Cummins R2.8 Engine Swap

The time has finally come for the big project: A Cummins R2.8 Crate Engine Swap!

Instead of sinking time and money into the original 30 year old 4D56 and destroying any semblance of reliability, we decided to start fresh and shoot for the moon with this R2.8 engine from Cummins. The primary driver for this upgrade was speed & power to overcome the ten mile mountain climbs of the Rockies and to have a brand spanking new driveline.

For reference, this project began in January 2022. It took about 7 months to get the van back on the road and driving with just myself doing the work. This includes the 1 month lead time for the transmission build. I’d estimate a few hundred hours over the course of the 7 months. Then another few months of testing and incremental tweaks to get all the sub-systems working and dialed in. For an “official” build completion date of December 2022. All in, I’d estimate the whole project cost to be around $18k for parts on the van. This includes replacing a lot of old OEM hardware along the way and other supporting upgrades.

Why the R2.8? It is a combination of factors. The R2.8 has about double the horsepower and torque of the original 4D56. It is also about the same size. Based on my measurements the new engine is only 1″ larger in X, Y and Z, so a good fit when space and drive-line size is limited. Based on shipping weights, the R2.8 is only about 50lbs heavier than the 4D56/D4BF. In contrast the older Cummins 4BT weighs almost 500lbs more than the 4D56/D4BF. The R2.8 is also the only diesel crate motor available in the US, and comes with a complete plug and play turn key style kit, including ECU and all the fixings. The 16 valve 4 cylinder engine has a sleeved cast iron block, cast iron head and common rail fuel injection resulting in power, serviceability and reliability

To handle all this power the original A44D automatic transmission is being replaced with a custom built GM 700R4 transmission. The highest power A44D application seems to be the 1st and 2nd gen Montero, so no where near the 320ft-lbs that the R2.8 puts out. Our 700R4 is built by Novak to handle 375ft-lbs of torque (Basically V8 Corvette spec). It’s tuned to provide noticeable and satisfying shifts like the original. The 700R4 is also shifted by a cable, like the original A44D, which provides easy integration and tune-ability. Similar length, final gear ratios, reliability and US availability pushed this transmission to the top of the list.

This 700R4 is mated to a Jeep 231 Transfer-case through a slim Novak adapter. This is one of , if not the shortest transfer case adapter on the market at about 1″ thick. The 231 was chosen for its functionality and size. The 231 is one of the shortest readily available transfer cases on the market. It is a 2 speed case that has a left hand drop to match what the Delica is setup for. 4 low is 2.72:1 so an improvement over the original 4 low of 2:1, and yes the brakes can still hold her back in 4Lo. The final output is through a Extreme Short Slip Yoke eliminator made by Teraflex to eliminate even more driveline length. This slip yoke eliminator results in a transfer case that is 1.5″ shorter than an Atlas II.

Below is the original A44D next to the new 700R4. You can see that the 700R4 is much beefier. The stock drive-line measures about 39.5″in length and the new drive-line 38″, so we did manage to squeeze out an extra 1.5″ from the new drive-line. This will help with drive shaft geometry later on.

The combination of engine, transmission, transfer-case and slip yoke eliminator results in a drive-line that is +/- 2″ from the stock 4D56 and A44D automatic combination, all without sending vehicle weight to the moon. Overall size is critical, since the stock driveshaft is only about 16″.

Parts List By Sub-System

ENGINE:

• Cummins R2.8 Crate Engine Package
• Quickdraw Brand GM Trans Adapter
• Quickdraw Brand GM Reinforced Flexplate
• Rear Main Seal: Cummins 3693669
• Block Heater: Cummins 5320949
• Block Heater Cable: 251919
• Serpentine Belt: Cummins 5254354 Longer to accommodate AC Compressor
• Belt Tensioner: Cummins 5262500 For Longer belt
• Axis Industries Universal Motor Mounts-Modified
• Axis Industries Oil Pressure Adapter

TRANSMISSION:

• Level II Built 700R4 Transmission
• Novak 231 Transfer Case Adapter
• Jeep 231 Transfer Case
• Teraflex Extreme Short Slip Yoke Eliminator
• 1800RPM Stall Torque Converter (we tried the recommended 2500 stall and did not like it)
• Southwest Speed GM Tubular Transmission Mount (Chevy Nomad) – modified
• Shift Lever, 74124 – modified
• Novak SK2X Transfer Case Shift Kit
• GM Steel Torque Converter cover

Everything Else:

• Vibrant 12833 Intercooler Core
• 1970s Dodge Ram Charger/Challenger/Mopar Radiator
• Dakota Digital Mechanical Speedometer Adapter (ECT 200BT)

Engine Prep:

1. The first step was going through the engine and ensuring some of the critical components were torqued correctly. The rod and crankshaft bolts were all torque checked.

