2.5L Ford Fusion Engine Swap

Why would anyone want to swap from an L3-VE to an L5-VE engine?
  1. Cost considerations
    • Ford parts are usually less expensive and sometimes 3-7 times less expensive than Mazda parts.
    • Ford Fusion engines are less expensive and more available
    • Ford Fusion engines are more likely to be available with lower miles
  2. The 2.5L engine makes more power
    • 2.5L Bored to 89 mm from 87.5 mm
    • 2.5L Stroked to 100 mm from 94 mm
    • 2.5L Increases torque to 167 from 154
    • 2.5L Increases horsepower to 170 from 151
  3. The 2.5L engines appear to have some longevity fixes
    • Different bore liner construction (4340 steel-molybdenum alloy)
    • Have crankshaft friction washers (only missing on the earlier Mazda 3s)
    • The oil pan has more capacity since the AC compressor isn't mounted there (only if you retain the Fusion acessory layout)
    • The PCV air/oil separator bolted to the engine block has a longer fin that may help keep more oil out of the intake. Several manufacturers are having issues with their aggressive scavenging of crankcase vapors using engine vacuum. The result of excessive oil collection can be trouble.
      • Liquid oil accumulating in the intake manifold
      • Backside of throttle plate is always dirty
      • Intake runners become gooey with oil and dirt
      • Intake actuators become stuck
      • Excessive oil reaching the exhaust valves can coke the valves and cause them to stick open
      • Oil is being burned without the owner being aware, which can cause the engine to starve for oil if not checked often
  4. The 2.5L engine uses a spin-on oil filter, rather than a filter cartridge

My 2.5L Ford Fusion Engine Swap Strategy

There is more than one way to do this swap. The more common way is to use all of the 2.3L accessory drive parts. I didn't do that for the following reasons:
  1. The 2.5L engine has a better accessory belt layout
    • Only a single accessory belt
    • Shorter crankshaft pulley
    • No cutting of the A/C belt and messing with stretching the new one on
    • AC Compressor on the 2.5L doesn't steal oil capacity out of the oil pan
      • The Fusion oil pan has a capacity of 5.3 quarts vs. 4.5 quarts in the Mazda 3 oil pan
      • The Mazda AC Compressor bolts to the bottom of the hot oil pan, which doesn't help the A/C work better
  2. Improved exhaust layout
    • The Fusion exhaust manifold and midpipe can be removed without having to remove the engine
    • The Fusion doesn't use a "manicat" integrated manifold and catalyst
  3. Breaking seals
    • I didn't want to replace the oil pan seal since my donor engine was tight and dry
    • I didn't want to replace the front cover and seal since my donor engine was tight and dry

Parts Usage

  • Parts used from the 2.3L Mazda 3
    • Coils. The connector on the Fusion part is not compatible
    • Camshaft cover. Since the Mazda coils must be used, the camshaft cover must be used because:
      • The fastener holes in the Fusion camshaft cover don't come close to lining up with the Mazda coils
      • The height of the coil mounts are different on the Fusion camshaft cover
      • The Fusion camshaft cover has a hole in the center for a head temperature sensor that is unused by the Mazda ECM
    • Crankshaft position sensor. The 2 wire connector on the Fusion part is not compatible with the 3 wire Mazda 3 connector
    • Oil pressure switch. The connector on the Fusion part is not compatible
    • Coolant outlet at engine block. The Fusion part lacks a water temp sensor, although the Fusion part could be tapped to use the Mazda sensor
    • Intake manifold
      • The Fusion intake has larger ports
      • The Fusion intake has different throttle body mounting bolt locations
      • The Fusion intake lacks vacuum-actuated tumble valves
      • The Fusion intake has a similar crankcase ventilation hose, but uses different fittings
    • Electronic Throttle Body
      • The connector on the Fusion throttle body is not compatible
      • Even if the Fusion throttle body could be rewired, the electronic interface is not compatible with the Mazda ECM
      • The Fusion throttle body doesn't have coolant line provisions
      • The Fusion throttle body draws more current than the Mazda PCM can deliver
  • Parts used from the 2.5L Ford Fusion
    • Engine long block
    • Engine front timing cover
    • Engine oil pan
    • Complete accessory drive layout and components
      • Water Pump
      • Tensioner
      • Both idler pulleys
      • Crankshaft pulley (Modified tone wheel)
      • A/C Compressor (Modified lines)
      • Alternator (Modified Wiring)
    • Alternator
    • A/C Compressor
    • Accessory drive pulley
    • Accessory drive tensioner

2.5L Ford Fusion Engine Differences

The presumption is that I'm trying to use the 2006 Mazda 3 wiring harness and PCM with the 2.5L Ford Fusion engine.

