I've seen it asked before on various Mazdaspeed related social communities, and I've answered to the best of my ability. I've decided to create a thread that contains (hopefully) exhaustive differences that the EcoBoost 4 cylinders found in the Focus ST and RS (2.0 and 2.3) has in contrast to the Mazdaspeed3/6's L3-VDT.
This thread is written under the assumption that the user is familiar with the L3, but not the EcoBoost equivalents. Additionally, this is all based off of my personal experience with both platforms, owning 2 Mazdaspeed3s and a Focus RS, all of varying modification levels from (what most would consider) fully built, to mildly modified, to completely stock; a fair bit of research (any public facing Ford/Ford Performance documentation); and various parts manufacturers. There may be some inaccuracies when it comes to information I'm less personally enlightened to. Additionally, the direct comparisons are to that of a Focus RS and Focus ST. There are differences in the EcoBoost applications between other platforms like the Lincolns, Mustang, etc. but this thread is direct comparison to the C-chassis hot hatches with EcoBoosts.
Starting from the bottom-end.
Block:
- The speed engine and 2.3 uses an 87.5mm x 94mm bore and stroke. and 2.0 uses 87.5mm x 83.1mm.
- The 2.3 EcoBoost is a fully open deck design. This is the primary contributing factor to the comparatively lower power threshold for RS engines.
- Small casting geometry differences. The engine mounts put the EcoBoost engine at a steeper angle to pull down the engine's center of gravity. This is done by the actual provisions on both the timing cover and transmission, not the mounts themselves. On that, the EcoBoosts use 3 studs for the passenger motor mount, vice the MZR's 2.
- There is slight differences in the alloys used between the MZR and EcoBoosts, causing the 2.0 blocks to develop stress cracks under high power applications, despite maintaining the same bore.
- Block deck height for all 3 is 231mm.
Rotating Assembly:
- The 2.3 EcoBoost uses 7mm shorter rods; 143mm vice the speed family 150mm rods. This lowers the compression from 9.5:1 to ~9.4:1, and seems (from my eyes) to be what allows the 2.3 and 2.0 EcoBoosts to take advantage of 55* of timing advance.
- The 2.0 EcoBoost uses 5.8mm (155.8mm) longer rods, to accommodate it's destroked nature. The compression ratio is ~9.3:1 in this application.
- The EcoBoost engines use lighter crankshafts, with smaller counterweights. In the 2.0 application, the rod journals have longer offset from the crank centerline to accommodate the longer rod length.
- Piston design is different between each application. Even between gen 1 and 2 MZRs dish design was revised. The primary differences in dish design between gen 2 MZRs and EcoBoosts is valve relief, though some subtle dish differences do exist.
Timing:
- The MZR uses 2 sprockets to drive the timing chain and oil pump. The EcoBoosts switch to a single duplex sprocket (meaning there's 2 sets of teeth) to run both systems. This pulls down the friction washer requirement for the timing system down by one.
- The MZR uses single bank variable valve timing (on the intake bank), the EcoBoosts use VVT on both banks.
- The EcoBoost uses thicker teeth for the entire timing system.
- EcoBoosts use a duplex 4-rib crank pulley, to run the A/C separate of the rest of the accessory drive. The MZR uses a simplex 6-rib crank pulley. Between both applications, the alignment hole is the same as well as the trigger configuration of 60-2.
- MZRs have a maximum timing advance of 44*. The EcoBoosts have a maximum advance of 55*. This is due to the rod length differences (contrary to the piston dish designs, as many people would be led to believe).
Head:
This is where the largest differences are found.
- MZRs use 4 discrete exhaust ports with a provision for exhaust gas recirculation in the head. In the EcoBoosts, this is changed to a headifold design (all 4 exhaust ports collect inside the head with a single exhaust exit). Additionally, the EcoBoost creates a provision for an exhaust gas temperature sensor.
- Mentioned before, but the EcoBoosts use dual bank variable valve timing. With this, there is a difference in casting for a 2nd oil control solenoid for the VVT system.
- MZRs use the intake bank to run the high pressure fuel pump using one of the lobes. On the EcoBoosts, the fuel pump is relocated to the exhaust bank, with the intake bank being used for a vacuum pump.
- The MZR uses 9.1mm of valve lift and 245 degrees of duration for intake, and 7.7mm and 227 degrees for exhaust. The 2.0 and 2.3 both use 8mm x 234* intake and 6.99mm x 224* exhaust.
- The MZR uses 35mm valve diameter on intake, 30mm on exhaust. The 2.0 uses 32.5mm; 28mm, and 2.3 uses 32.5mm; 30mm.
- The EcoBoosts use different injector ports than the MZR does, as well as a slightly different fueling system for direct injection altogether; they run at close to the same pressures but achieve pressure and injection through different means.
Miscellaneous Notable:
- The EcoBoosts use different sump geometries, as the hot-side piping from the turbocharger is an under-route setup.
- The EcoBoost engines adopted the use of an inline oil feed filter for the turbochargers.
- The oil pump has been updated in the EcoBoosts to up the pressure and flow slightly.
- The MZRs use a 4-2-1 exhaust manifold design. As previously discussed, EcoBoosts don't use an exhaust manifold. This feeds into the respective platforms turbocharger.
- (Turbocharger dimensions for each engine will be added here soon)
For strictly the engine, that should be most of the differences between the engine applications. It's a clear lineage between the 3 engines, and hopefully this will help anyone who is looking for more technical differences between the engines.