2. Next the Axis Industries oil pressure adapter was installed. This allows for the original Delica pressure oil switch (black) to be installed, retaining the functionality of the oil light on the dash. I have also installed an OE Mitsubishi oil pressure sender (silver) for my dash gauge on the same line. I would say having an oil pressure gauge of some sort is a must, since the oil pressure switch on the R2.8 only activates at 4PSI (the stock 4D56 switch is around 10PSI).

3. Next the Quick Draw GM Transmission adapter was installed. First a new rear main seal was installed into the adapter. This adapter actually replaces the entire timing chain cover, so installation was a little involved, but the adapter does not add to the overall engine/drive-line length, so a huge plus! This was another contributor to the 700R4 transmission selection.

4. Quick Draw also makes a low profile aluminum upper timing chain cover, further reducing the engine length. Unfortunately the supplied hardware was too long, so all of the cover bolts had to be ground down.

4. Next a 1/4″ NPT hole was tapped where the exhaust headers merge. This location provides the most accurate temperature measurement. This will be for our VDO EGT gauge sensor. The turbo was removed to prevent metal shavings from falling in.

5. A block heater and cable was added to the back of the water pump using OE Cummins parts.

Driveline Characterization :

1. To keep the original Delica shifters for both the transmission and transfer case, custom linkages must be designed to work with the existing cable throws. We characterized the shift pattern. Fortunately, the A44D and 700R4 have near identical shift patterns. The only difference is that the 700R4 shift linkage is inverted, but the actual positions are the same. A custom flipped linkage should be an easy solution. The 700R4 pushes the transmission out of park, while the A44D pulls, but the inverted lever, makes it the same. The 700R4 has an extra overdrive position, allowing you to select through all 3 gears. An extra position will be made on the OE shifter. OD should only be used for highway speeds (50mph+). Cruising around town should be done in D(3). The linkages are also both on the LH side, which is extremely convenient. See below:

2. A custom linkage for the Jeep NP231 will also be made to work with the stock Delica 4WD shifter (only one of the two cables is needed). The cable pushes the stock linkage from 2HI to 4LO. Similar to the transmission linkage, the shift pattern is the same on the NP231, but the linkage is inverted. The NP231 also has a neutral position between 4HI and 4 LO, this is great for dolly/flat towing.

3. The stock transmission cooling system will be reused as well, with the exception of the radiator heat exchanger. This was omitted to avoid any chance of cross fluid contamination. The 700R4 follows the exact same routing scheme as the stock A44D transmission. Transmission fluid goes first through the radiator heat exchanger, then the driver’s side trans-cooler and back. We may up-size the cooler or add an additional in-line cooler if it needed. The cooling lines are also conveniently located on the RH side, just like the A44D.

Transmission Prep:

1. The 700R4 is a lockup capable overdrive transmission. Lockup can be engaged in gears 2,3 and 4. 4th gear will be run with the torque converter always locked. This reduces heat and ensures that 4th gear stays lubricated. The lockup solenoid will be wired to a constant +12V source, with a brake switch and stock OD switch in series. This will do two things. The brake switch will disengage lockup when the brakes are pressed. This stops the drive-line from fighting the brakes. The second is that we will have the ability to disengage lockup in 4th gear (OD) if we want to (unlikely, but the hardware is there). So 4th gear will always have the toque converter in lockup under normal cruising conditions. This increases fuel economy and reduces heat.

We will also have a momentary switch wired into the ground. Making this ground connection will enable manual override and lockup the torque converter in gears 2 and 3. This will essentially enable engine braking like a manual transmission through the lower gears. Hit the switch and the torque converter will lockup in every gear except 1st (it is hydraulically impossible to lock up the torque converter in 1st). The brake switch will also still be functional and unlock the torque converter when the brakes are pressed in the lower gears.

