very capable of handling a lot more power than it has stock. It uses the same basic block, crankshaft (though in later years the TT version was Nitrile treated), and bearings and rods. The main difference was that the block was machined to accept a 4 bolt main bearing cap, instead of the two bolt mains, and the pistons are different for the SOHC/DOHC FWD, TT and RWD SOHC motor. THe Chrysler motor seems to have yet another piston. Clearances are basically the same though regardless of pistons or application. The DOHC heads will bolt on the SOHC block. So this is a way to generate more power, but then you need the whole computer and wiring harness from the donor car. Same thing if you decided to get the TT DOHC setup as well. Or for that matter, the whole motor.
It also appears that the trucks got a different cam profile than the sedans
did. Also, the Chrysler version has distinctly different cam timing from the
Mitsu applications. Since all the SOHC models used a distributor based ignition
system, it would seem that the hot cam to get for us (minivans) would certainly
be the one from the Mitsu Montero/trucks. I ask out loud for the first time, but
for the untold countless times in my head, why didn't Chrysler offer some of
this stuff? And why is there such a vast difference between the Mitsu
application motors and ours? Is this due to the different computer applications?
Check out the little chart I gathered here:
Mitsu 3 liter V6 specs
Mitsu vehicles (From these online resources, Mitsubishi 6G72 FSM, Montero FSM, and Haynes Montero/truck manual) (the Montero site appears to be down at this time. I managed to download ALL their FSM info, but am not sure how best to make it available since I am concerned with copyright issues...)
SOHC Specs
FWD
Compression ratio
10.0
valve timing
intake open
16 BTDC
close
66 ABDC
exhaust open
56 BBDC
close
26 ATDC
injector N210H
RWD
Compression ratio
8.9
valve timing
intake open
19 BTDC
close
59 ABDC
exhaust open
59 BBDC
close
19 ATDC
injector B210H
SOHC Piston Clearance
Piston to cylinder
.02-.04mm (.0008-.0016")
Service Size (Overbore) .25,.5,.75,1.00mm
.010,.020,.030,.039"
DOHC Specs
Non-Turbo
Compression ratio
10.0
valve timing
intake open
16 BTDC
close
55 ATDC
exhaust open
48 BBDC
close
15 ATDC
injector BDH210
Turbo
Compression ratio
8.0
valve timing
intake open
16 BTDC
close
55 ATDC
exhaust open
50 BBDC
close
17 ATDC
injector BDL360
DOHC Piston Clearance
Piston to cylinder
.02-.04mm (.0008-.0016")
Service Size (Overbore)
.25,.5,.75,1.00mm
.010,.020,.030,.039"
All Mitsu versions appear to use a 60mm throttle body.
Chrysler version (According to my '87 FSM and Rob Carter’s 88 and 89 FSM)
Compression ratio
8.85:1
valve timing
intake open
19 BTDC
close
57 ABDC
exhaust open
57 BBDC
close
19 ATDC
injector No Info
Piston to cylinder
.02-.04mm (.0008-.0016")
Service Size (Overbore)
.25,.5,.75,1.00mm
.010,.020,.030,.039"
Chrysler version (According to my '92 FSM) Apparently the differences is due to a switch from MultiPoint Fuel Injection with SMEC (Single Module Electronics) to Sequential MultiPort Fuel Injection and the SBEC (Single Board Electronics)
Compression ratio
8.85:1
valve timing
intake open
19 BTDC
close
59 ABDC
exhaust open
59 BBDC
close
19 ATDC
injector
No Info
Torque
170 Lb. Ft. @ 2800 RPM
Piston to cylinder .03-.05mm (.0012-.002")
A BIG question that runs rampant through the mailing lists, and seems to be full of disinformation, whether these motors are interference or not. By interference, I mean if the timing belt breaks, will the pistons and valves hit. I'll let Robert Carter answer this one…
Read on: Straight from '88 Van FSM Page 9-51 "Pistons: Are aluminum alloy with a steel strut, short height, and thin wall so as to be autothermic and light weight. The piston head with valve recesses, in combination with the cylinder head, forms a compact spherical head WITH CLEARANCE FOR TOTAL VALVE LIFT WITH PISTONS AT TOP DEAD CENTER." I think this answer's the long debate on whether or not the 3.0 is an interference engine.