Coil Pack Differences:
   The 2.5L coil packs have 2 wire connectors while the 2.3L coil packs use 3 wire connectors
   The 2.5L coil pack is shorter and the mounting boss is thicker
   The 2.5L coil pack boots can be transferred to the 2.3L coil packs, but the wire connector rubs the cam cover
   It looks like the 2.3L coil packs could be used on the 2.5L engine by using a washer between the cam cover and the coil pack
Choice: Use the 2.3L coil packs

Timing Cover Differences:
   The 2.5L timing cover has a protrusion to the right of the engine mount attachment point. This doesn't have any apparent impact on the swap.
Choice: Use the 2.5L timing cover

Cam Cover Differences:
   The 2.5L cam cover has shorter threaded pedestal mounts for the coil packs    The 2.5L cam cover coil pack mounting pedestal mounts are in slightly different locations
   The 2.5L head has a head temperature sensor the 2.3L does not
Choice: Use the 2.3L cam cover
Choice: Cut a hole using a forstner bit to accomodate the existing 2.5L head temperature sensor, connector, and weather seal

Accessory Drive Layout Differences:
   The 2.5L Air Conditioning compressor is on the intake side of the engine and mounts in the 2.3L Alternator Location
   The 2.3L Air Conditioning compressor mounts under the oil pan
   The 2.3L Air Conditioning drive belt is a stretch-to-fit belt that must be cut to remove it or the accessory belt behind it
   The 2.5L belt is a single belt with spring tensioner design vs. two belts on the 2.3L Mazda 3 engine
Choice: Use the 2.5L drive belt layout
Choice: Use the 2.5L AC Compressor
Choice: Use the 2.5L Oil Pan and Pickup

Alternator Differences:
   The 2.5L Alternator has a 3 wire connector
   The 2.5L Alternator has a different case and mounting points
   The 2.5L Alternator is on the exhaust side of the engine and mounts on two M10x1.5 studs plus one M10x1.5 x 94.5mm bolt
Choice: Use the 2.5L Alternator
Choice: Source the alternator cooling parts from a Fusion

Crankshaft Damper/Pulley/Tigger Pulse Wheel Differences:
   The 2.5L damper/pulley has a single "window" that does not match the 2.3L trigger wheel
   The 2.3L damper/pulley has three windows
   The 2.5L crankshaft position sensor uses 2 wires and the 2.3L uses 3 wires
   The 2.5L crankshaft pulley doesn't have groves for the AC Compressor for the 2.3L
Choice: Use the 2.5L Crankshaft damper/pulley, but cut 3 windows into the trigger wheel and weld on one additional tooth to fill the 2.5L window that is misplaced
Choice: Use the 2.3L Crankshaft Position Sensor

Intake Differences:
   The 2.5L intake has larger ports
   The 2.5L intake has different throttle body bolt mounting locations
   The 2.5L intake lacks vacuum-actuated tumble valves
   The 2.5L intake has a similar crankcase ventilation hose, but uses different fittings
Choice: Use the 2.5L Mazda 3 Intake Manifold that has tumble valves

Throttle Body Differences
   The 2.5L throttle body has different bolt hole locations than the 2.3L
   The Ford 2.5L throttle body doesn't have coolant line provisions
   The 2.5L throttle body draws more current than the Mazda PCM can deliver
Choice: Use the 2.5L Mazda 3 throttle body that has coolant line connections

Other Differences:
   Use 2.3L Oil Pressure Sensor
   Use 2.3L coolant hose distribution block
   Use 2.5L Fuel Injectors

2.5L Ford Fusion Torque Specifications

FastenerTorqueNotes
All values are dry torque unless noted
Engine Front Cover Bolts (1-18)71-101 in-lbsNotes
Engine Front Cover Bolts (19-22)30-40 ft-lbsNotes
Valve Cover Bolts71-93 in-lbsCris-Crossing pattern
Serpentine Belt Tensioner14-18 ft-lbsNotes
Crankshaft Pulley Bolt1) 76 ft-lbs
*** wait 5 minutes***
2) 1/4 (45 degree) to 1/2 (90 degree) turn past 78 ft-lbs
Notes
Oil Pan Bolts13-17 ft-lbsCris-Crossing pattern
Crank Position Sensor48-60 in-lbsNotes
Cylinder Block Lower Blind Plug14-16 ft-lbsNotes
Flywheel Bolts80-85.5 ft-lbsCris-Crossing pattern, use thread locker
ECT Sensor90-123 in-lbsNotes
Intake Manifold Bolts16-20 ft-lbsCris-Crossing pattern
Axle Nut173.5 - 202.3 ft-lbs32mm Socket
FastenerTorqueNotes
FastenerTorqueNotes
FastenerTorqueNotes
FastenerTorqueNotes

   Last update: Dec 7th, 2019