The NC brake switch was mounted to a tab welded next to the OE brake switch. An extra tab to engage the switch was also welded to the pedal arm.

A momentary switch was added to the stock shifter head to manually engage lock-up in 2nd and 3rd:

2. Adding a trans temp gauge sending Unit to the cooler outlet using a 1/4″ NPT to 6AN fitting with 1/8″ NPT take-off. We will be adding new trans lines with AN fittings later on.

3. To use the original shifter, a mounting bracket was fabricated to hold the original cable and replicate the stock throw. The 700R4 has an extra position for the 3rd gear. This was easy to accommodate by tuning the shift lever on the transmission shaft. The original A44D shift lever was cut and welded to the GM one (74124) to provide necessary offset.

4. The SK2X transfer-case shift kit was heavily modified for use with the Delica controls. The SK2X was chosen as it provides a lot of tune-ability. After a few tries and drilling an extra hole, the optimum position was established. Only one of the two OE control cables was needed to actuate the NP231.

The SK2X was reinforced to reduce flex. An additional mount to the transmission and a cable mount were added. The original bronze pivot point bushings were replaced with larger more robust ones, with up-sized hardware to make everything work.

5. The first shift lever we made was found to interfere with the drive shaft (oops, I forgot to check that). A shifter arm was fabricated to eliminate the interference. Mounting provisions for the neutral safety switch linkage were also added.

6. The neutral safety switch/transmission encoder sends signals to the dash, enabling the car to only start if “P” or “N” and also illuminates the gear selected on the dash. GM locates their neutral safety switch at the shifter, while the A44D has it located on the transmission gear selector shaft. To avoid a re-wiring nightmare, the original switch was re-used. This was done by adding a 4-bar link mechanism to the 700R4 gear selector shaft to actuate the neutral safety switch. When the shift lever is moved, it pulls the linkage in-turn moving the original switch accordingly. The switch was mounted to a custom bracket which mounts to the transmission.

7. A tandem front mount transmission cooler was added to avoid using the internal radiator heat exchanger. This will ensure no possibility of cross fluid contamination in the event of a leak. The cooler is mounted to the bull bar, and and be easily removed with out disconnecting lines, allowing the bumper to be removed without making a mess. The cooler the transmission stays, the longer it will last!

8. A puller fan was also added tot the stock transmission cooler to further reduce temperature. This was wired to a 50C snap disk for control (top left of cooler).

Engine Bay & Fitment:

Fitting the R2.8 into the Delica Engine bay is a is a tight squeeze.

1. To get a little more vertical clearance a 1/2″ body lift was added. This drops the front sub-frame providing just enough extra clearance. The lift was done by simply adding blocks of 1/2″ aluminum stock between the frame and sub-frame, along with longer hardware. This will actually help to correct the some of the wonky suspension geometry that results from running the 1″ upper ball-joint spacers as the sole means of lift on our rig.

The front sub-frame bolts (M14X1.5-50) were replaced with longer grade 10.9 bolts (M14X1.5-70), yellow zinc coated like OEM.|

The rear sub-frame stud plates were replaced with longer grade 10.9 bolts (M12X1.5-120).

2. The AC compressor was a little too close to the right side frame. To add a little clearance ,the extra mounting lugs on the AC compressor were cut off.

3. The air inlet was fount to interfere with the “bump-out” from the battery compartment. This bump was simply massaged outboard with some persuasion from a hammer. Bumping out the opposite way has no side effects on other systems.

4. The front differential mount was found to interfere with the oil pan. It was trimmed down and rebuilt for a tighter fit to provide necessary clearance.

5. This was also a good opportunity to replace the thermo-acoustic engine bay insulation. The sad OE insulation was replaced with 3/4″ thick Dyna-mat hood insulation. Hopefully this reduces cabin noise & heat.

Motor/Driveline Mounts:

Cummins recommends 3 point mounting, similar to the stock setup. Two motor mounts up front and a single transmission support at the rear.

