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Engine Swap Idea -- Let's Brainstorm

13001 Views 21 Replies 5 Participants Last post by  Thane
Disclaimer: This thread is intended to spark a discussion and could possibly evolve to an actual swap being attempted. Please avoid turning it into an insult-fest or pissing contest. People I'm hoping will join the thread have been through the common swap and have a lot of insight.

Background: I normally find the idea of engine swaps on vehicles built after 1995 to be a waste of resources (time, money, materials) because these later vehicles rely on computerized ignition systems, diagnostic, and emissions systems. I'm also turned off at the plain-Jane, ridiculous engine swaps most car guys do, which is to shoe horn a V8 (typically Chevy) into anything and everything, (IMHO) the dumbest of which is done to air-cooled Volkswagens. That being said, there are some swaps I can appreciate, one of which is the most common in the air-cooled VW world where the current common/popular swap is an older Subaru EJ series engine. One of the more clever I've seen is some series of Fiat engine that works well in an older Beetle. One of the rare V8 swaps that tend to work well is the First Gen Chevrolet Blazers. And then there is the popular 2.5L swap into the Mazda 2.0/2.3L that requires a minimum of parts to be changed.

The idea: I've been keeping a 2.5L swap in the back of my mind after reading several threads and communicating with those who've accomplished it. The process looks involved but isn't that scary (for myself). My vehicle's 2.3L has 164K miles on it and still runs well with minimal oil consumption, which I believe is due to my vigilance in maintenance. One item which I believe is overlooked is the valve cover gasket was redesigned to prevent excessive oil consumption. I caught that just in time during a routine spark plug replacement service when I observed oil soaked threads on #4 and minor soaked threads on #3 . Another indication of a problem was when I proceeded to remove the valve cover to replace the gasket -- several of the fasteners on the driver's side of the engine were loose. Since my vehicle is not in a rust belt state, I don't have the worries of corrosion that would normally preclude spending the money on a proposed swap.

Meanwhile, my mind will occasionally fiddle with the idea of engine candidates and what will be required for the swap. A few days ago, during my evening commute, I glanced over and noticed a Ford Escape in the adjacent lane. I remembered the Escape's engine is one of the more suitable candidates because, for whatever reason, they're cheaper to acquire. I noticed this particular vehicle had a V6 badge at which point my brain started wondering what it would take to put a V6 in my MZ3.

  • Will it fit in the Mazda's engine bay
  • PCM/ECU Requirements
  • Modifying the existing harness to work with the donor PCM/ECU
  • Transmission swap required?
  • Radiator upgrade needed?
  • Front suspension modifications required (extra weight of the engine)?
  • Front brake upgrades required? Again, extra weight of the engine)

If the engine won't fit in the Mazda's engine bay, then this idea is dead.

The donor vehicle's PCM/ECU will have to accompany the engine since the stock PCM is programmed for the stock 4-cylinder. That being said, will it be possible to modify the stock harness to work with the upgraded PCM? I'm thinking the donor's harness accompanies the engine as well as other connectors which feed the various dashboard gauges. That's where splicing and modifying harnesses will come into play and will entail referencing wiring diagrams for both vehicles.

Will the V6 engine bolt to the stock transmission, or will the donor transmission have to be adapted? If so, will the drive axles line up with the donor? That could be the show stopper unless everything is measured before the project is even attempted. Assuming the stock transmission will bolt to the V6, will it need to be strengthened to handle the extra torque? I don't know if the escape came with a manual transmission option, but my vehicle is an automatic. We can discuss both options.

The V6 requires more cooling capacity and may need a larger radiator if the donor's radiator will not fit the MZ3's bay. If the V6 radiator and I4 are similar, then that's money and time saved.

A large engine is going to carry a a few hundred pounds of extra weight, which is one aspect of a large engine most people don't take into consideration. That weight means the front suspension and brakes have to compensate for the heavier load.

Did I miss anything?

I'm just spit balling here since I've not seen any mention of this having been attempted. I'd love to be directed to any links if it has. I'm thinking a MZ3 with the V6 would be a major screamer as well as sleeper. Please daydream about this and throw out ideas.
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My brother is in the shoehorn-a-V8-into-whatever camp. He thinks it's the perfect engine for any car, lol. He's done it and doesn't mind shortening drive shafts, repositioning motor mounts, etc.
The 2.5L duratech engine produces roughly 175hp and 175ft-lbs of torque. There were a couple of other engine options for the Fusion as I read in US News.