And for the record, my 87 and 92 FSMs (Factory Service Manuals) back this up too.
Drew Beck has an excellent chart on applications for the minivans.
TRANSMISSIONS AND SWAPS
The A670 and A604 automatics share a common right side extension housing. This housing includes the bearing and seal for the right side of the differential. What is the significance here? Um, well, the A604 was the only transaxle offered for the AWD minivans. If you were to unbolt the extension housing from the the 3 speed automatic (A670), you could then bolt in the adapter for the AWD Power Transfer Unit. Then, bolt in the PTU and there you have it, power transmitted to the rear of your A670 equipped vehicle. But wait, if it fits the A670, what about the A413? I'm looking into that, anyone interested in finding the power limits of the AWD drivetrain with a turbocharged 2.2/2.5 four banger? Wouldn't an AWD launch be fun?
"The extension housing is the same between the A413 & A670 transmissions. It is also the same on the 5 speeds."
Thanks Rob, we DO need more info on this. I’ve been in touch with a Chrysler Transmission service tech. He tells me that the 5 speed extension is different. True, the manual and automatic vehicles use the same halfshafts, but the differential bearings and differentials themselves are probably considerably different. I’d like an answer to this too.
I was originally told that the 3.0 shared bolt patterns with the 3.3/3.8. I know of a gent that was trying to mate the A543 5 speed to a 3.3. Didn’t fit... Back to the drawing boards. Although, I’d still like to know more about the 3.3/3.8 and the 3.5 sharing a common pattern. Anyone help me out here?
A handful of folks on the 3 liter list have already replaced their A604 automatics for the A543 5 speed. The latest to plan for this is the gent with the factory prototype turbo 3.0 V6 he installed in his P body. And I know of at least one minivan owner gathering parts for this swap too. Seriously, ALL the parts are available, so why not. And since I do a bit of driving in the mountains, I'd like an extra gear or two to choose from too. More on this as I think...
Computer and Fuel Issues
I'm learning what I can of the computer. So far I've learned that the computer isn't going to be an easy hack. Working that issue. We do know, thanks to Rob Carter, that the 88 Dynasty computer WILL run the 88 van. Might be good for someone to know… The computer for the 3.0 remained pretty much the same from 87 until 91. In 92, the newer SMPI system went into service.
Fuel. Fuel pressure in 87 was only 26 PSI, raised in 88 to 48 PSI, supposedly to prevent fuel boiling in the fuel rails. It remained at 48 PSI until the last year of production, 2000…
PERFORMANCE ISSUES
For those looking to increase power from their 3.0s... Hot tips here. Also, see Robert DeLucas’ EXCELLENT site...
-52mm throttle body. Look for those from the 87/88 3.0 vans, 3.3 and 3.8 vans. Also, the later model 3.8s seem to have 58mm throttle body, but this requires porting of the intake manifold where the throttle body mounts.
-89 and newer Intake manifolds and plenums seem to flow more air. Especially with a mild to wild porting by Nitetrain!!!
-Nitetrain also offers PHENOLIC spacers to replace the gaskets between the intake manifold and the plenum.
-Pre-SMPI fuel rails seem to be able to flow more fuel than the later model fuel rails. (Thanks Nick)
-The fuel pumps we use are the same fuel pumps used by the Chrysler turbo cars. Unless you are making OVER 300 horses, your fuel pump SHOULD handle it just fine. Make sure you change your fuel filter regualarly...
-While on the topic of fuel, I’ll raise the debate on fuel injectors. Our stock injectors are 19 pound per hour (lb/hr) units. These will only support 185-190 HP. I’m planning a swithc to 27 lb/hr units from the 2.2 liter turbo 1 cars. Depending on which method you use for determining how much HP these will support, they will support 235-250. The debate isn’t whether they will work or not, but whether there will excessive fuel consumption during start up and warmup phases when the computer is in OPEN LOOP mode. I’m going to find this out soon enough.
-Porting and polishing the heads. This is something I’m doing now. I have a spare set I’m working on. Others (Rick Lozier and Ron Adair) have done this with GREAT success. I’m just doing a little port matching and cleanup. Nothing radical.