As a final thought, I personally cannot validate a lot of information specific to the EcoBoosts. While this is made to the best of my ability, I do not own a 2.0 EcoBoost, and my RS is stock. If any information in this is incorrect, please do not hesitate to send me a message and I will update this thread as appropriate.
This thread is written under the assumption that the user is familiar with the L3, but not the EcoBoost equivalents. Additionally, this is all based off of my personal experience with both platforms, owning 2 Mazdaspeed3s and a Focus RS, all of varying modification levels from (what most would consider) fully built, to mildly modified, to completely stock; a fair bit of research (any public facing Ford/Ford Performance documentation); and various parts manufacturers. There may be some inaccuracies when it comes to information I'm less personally enlightened to. Additionally, the direct comparisons are to that of a Focus RS and Focus ST. There are differences in the EcoBoost applications between other platforms like the Lincolns, Mustang, etc. but this thread is direct comparison to the C-chassis hot hatches with EcoBoosts.
Starting from the bottom-end.
Block:
- The speed engine and 2.3 uses an 87.5mm x 94mm bore and stroke. and 2.0 uses 87.5mm x 83.1mm.
- The 2.3 EcoBoost is a fully open deck design. This is the primary contributing factor to the comparatively lower power threshold for RS engines.
- Small casting geometry differences. The engine mounts put the EcoBoost engine at a steeper angle to pull down the engine's center of gravity. This is done by the actual provisions on both the timing cover and transmission, not the mounts themselves. On that, the EcoBoosts use 3 studs for the passenger motor mount, vice the MZR's 2.
- There is slight differences in the alloys used between the MZR and EcoBoosts, causing the 2.0 blocks to develop stress cracks under high power applications, despite maintaining the same bore.
- Block deck height for all 3 is 231mm.
Rotating Assembly:
- The 2.3 EcoBoost uses 7mm shorter rods; 143mm vice the speed family 150mm rods. This lowers the compression from 9.5:1 to ~9.4:1, and seems (from my eyes) to be what allows the 2.3 and 2.0 EcoBoosts to take advantage of 55* of timing advance.
- The 2.0 EcoBoost uses 5.8mm (155.8mm) longer rods, to accommodate it's destroked nature. The compression ratio is ~9.3:1 in this application.
- The EcoBoost engines use lighter crankshafts, with smaller counterweights. In the 2.0 application, the rod journals have longer offset from the crank centerline to accommodate the longer rod length.
- Piston design is different between each application. Even between gen 1 and 2 MZRs dish design was revised. The primary differences in dish design between gen 2 MZRs and EcoBoosts is valve relief, though some subtle dish differences do exist.
Timing:
- The MZR uses 2 sprockets to drive the timing chain and oil pump. The EcoBoosts switch to a single duplex sprocket (meaning there's 2 sets of teeth) to run both systems. This pulls down the friction washer requirement for the timing system down by one.
- The MZR uses single bank variable valve timing (on the intake bank), the EcoBoosts use VVT on both banks.
- The EcoBoost uses thicker teeth for the entire timing system.
- EcoBoosts use a duplex 4-rib crank pulley, to run the A/C separate of the rest of the accessory drive. The MZR uses a simplex 6-rib crank pulley. Between both applications, the alignment hole is the same as well as the trigger configuration of 60-2.
- MZRs have a maximum timing advance of 44*. The EcoBoosts have a maximum advance of 55*. This is due to the rod length differences (contrary to the piston dish designs, as many people would be led to believe).
Head:
This is where the largest differences are found.
- MZRs use 4 discrete exhaust ports with a provision for exhaust gas recirculation in the head. In the EcoBoosts, this is changed to a headifold design (all 4 exhaust ports collect inside the head with a single exhaust exit). Additionally, the EcoBoost creates a provision for an exhaust gas temperature sensor.
- Mentioned before, but the EcoBoosts use dual bank variable valve timing. With this, there is a difference in casting for a 2nd oil control solenoid for the VVT system.
- MZRs use the intake bank to run the high pressure fuel pump using one of the lobes. On the EcoBoosts, the fuel pump is relocated to the exhaust bank, with the intake bank being used for a vacuum pump.
- The MZR uses 9.1mm of valve lift and 245 degrees of duration for intake, and 7.7mm and 227 degrees for exhaust. The 2.0 and 2.3 both use 8mm x 234* intake and 6.99mm x 224* exhaust.
- The MZR uses 35mm valve diameter on intake, 30mm on exhaust. The 2.0 uses 32.5mm; 28mm, and 2.3 uses 32.5mm; 30mm.
- The EcoBoosts use different injector ports than the MZR does, as well as a slightly different fueling system for direct injection altogether; they run at close to the same pressures but achieve pressure and injection through different means.
Miscellaneous Notable:
- The EcoBoosts use different sump geometries, as the hot-side piping from the turbocharger is an under-route setup.
- The EcoBoost engines adopted the use of an inline oil feed filter for the turbochargers.
- The oil pump has been updated in the EcoBoosts to up the pressure and flow slightly.
- The MZRs use a 4-2-1 exhaust manifold design. As previously discussed, EcoBoosts don't use an exhaust manifold. This feeds into the respective platforms turbocharger.
- (Turbocharger dimensions for each engine will be added here soon)
For strictly the engine, that should be most of the differences between the engine applications. It's a clear lineage between the 3 engines, and hopefully this will help anyone who is looking for more technical differences between the engines.
As a final thought, I personally cannot validate a lot of information specific to the EcoBoosts. While this is made to the best of my ability, I do not own a 2.0 EcoBoost, and my RS is stock. If any information in this is incorrect, please do not hesitate to send me a message and I will update this thread as appropriate.
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