A 2.5-liter four-cylinder engine that makes 175 horsepower is standard on the 2015 Ford Fusion. The 2014 Fusion’s turbocharged 1.6-liter four-cylinder engine and manual transmission are not offered for 2015. However, the turbocharged 1.5-liter four carries over for 2015, which produces 181 horsepower. The most powerful engine in the Fusion lineup is a turbo 2.0-liter four-cylinder that makes 231 horsepower (240 with premium gas).

The turbo engines are the Ecoboost. The 2.0L version should fit the Mazda3.

From Wikipedia:
1.5L turbo - 181hp, 185ft-lbs (2014 - present)
1.6L turbo - 179hp, 184ft-lbs (2013)
2.0L turbo - 240hp, 270ft-lbs (2013 - present)

EcoBoost is a series of turbocharged, direct-injection gasoline engines produced by Ford and originally co-developed by German company FEV Engineering and Mazda. The Ecoboost 2L and 2.3L are Ford turbocharged derivatives of the Mazda L engine.
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Here is a 2016 Ford Fusion ecoboost (2.0L) with 37k miles on it for $750. I *think* has the turbo on it, but it is difficult to tell for sure. I had to look up turbos for the ecoboost and it is quite small, and funky looking. A refurbed turbo goes for less than $600, but I'd make sure to find a low-mileage engine with a turbo on it. Of course, the turbo is considered an accessory and so they won't guarantee it, but low miles = most likely a working turbocharger.


Here is a link to what the turbocharger looks like.

Edit: there is no turbocharger on this engine. The turbo is mounted on the exhaust manifold side. Engines with turbos in place are commanding $1100 - $1300 from what I can see.
Some vehicle information on the 2.0L Ecoboost as well as the newer 2.3L Ecoboost.

2011-15 Explorer - 2.0L
2011-14 Edge - 2.0L
2013-15 Escape - 2.0L
2013-16 Fusion - 2.0L
2012 Focus ST - 2.0L (this one had 252hp)

2016-19 Explorer - 2.3L (280hp, 310ft-lbs)
2015-19 Mustang - 2.3L (310hp, 320-350ft-lbs)
2016-18 Focus RS - 2.3L (350hp, 350ft-lbs)
2019 Focus ST - 2.3L (276hp, 310ft-lbs)

The 2.3L version of the EcoBoost engine debuted in the 2015 Lincoln MKC crossover and has been implemented in many Ford and Lincoln vehicles with various outputs.

The 2.3 L EcoBoost engine is produced with the 2.0 L EcoBoost at the Valencia Engine Plant in Valencia, Spain. In March 2015 Ford announced the official production start of the all-new twin-scroll 2.0-liter and 2.3-liter EcoBoost engines for North America at its Cleveland Engine Plant in Ohio.

The 2.0L twin-scroll Ecoboost is found in the Edge, Escape, and Fusion after the dates I listed above for the 2.0L Ecoboost. I don't know about Mazda compatibility with this newer engine.
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The turbo is mounted on the exhaust manifold side. Engines with turbos in place are commanding $1100 - $1300 from what I can see.
Here are three pictures to show what the turbo looks like on an off the engine. The first picture is a Reman Ecoboost engine showing the turbo with heatshield in place. It's on the exhaust manifold side of the engine. The 2nd pic shows an engine with the turbo removed; there is a single exhaust port (with red plug installed) instead of the normal four separate ports. The 3rd pic is of a turbo facing the direction as it would be bolted to the engine.

Any ideas as to how the Mazda exhaust would mate up with the Ecoboost engine? Another issue I see is with the engine mount. The top of the timing cover has three threaded rods instead of just two. That would mean a non-Mazda motor mount situation.


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Some other random stuff about the Ecoboost engine.

While the 2.0 Ford EcoBoost engine and its later 2.3 variant share a cylinder block with the L3-VDT and are derived from the Mazda L architecture, little else is shared between the EcoBoost and L3-VDT and they should not be confused with one another. The EcoBoost engines have different turbochargers, Ford-designed heads, different direct injection systems along with featuring Ford's Ti-VCT variable valve timing system instead of Mazda's S-VT.