-Camshafts. There isn’t an aftermarket cam available to us other than the ones from RPW in Australia. Available here in the States thanks to Phantom Racing. I’ll cover Phantom more indepth later... Though, Crower cams in Chula Vista. CA will regrind our stock cams to any spec within reason. Be careful of increased lift though, since we would hate to turn our non-interference motors into interference... Also, SOHC 3.0 Montero cams have better duration and would appear to have better torque.
-Speaking of torque... I’d like to find out more about the SOHC 3.0 Montero intake manifold and plenum It looks sort of like the last 5.0 Mustang plenum, but I’d almost bet that the Montero setup makes more torque than our stock units... Waiting to see...
-Exhaust. Well, not much available in the aftermarket for our motors. If someone made a header set for this motor, it could be used in ALL Chrysler 3.0 platforms. No changes needed... I was thinking the earlier SOHC Mitsu Diamante manifolds were going to be the ticket, but perhaps not. Clearance issues. Same too, with the Montero manifolds. Rick Lozier had a custom set of headers made. Nitetrain is currently working on some too. Developing...
-Nitrous. Well, I’m not a fan of Nitrous for many reasons. Check this site out. KABOOM!!! Also, when the bottle is empty, your slow again. On the other hand, Rick Lozier had a good deal of success with it, dropping his Daytona 3.0 into the twleves on the squeeze... Just not for me.
-Supercharger. Seems to be a couple companies out there that have or will develop a kit for us. Sorry, when the price gets over $1000, I stop listening. But don’t let that deter you if that is the way you choose. Also, Nitetrain is working on a blower for his 3.0 Daytona. The plan is to get it under the STOCK hood. Of course, check out the worlds first supercharged 3.0 liter NEON!!!
-Turbocharging. Robert Hassler has a FACTORY turbo motor. He bought two of the engineering prototypes and installed one in his car. Not all of us can drop that kind of change, but glad he could rescue these motors. But this doesn’t mean we are through with this discussion... No, not by a long shot... The biggest problem, is geting an exhaust manifold or header available to ease the process. I can’t weld cast iron, or i’d have been done long ago. Everyone seems to be concerned with routing exhaust back to the stock location, and I am beginning to think this is a Nirvana that won’t be reached... So, I’m about to abandon ALL of my previous planning and fitment for something new... Stay tuned...
CREDITS, THANKS AND NEEDS
I’d like to thank Robert Carter III, Robert Hassler, Adam Baubach, Paul Berkibile, Drew Beck, Jay Storm, James Dempsey, Ron Adair, Rick Lozier, Gary Donovan and others IN NO PARTICULAR ORDER! Without the 3.0 list, and the subscribers to it, this information wouldn’t be available in 1 location. Shoot, without those that have access to Factory Service Manuals, lots of this wouldn’t be here. Also, I’d like to thank the folks at Ventura County Montero club for the FSMs and Haynes manuals on line for the Montero AND Conquest (2.6 turbo), and the folks at Club DSM for the 1993 3000GT motor FSM. All these references have been extremely valuable, and could lead to other developement for us as well. Certainly helps us with alternate parts (higher compression pistons and cams with different timing values).
As I get more information, I’d like to add the factory turbo info as a block. Also, I’d like ANY motor/manifold/plenum information of the Hyundai Sonata, the industrial (forklift) version, and anything anyone might have that could be of help for others. Even international versions of the motor including Export versions of our own Chrysler 3.0 liter V6. Thanks for reading.
Keep in mind, I am NOT an expert. This is the research I have done on my own, and now increasinly, with the help of others. I know for a fact it is incomplete because I don't have access to some information others may have. I do know that this IS the beginning of a FAQ for the 3 liter mailing list. If anyone wants to add anything or use anything, please, let me know, and give proper credit if it comes from a book. Getting more power from the 3 liter motor is a common goal for many of us. We have many bright people coming on board to help us out. This is a work in progress...
Also, for the short term, until this is more complete, I’ll be showing other’s inputs in red and my additional and new comments in lite green...
Email me at phatfoto@yahoo.com
Version 2.5.2 removed erroneous transaxle info. Added relavent manifold info. Added computer, and fuel info. Dated Apr.29, 2001