To reduce risk a fully bolt on solution was designed. This has two benefits. The first is that no welding to the chassis is needed, meaning that nothing internally or externally will need to be re-coated to prevent rust, a huge plus. The second is that if any of the mounting locations or geometry needs to change, and new system can simply be bolted in place, no cutting/grinding of welded-on structure.

1. Starting on the engine side. The right hand side Axis industries motor mount was found to interfere with the AC compressor by about 1cm. When I brought this to their attention they said I needed to buy their $1500 AC compressor relocation kit….. The mount was cut down to provide necessary clearance, then welded and re-drilled with a new mounting hole.

2. The rear cross member (which has the OE motor mounts) was cut and modified to be symmetric, or at least more symmetric. The driver’s side is offset and interfered with the new R2.8 RH starter location. The offset portion was cut out and new tubing welded in place. Thick walled (.120″) 1.75″ OD DOM tubing was a prefect match for the cross member tubing.

3. The motor mounts were made to bolt on to 3 existing locations on the chassis: the original motor mount, sub-frame differential mount and sub-frame chassis mount. 1/4″steel plate and some square tubing was used to fabricate the motor mounts.

4. A new transmission mount was fabricated to work with the original chassis-side bushings. An off the shelf Chevy Nova 700R4 bracket was heavily modified to fit the Delica setup. The 700R4 is supported from the bottom, unlike the A44D which is hung from above.

Systems Integration:

1. The R2.8 comes with it’s own vacuum pump with a 10mm male hose barb. Conveniently this matches the original hard-line that supplies the brake booster with vacuum. 10mm silicon vac line was routed over the radiator to make the connection.

2. An M12X1.25 to 1/8″ NPT adapter is used to reduce the fitting on the thermostat housing to accept the original Delica AC cut-out temperature sensor. An additional ground connection had to be made to the single wire sensor, since the thermostat housing is plastic and therefore has no ground.

The Adapter fitting was bored out to accommodate the original sensor.

3. Unfortunately the original power steering hose was a tiny bit too long to keep. A reducer fitting (M16X1.5 to M14X1.5) was added to the high pressure power steering line. This reduces the M16 banjo fitting on the R2.8 power steering pump down to the M14 size. A banjo fitting with 6AN was added and a new custom high pressure line was made using SS and nylon braided PTFE high pressure line.

The adapter fitting was first bored out to 5/16″ to better match the rest of the system and reduce restriction.

Sealing washers were used at each junction.

The Low pressure return line was also replaced and a Magnefine magnetic filter added in line. For $20 it seemed like a good idea to preserve the new pump. Who knows what kind of junk might be in the system after 30 years.

4. the ECU was mounted on vibration isolators behind the battery compartment. Holes were cut in the fire wall to feed the connectors through. A nice braided grounding strap was made to keep the ECU grounded. A vented cover was 3D printed for a nice looking interior.

5. A brand new full 3″ 304 Stainless steel exhaust was fabricated for the new setup. This exhaust uses a chambered muffler and V band clamps. The exhaust tip was cut an modified for the skewed exit angle. The exhaust hangers are also 304 SS. Thanks to @matcha.the.delica for the TIG welding!

6. The R2.8 comes with a remote oil filter setup. The oil filter was located under the battery compartment with a custom bracket and some extra riv- nuts on the chassis/body. It is a tight squeeze as usual, with a little notching of the fender liner for the lines. An extra 10AN 90 fitting was used to extend one line just enough to make the run. Cummins does not recommend extending the oil filter lines in any way, so hopefully the 1-2″ of fitting will have no impact. The oil filter is vertical with easy access from underneath for an easy oil change.

7. With no more space left in the engine bay, the fuel filter assembly was squeezed in next to the transfer case. It is a tight fit as usual, but this allows the filter to meet the height specs from Cummins. This was tricky as the filter is supposed to be located in-between the tank and lift pump, but the lift pump is low mount, so an annoying constraint.

8. The transmission kick down cable is mated to the original throttle cable with a custom machined linkage. The linkage is fully tunable to adjust shift points.

Radiator & Cooling

1. To effectively cool this new engine a bigger radiator is needed. The aluminum radiators offered for the L300 are only 2 row and are ridiculously expensive (~$380), are known to have quality issues and often ship from overseas. The inlet and outlet of the L300 radiators are also grossly undersized for this application, which would lead to restriction and poor flow. Both inlet and outlet diameter would have to be reduced by about 1″, not great.