Mazda LF (2.0L) engine weight - 392lbs (Mazda 2.0L LF-DE/LF-VE Engine specs, problems, reliability, oil, Mazda3, MX-5)
Mazda L3 (2.3L) engine weight - 395lbs (Mazda MZR/3L-VE 2.3L Engine specs, problems, reliability, oil, Mazda 6, Mazda 3, B2300)
Ford Ecoboost (2.0L) engine weight - 300lbs (I've seen 283lbs listed as well)

The general recommendation from forum members is to NOT put a 260+hp MazdaSpeed3 engine into a normal Mazda3 with people citing drivetrain, suspension, brakes, carpeting (I made that one up) as various reasons that the higher hp will break the daily commuter. So, the 300hp Ecoboost 2.3L should not be considered. Is the 240hp Ecoboost 2.0L a suitable choice?
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Here is a list of potential pitfalls related to the 2.0L Ecoboost engine that must be overcome in order to make this swap possible in an '06-'09 Gen1 Mazda3. I will edit this list as people come up with additional legit hurdles and possible solutions.

1. Ti-VCT vs. S-VCT. The Ecoboost uses Twin Independent Variable Camshaft Timing while the MZR uses Sequential Valve Timing. There are two camshaft position sensors with the Ecoboost while only one with the MZR. See picture. Solution requires: Ford wiring harness...others?

2. Exhaust manifold. The Ecoboost has a special manifold (of sorts) for combining 4 exhaust ports into 1 before routing the exhaust through the turbo. The resulting exhaust would have to be similar to any Ford vehicle using an Ecoboost engine. Solution requires: Custom pipe to extend from turbo to Mazda exhaust. Probably would need to include the O2 sensor.

3. Engine management. In all likelihood the Mazda ECU is incompatible with the Ecoboost engine. This isn't a show-stopper since there are various websites where professionals and enthusiasts have put Ecoboost engines into a variety of older cars (one example is 'project ugly horse' which uses an older mustang). Solution requires: M-6017-20T control pack or similar, about $1600. https://performanceparts.ford.com/part/M-6017-20T

4. Motor mounts. Two studs for the Mazda PSMM (part of the timing cover) and three studs for the Ford PSMM (mounting base is bolted on to the timing cover). See picture. Solution requires: Adapting Ford PSMM to the Mazda frame, or customizing a mount for the Mazda PSMM to the Ford timing cover.

4. We can talk about small stuff like where to mount the intercooler? Which oil pan to use? Do you need to find a new home for the A/C compressor? And on and on. But I find those to be small things that require ingenuity. Large things require spending money, but it's money that may be well worth it for a killer project.


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Ford head gaskets do have a tendency to go...well..boom...
My daughter's Mazda head gasket went boom. That's why she now has a Ford Duratech engine in her Mazda3.

Plus, if someone is going to do an engine swap they can replace as many gaskets as they want before putting in the new engine.
For some reason I always find myself reading a Miata forum after a while...hmmmm.

In 2016, someone wanted to do a 2.0L EB engine into a Locost 7 (a poor man's Lotus 7). Another poster was playing devil's advocate and said for the same money you could get more power out a 2.5L Duratech engine and not have to deal with as many hassles. That said, the hp would have to be increased from ~175 to 240 in order to match a 2.0L EB.

As the usual natural aspiration devil's advocate, here I go:

2.5 Hybrid Engine (12.3:1 CR): $700
Crane/Crower/Cat cams and MZR-DISI valve springs: $400-500
Jenvey 50 mm ITBs: $880
S2000 OEM 4-2-1 Header+Massive Duratec flange: $100
Microsquirt: $300
ARP rod bolts for extra insurance: $75

For less than $2500, you can make the same or more power than a stock turbo 2.0 ecoboost from an NA 2.5 Duratec and without the frustration of direct injection, VVT, and an OEM ECU. Put the same money for a turbo upgrade into forged rods, pistons, and a $180 2.3 EB forged crank for the 2.5 and you're looking at a naturally aspirated monster worthy of installation in a Seven.
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More info on the 2.5L Hybrid engine. Also, see https://forum.miata.net/vb/showthread.php?t=621275

The 2.5 hybrid engine is any 09+ Ford 2.5 4-cylinder in a hybrid application (Fusion, Escape, Mariner, Milan, some Lincolns?). As far as I can tell, it is identical to the normal Mazda L5 except for nearly flat top pistons for 12.3:1 static compression ratio and a retarded intake cam for Atkinson cycle operation. The late intake valve closing timing allows the engine to have a low dynamic compression ratio compared to its expansion ratio on the power stroke, yielding an engine with less torque but increased efficiency and the ability to run low octane gasoline. If you plan on adding serious cams to a 2.5 without opening the bottom end, it is worth spending a few more bucks on the high compression factory engine. If you plan to upgrade the rotating assembly, the hybrid engine isn't worth the extra money and you should start with a $3-400 standard 2.5.

