Last Updated: 02/09/2018 @ 08:35 pm
Member Credit: NISformance
This ‘How-To’ gives a description of the steps required to prepare an HR motor for installation in the 2002/2003 Maxima.
Kit & Recommend Parts (click on image to purchase)
FWD HR Engine Swap Kit
EPS Tuning Oil Gallery Gasket/Hardware Kit VQ35 FWD HR Head engine
There are a few things to keep in mind before beginning your swap:
- It’s easier to do this swap if you have a 3.5 DE motor laying around, especially if you just pulled it out of the car. You will need to take some things off of the old motor to use on the HR. Without this, there are a few parts that you will have to buy in order to complete the swap.
- There are some specific tools needed: An ‘E8’ torx socket, 5/16 Allen key, Loctite
Step 1: Stripping the motor
Depending on where your motor came from, there may be a lot of ‘extra’ pieces still attached to it. Some of these will just get in your way while you prep your motor, some can’t be used for this swap.
- Remove all accessories, which includes the alternator, power steering pump.
- Remove any harnesses and brackets that are still connected to the motor.
- Remove upper intake manifold (removing lower manifold is not necessary, but sometimes desirable. If removed, a new gasket should be used to reinstall).
- Remove oil temperature sender:
- Remove idler pulley/tensioner ‘spacer’ (seen below in red):
** The injector rail may also be removed, but that isn’t necessary.
Step 2: Cover any openings
There will be A LOT of metal shavings and dust around the motor, depending on how you do the cutting and grinding that comes later. These absolutely CANNOT be allowed to get into the motor.
- intake ports in the top:
- exhaust ports on the sides of motor:
- fuel injector ports if fuel rail was removed:
- the open ends of any coolant hoses/pipes:
Step 3: Modifying the motor
Some parts of the motor will need to be cut somehow (tools, methods and results will vary) to allow for proper fitment and function once it’s reinstalled.
** Because of some concerns about the integrity of the stock oil gallery gasket, we at NISformance strongly recommend replacing it in this step. **
- when changing the oil gallery gasket, this is a good time to grind away the center portion of the power steering bracket before reassembling the front of the motor.
- grind/cut away the center portion of the power steering bracket. This requires some aggressive cutting, but also needs some attention to detail (cutting too DEEPLY can weaken the integrity of the timing cover. Cutting too WIDE can weaken the remaining brackets that will be needed to hold the alternator):
- grind/cut away a portion of the metal where the idler pulley/tensioner spacer was:
- remove exhaust manifold studs at the rearmost exhaust port (close to the trans). This requires an ‘E8‘ torx socket:
- clean out the threads in the opposite holes using a ‘10×1.25‘ tap.
- replace the removed studs into the newly cleaned holes:
- remove lower oil pan.
- remove upper oil pan.
- use the oil pan from a 3.5 DE motor…but remove the windage tray. Add your o-rings and seals, and install upper oil pan onto the HR motor.
- remove the HR water pump access cover, and replace it with the one from the DE motor
Step 4: Adjusting the cam signal wheel
This is a VERY important step and it must be done very carefully for your car to run properly. You have to be accurate.
Apart from the wiring, adjusting the signal wheel is the most detailed work you need to do on the swap. It is important to be very accurate when cutting or grinding, and it’s also extremely important to assemble everything correctly at the end of this step. Pay close attention to the pictures and make sure that your work looks EXACTLY the same!
*You will need to modify your 5/16 Allen key by cutting the arm down so that it is approximately 3/8″ long. This is your ‘special tool’ that you will need to use in this part of the swap.
- open one of the valve covers.
- using the ‘special tool’, loosen the signal wheel lock nut and remove the signal wheel from the intake cam:
- completely remove the inner nubs from the signal wheel without damaging the rest of the inner surface:
- at the crank, turn the motor until two notches are visible at the top of the cam:
- add Loctite to the flat inner surface of the signal wheel:
- reconnect the modified signal wheel to the intake cam…be sure to place it at the proper angle (as shown below) and resecure the lock nut:
- close and bolt down the valve cover
- open the other valve cover, and repeat these same steps.
Step 5: Cam Sensor Wiring
Now that all of the heavy wrenching is out of the way, we get to the really important part of your swap. The wiring harness in your car needs to be connected to the newer motor, and it’s not just a ‘plug-and-play’ situation. These diagrams show you the changes that need to be made to make your DE harness control your HR motor:
** THESE WIRE CONNECTIONS ARE CRITICAL. MAKE SURE THAT THEY ARE CONNECTED CORRECTLY (ACCORDING TO THE INSTRUCTIONS), AND SECURELY. TWISTING THEM TOGETHER IS NOT GOOD ENOUGH. **
The stock cam signal wire will be intercepted (cut) by the cam signal inverter supplied with the swap kit. There are six wires on the cam signal inverter…here’s how you connect them:
- the RED wire goes to a 5v source from your car’s harness (to supply power to the sensor)
- the BLACK wire is ground
For Cam #1…cut the existing wire:
- the YELLOW inverter wire connects to the existing wire on the CAM side
- the ORANGE inverter wire connects to the existing wire on the ECU side
For Cam #2…cut the existing wire:
- the BLUE inverter wire connects to the existing wire on the CAM side
- the GREEN inverter wire connects to the existing wire on the ECU side