After a great deal of digging around it was found that an early 70’s Dodge Ram Charger/Challenger (and other Mopar) radiator was almost the exact same size as the stock radiator, with 3 rows and only $150! A 4 row is also available if we ever need to upgrade. The cores were almost Identical (L x W x H) when compared with the stock copper/brass radiator. The larger end tanks added about 1.5″ of height, this is mostly on the edges of the radiator. The stock radiator end tanks shrink down at the ends, where the Mopar one does not. The mounting flanges on the Mopar radiator also added to the width, but those were easily trimmed to accommodate the pass-thrus and other stuff on the Delica chassis. The drain and transmission heat exchanger lines are also in almost the same spot.

You have probably heard people say that electric fans don’t move enough air. I would be willing to bet they never calculated and matched or exceeded OE CFM. Cheaper kits are failure prone and known to under-deliver. This is why we spent the big bucks and went with this premium kit from Derale. This single speed kit moves 3,750 CFM. This closely matches our calculations for CFM. We get ~3,800 CFM @ 4200 RPM, assuming the fan clutch if fully locked up. So we get full CFM no matter the engine RPM (perfect for those low RPM climbs)! Calculations for the OE fan below:

See the Electric Fan Install Page for more details & calculations

2. The original lower radiator mount was cut off and removed to accommodate the extra 1.5″ of height on the edges of the end tanks.

3. The original condenser brackets were used to mount the radiator. They were trimmed and mounted to their opposite sides (LH bracket->RH side). The flanges were trimmed as needed to accommodate all of the pass-thrus (brake booster, heater core, brakes, etc.). Brackets were fabricated to use the original rubber isolators. Riv-nuts were put into the radiator flanges. The radiator mounts ~1.5″ forward of the original location. The upper radiator mount piggy backed off of the original upper radiator mount location to a foam lined clamp.

4. The two fans were wired separately with 10Ga wire and high current connectors for a maximum reduction in voltage drop. The will later be wired to their own separate relays.

5. The upper radiator hose was constructed using off-the-shelf silicone pre-bends. This yielded nice routing, with smooth bends and plenty of service loop/vibration isolation. The hose coupler included a 1/8″ NPT bung for our VDO water temp gauge. The coupler was then modified to include an M16 Bung for the OE dash temp sensor, and a grounding lug.

6. With limited space up front, an air to water intercooler was implemented. The core is located behind the head on a custom transmission mounted bracket. A pair of Yamaha YZ250 dirt bike radiators were mounted up front to reject the heat. A universal power steering reservoir was modified (hose bung added, breather hole plugged) to be used as the coolant reservoir for this closed loop intercooler system. This was located where the original glow plug relays used to be. Finally a Bosch supercharger water pump from an AMG Mercedes was used to circulate coolant.

7. To increase airflow, Aluminum scoops were fabricated and 4″ puller fans were added to each of the radiators. The fans are IP67 rated, so they should hold up to the elements.

8. Unfortunately after all that effort the AWIC did not have the cooling capacity to keep up with steep grades at highway speeds. The whole system quickly became heat soaked as soon as a steep grade was met. The AWIC did work on flat highway and for city driving. Intake manifold temperatures were over 212F on the steep highway climbs.

So the AWIC system was scrapped and replaced with a traditional air-to-air bar & plate intercooler. Unfortunately no COTS intercooler options were found to fit the front of the Delica, so a semi-custom intercooler was fabricated using a Vibrant core and custom end tanks with rear exits.

2.5″ tubing was routed through the under-seat compartment and through where the original air feed tube ran under the fender. Tubing was then ran to the front to the radiator

The air-to air intercooler was found to reduce under-load intake temperatures by around 100F over the AWIC, holy cow!

9. To make room for the 2.5″ intercooler tubing on the passenger’s side, the front heater core lines needed to be relocated, but to where?… The only sensible option was to route these lines over the top of the radiator. this is a bit higher than they should be, but there were no issues with trapped air. SS braided line was used since it has a much tighter bend radius, and there was plenty leftover from gutting the AWIC. I wonder what the performance gains from using braided lines for the heater core are?