These are the 12.3:1 CR Atkinson cycle 2.5's that just need cams (and requisite springs) to make power:
Mercury Milan 2010-2011 gasoline, 2.5L, Hybrid, (VIN 3, 8th digit)
Mercury Mariner 2009-2011 gasoline, Hybrid (2.5L, VIN 3, 8th digit)
Mazda Tribute 2009-2009 gasoline, Hybrid (2.5L, VIN 3, 8th digit)
Ford Fusion 2010-2012 gasoline, 2.5L, VIN 3 (8th digit, Hybrid)
Lincoln MKZ 2011-2012 gasoline, 2.5L (Hybrid), (VIN 3, 8th digit)
Ford Escape 2009-2012 gasoline, 2.5L, VIN 3 (8th digit, Hybrid)

The low compression 2.5 everyone else is using is VIN A, 8th digit and it's great for people running pump gas and small cams. The hybrid engine could be great for guys running E85 or longer duration cams with pump gas but not stratospheric revs. For high (beyond 75-7800 rpm) revs and high valve lift, I think it makes sense to build the cheaper low compression 2.5 with the rotating assembly of your choice.
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Performance parts for Gen1 Mazda 3 from SRMotorsports. This could be used when transforming a 2.5L Duratec to a Mazda engine for use on the Mazda 3.

Stock pulleys weigh 8.2 lbs.....our SR power pulleys only weigh 2.1 lbs !
Dyno sheet with our NEW Underdrive Power Pulleys on it.
The Project Mazda3 picked up 9+ Horsepower with them. Fits 2004-2009 Mazda3.

On sale for $299, down from $749. Nice colors. I don't know if the price-to-power ratio is very good, but if you got some money and want to add some bling to your engine build project, then go for it.
Mazda3 and Mazdaspeed3 Underdrive Power Pulley Parts. Mazdaspeed 3 and Mazda 3 Performance Parts.


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This is a post by Moto-Mike from Moto East. This is getting closer to what I'm looking for as far as describing what is needed to get 200+ hp out of the 2.5L Duratec engine.


The 2.5 has an NA profile sort of like this:

165-170 whp stock, but lots of torque. This is with I/H/E.

Add cams, either ours, kelford, or tomei. We take OEM cams and grind them to our custom profile. Works great and race tested with no issues. Kelford is out of new zealand and takes a while to import and for the cost isn't necessarily any better IMO so we don't currently offer them (but this may change). Tomei stopped production and theirs appears to be a grind as well as they include lash caps like we do.

That puts you at about 180-185 whp. After that you have two paths to 200hp. One is high compression and leave the rest as is, the other is do the rest but leave the motor alone. Both will net about 200-205 whp but with no loss of torque. We make the stage IV cams which will do that, or you can pay a few grand for the world challenge cam package which offers similar results.

Next up is doing all three. We got 230's HP on that. That's the WC spec pistons, forged rods, intake manifold, and our large primary header.

That's the highest NA 2.5 I'm aware of...though I wouldn't be surprised if the british have an ace or two up their sleeve.

Driveability? Not half bad at all. Idles around 1000, great torque curve, and runs on pump gas (albeit 5-10hp less)!
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Good-win racing has a lot of information on various headers (short, long, 4-1, 4-2-1) and a variety of pipe sizes (from 1.6" to 2.0") they experimented with in Project Blue, a racing Miata. Obviously with the Miata being a RWD car and the Mazda3 being a FWD car, the headers are different because the engine is mounted 90 degrees off for FWD. While there are plenty of headers for Miatas, there doesn't seem to be as many for the Mazda3. I'm not talking about "race only" applications. I don't want to build a track car. I want a better performing daily driver, so I need a street legal header.

Street legal headers are expensive because they will contain a single cat (CA has a double-cat requirement, so out of luck there). The best one I can see is from MagnaFlow.
$655 for a Gen1 sedan, $712 for a Gen1 hatch.

I've read positive things about OBX headers, but they aren't street legal because of the cat delete. $526.

Pair the MagnaFlow header with an exhaust from Good-win racing for $539 and the output side is well taken care of.
71202 for sedan, 71201 for hatch

The 2.5L head has really good flow compared to the 2.3L head. The racing teams recommend a Moto-East stage 1.5 cam for DD and stage 4 cam for track/racing. All you need is a better intake.
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