Drive Shafts:

1. We will need front and rear custom drive shafts to adapt the Jeep Transfer Case (1310 size) to the stock Delica differentials. We will incorporate a dual cardan joint in the rear shaft. This will enable us to push the transmission higher, in contrast to the stock setup, which hangs low. The dual cardan can handle the greater drive shaft angle. This will be a challenge to incorporate into an already short telescopic drive shaft. Below are the concepts.

Thanks to Brian at Driveline Tech in Utah for fabricating our Custom Drive shafts. The only difference from the above schematics is the diff-side yokes. Those were made using blank flange yokes instead of the FY131098 (since they are discontinued), drilled to match with “hub-centric” style rings to mate with the pinion flanges.

2. With the rear drive shaft installed there is an 8 degree angle at the pinion U-Joint. The operating angle of this U-joint should be as close to 0 degrees as possible. When not operating the angle should be around 2 degrees to account for axle wrap (this is a jeep “standard”). To achieve this, caster wedges were used to get the U-joint angle to 2 degrees.

A few 3D printed caster wedges were installed to establish some data points. These were graphed and a trend-line added to extract an equation (good old Y=mX+b). Plugging in the desired pinion angle (2 degrees) results in the caster wedge angle needed. The result was 2.7 degrees. This was rounded down to 2.5 degrees, since that is an available wedge size. This also assumes that axle wrap may be above 2 degrees, which is probably likely given the rear leaves are soft and the power going to the axle is now double OE. We may make custom wedges later on depending on performance and axle wrap.

Note: The Delica pinion is long, so small caster angle changes have an amplified impact on drive shaft angle. This is why a 2.7 degree caster wedge corrects for 6 (8-2) degrees of shaft angle.

Electrical and Wiring

1. The first thing we did was add our own fuse/relay box. This is located where the original coolant tank was. It can be un-bolted and moved out of the way (just like the coolant bottle) for battery replacement.
2. The fuse box contains:
   -2 Relays for the fans, 35A
   -2 Relays for aux lamps, 20A
   -1 Relay for the transmission lock-up solenoid, 10A
   -1 Relay for the intercooler water pump & fans, 20A Not anymore…

3. The main cabin wiring loom was routed forward of the engine and up through a blank panel in the floor. There was a perfect unused location stamped in the floor. This wire loom connects the ECU to the diagnostic port, status lamps and the supplied accelerator pedal.

4. Keeping the Original Cluster was a requirement for this build, both for aesthetics and functionality. The original cluster was modified to include the check engine, warning and wait-to-start status lamps provided buy the ECU. The seatbelt, water-in-fuel and trans temp lamps were replaced with the new ECU lamps since that are no longer functional. Yellow LEDs and clear lenses were used in the original locations. Montero bulb holders were modified to accept the LEDS

5. The accelerator pedal became its own fun mini-project. The R2.8 includes a drive by wire pedal, However it is bulky and would require a lot of work to get it to fit (pulling the entire dash, relocating the fuse box, cutting&welding unibody, etc.). To avoid this hassle the sensor from the supplied pedal was adapted to fit the original Delica pedal. This retains the original throttle cable (used for transmission kickdown) and the throttle lock.

To get the new sensor up and running the sweep (range) of the original pedal was measured using an Arduino and some basic code. This enabled accurate adjustment of the linkages on the Delica pedal. A 3D printed gear box was designed to amplify the sweep, as to keep the size of the 4 bar link reasonable.

6. The original tachometer mechanism was replaced with a more modern Stepper Motor. Here, an X27-168 stepper motor was mounted to a 3D printed adapter plate. The X27-168 is a common stepper motor and is used in gauges in motorcycles and cars alike, most notably GM. This motor is controlled with a an Arduino and TB6612 driver. This stepper motor is actually small enough that it can be run directly off of the Arduino, but with the loss of speed control, so the TB6612 was chosen as a cheap add-on to enable speed control when writing the code. This yielded smoother step motion of the tachometer needle.

The Arduino reads the tachometer pulse signal supplied by the R2.8 ECU. Unfortunately the ECU supplies a 6V signal, so a voltage divider circuit was made to drop the tachometer signal voltage down to 5V so it would not damage the Arduino, which uses 5V logic. This was made with one 1k Ohm and two 10k Ohm resistors.

7. The stock speedometer and odometer was also retained thanks to this super niche product from Dakota Digital! This slick unit takes in the signal from the electronic tail shaft speed sensor (a requirement for running the Terraflex slip yoke eliminator) and uses it to drive a mechanical speedometer with full PID control. It is fully adjustable with bluetooth and smartphone app! now we will have an accurate speedometer no matter the tire size.

A ford style clip on cable was found to fit the Delica cluster input shaft perfectly. It was trimmed down and secured with a hose clamp.

The waterproof module was mounted on the bumper beam, where the original oil cooler used to be. This results in a short run with minimal bends.

Seriously awesome that this product exists. Having to build my own hardware of this pedigree would have been a major project.

Air Conditioning

1. All of the original AC system was reused with the exception of the compressor hoses. The original front condenser & fan was mounted farther forward with custom brackets.

2. The condenser routing was flipped in order to provide better hose routing. The discharge refrigerant liquid enters the tandem condenser (passenger side) first and then the front mount condenser (reverse of OE). A new line to connect the condensers was made by welding the OEM tubing.

3. New custom hoses were made for the new configuration. Interestingly all of the AC fittings on the van are English size. #10 size hose was used for the suction line and #8 size for the discharge line. Reduced size barrier hose was selected for its slim profile and tighter bend radius. It is generally easier to work with smaller hose. The appropriate fittings were ordered an the runs were established. The in-line service ports have been located in front of the condenser for easy access. The hoses were then crimped by my local hydraulics shop.

It was also surprisingly inexpensive to make the hoses. Both hoses were only $190 combined for parts and crimping labor.

4. A new filter drier was installed as well. See R12 TO R134A AC CONVERSION for details.

Special Notes

I figured I would add this section since this project has generated a lot if interest and questions from those who may want to do something similar. Below are some nuances and lessons leaned after completing the project:

1. The R2.8 has unfortunately been updated sometime in 2021-2022. Thankfully I got the early version. This update changed the oil cooler housing and relocated the oil filter to the back of the oil cooler, instead of the original remote setup with hoses. Even with the smallest filter this new setup drops that location about 4in lower. This is a big problem since that is exactly where the front differential and drive shaft is. For reference, there is only about a 3/8″ gap there (with 1/2″ body lift) on our build. There are remote mount kits available, but it looks like a serious body lift would be required to accommodate them. Maybe a custom low profile version could be made or utilize the oil cooler delete from Quick Draw for remote mounting. I think the best option would be to replace those oil cooler/back plate components with those from the early generation. The new filter location with small filter shown in red:

Another thought on this issue is to relocate the front differential to the right hand side of the car, instead of the left. This can be done simply by bolting the intermediate shaft to the other side of the differential and flipping the axles. Intermediate shaft bracketing will probably have to be tweaked along with subframe clearance. One would then run a transfer case with a right hand drop

2. With all the power the original final drive short gearing (1:4.875) is not great on the highway. I would say the minimum tire size one should run would be 31″. So ya, a suspension lift in addition to the body lift is a must. With 31in tires and a 0.7 OD (700R4 4th gear), this yields 65MPH at around 2500 RPM. The RPM with this gearing is still unnecessarily high, especially when doing 75-80 MPH. The best (not easiest) solution is to swap the front diff to an 8″ size and run the available 1:4.222 gears in the front and rear, which is what I chose to do. Details on re-gearing here: Gears, LSDs and Lockers

There is also a 1:4.625 gear set available for the OEM 7.25″ small size front diff, but its not much of an improvement over the 1:4.875 rartio for the hassle. Or break out the sawzall and run 33s (easiest).

3. The additional weight of the engine and all of the new sub system components pared with the slightly more forward mounting location of the engine resulted in more sag on the front suspension. The original torsion bars would sag too much even when close to maxed out. One should never max out torsion bar adjustment, it will lead to catastrophic failure and suspension collapse if you hit a bump the wrong way. To address this I replaced the original 19mm torsion bars with the thicker 24mm Hyundai torsion bars. This stiffened up the front suspension and solved the problem. The thicker bars also got rid of the terrifying Delica nose dive during hard braking: