We’ve been keeping a close eye on V-8 Miata swaps [click for large gallery of images], with an eye towards possibly building one ourselves. That means very closely looking over Miata V-8 swaps at car shows, as well as reading all the literature and examples on websites we can find. Here’s an interesting post over on LS1Tech.com (active thread this week), with images of a LS3 swap performed by Flying Miata themselves using their extensive array of swap parts and kits. The car is now in Canada, being tuned by Champion Motors.
The dyno numbers are very good:
But what interests us most is how clean the swap is. And particularly the air intake:
Notice the Corvette-derived air intake tube, feeding from a filter mounted ahead of the radiator. Most V-8 Miata swaps end up with an air filter directly behind the radiator or off to one side due to space constraints under the hood - which would feed the engine hot air from the radiator or the headers. Very inefficient, and a tuning and drivability issue. Here are two examples.
The following Ford swap (unusually, a 94-95 Mustang/T-Bird swap, instead of the much more common 86-93 “T”-manifold and engine swap as in the original Monster Miata) is typical of Ford swaps in that the air filter ends up behind the headlamp to the left. Presumably it can pick up cold air here and it isn’t terrible. But it’s still a problem when moving slow, and it will be a problem in wet weather. The filter would be full of water in a rain storm. The very appealing V-8 Miata with the Toyota 1UZ-FE swap we encountered also had the same layout.
And here’s the worst location: right behind the radiator and too close to the right exhaust header. In real-world use, when moving slowly thru traffic or stopped, this engine will be breathing very hot air.
And real-world is our main interest here for a V-8 Miata swap. While we wouldn’t be driving it very often in daily use, we would be driving it on back-country drives here in Texas. These types of drives are tough on the car. An air filter very much lower than the bumper level will pick up water from the multiple water crossings we encounter on some of our favorite routes, and the typically low exhaust systems forced by Miata space constraints would be constantly dragging when on rough roads where suspension travel and ground clearance is crucial. Those are the two issues that must be resolved for us before going further. The adapted Corvette intake tube solves the first issue. Now we are going to pay more attention to exhaust systems as we encounter further examples.
In our ongoing search for unique engine swaps, here’s one we almost walked right past. At the November 1st Cobb Tuning First Thursday event in Austin Texas, we spotted a very clean early Miata and didn’t pay it any particular attention. After all, at Cobb Tuning, the emphasis is on turbocharged cars with considerably enhanced output. What could a Miata offer to the attendees?
Looking closely, we were surprised to see a V-8 swap – but not the usual Ford or Chevy engines this time. Meet the Toyota 1UZ-FE engine swap: an all aluminum 4-liter DOHC V-8 used in Toyota and Lexus luxury cars from 1989 thru 2002. And note how well it fits: short, compact, room for headers, and the hood is at stock height. With an oversquare (big bore, short stroke) design, this engine revs well and already has a well-deserved reputation of reliability as delivered by the factory (which in this case, certainly did not foresee this use of their engine).
Unfortunately, the owner was nowhere to be found, so we don’t have any details as to the transmission, and we didn’t see any cutting, but the rest of the swap was terrifically clean. Clearly the car was stripped down to the bone, and painted inside and out. Overall this is probably the cleanest and most professional V-8 Miata swap we’ve seen, and certainly the most interesting. In our humble opinion, V-8 Miatas are becoming a bit common these days, when powered by Ford or Chevy. It’s time to put modern engines into these cars, and the Toyota UZ engine appears to be the perfect choice.
Use the category tags below to follow our series covering engines swaps, or our series specific to V-8 Miatas.
We’ve seen a lot of different V-8 engines swaps into Miatas over the past few years and covered many of them in posts here. We’ve seen neat swaps performed by individual builders, but we’ve also seen poorly executed swaps and outright hack jobs. Last night at the Cobb Tuning First Thursday car show in Austin TX, we saw the cleanest V-8 Miata that we’ve encountered to date. Built by Flyin’ Miata themselves – note the brass badge on the radiator support. As close to “factory” as it gets, and it looks it.
But here’s one more feature of this particular swap that we really liked. Note the original Corvette intake tract. Besides being neat and efficient, it also keeps the air intake away from the hot engine compartment. Which is a major problem with all the other Miata swaps we’ve seen, where the open air filter is usually just behind a headlamp, just inches away from the exhaust manifold. And sometimes behind the shock tower, up against the engine firewall. Not smart: it’s not going to work in hot traffic, and even at speed the engine will still be ingesting extra-hot air. This approach is far better.
We’ve seen many V-8 Miata engine swaps, as well as I-4 and V-6 swaps. This one is the king of them all: 2 (two!) V-8 engines, inline, and slaved together. You might call it a V-16, although technically it’s not.
In the video you’ll note that, unfortunately, this is one Miata that is not suited to the autocross course :-)
The V-16 Miata was built by one Tony Hair, who used two relatively cheap “Chevy 350″ engines. Why would anybody build such a thing? Answer: just ’cause. In the world of engine swaps, the question “why” is never asked. Once completed, some might call this the “ultimate” Miata. Keep in mind that as soon as something like this is built, somebody, somewhere, is going to start planning something even more outrageous. That is what the engine swap hobby is all about.
The original ”Monster Miata”, detailed in this post: http://www.drivingenthusiast.net/sec-blog/?p=2089, was one of the most significant aftermarket creations for Miata enthusiasts in the 1990s. With a transplanted Ford 302 V-8 engine, a matching transmission and differential, and even a full heavy duty IRS from the Ford Thunderbird in some models, the Monster was the top of the line Miata anywhere in the world. Call it the Sunbeam Tiger for the 90s, or in modified form perhaps even a (Mark II) Shelby Cobra. Shelby Cobra? Why not – the 302 could certainly be built to put out 500 HP and in a 2500 pound car would provide “supercar” performance.
But we’re getting ahead of ourselves because the original Monster Miata company went bust after creating somewhere over 275 cars. Those cars demand a premium today if you can find one. If not, consider building your own because swapping Ford V-8s into Miatas is alive and well and the state-of-the-art is quickly advancing. Swapping Chevy LSx V-8s into Miatas is an even newer solution and may be more attractive since they can cover a wider range of Miatas for emissions compliance.
Including the original Monsters, some claim that there are as many as 1000 V-8 Miatas (Ford and Chevy) in existence today. That seems high, but certainly the number will be reached sooner or later due to the shear number of swap kits, parts, and resources available.
We’ve been thinking about building one ourselves - although not for roadrace track use because the jury is still out as far as pushing a car that was never designed for such torque to extreme torsional limits. It’s been done, and even successfully, but after living thru 30 years of track events we would approach such a thing with great caution. Our thoughts instead revolve around a fun car for back roads driving. We’ve been looking for an engine swap project that would result in a car we could actually live with and this one looks like a great place to start. The Ford 302 swap is a known science, and the current holder of the Monster brand rights has a kit with nearly everything you’d need. There are also at least two companies that make the parts needed to swap a Chevy LSx engine into a Miata, right thru the NB generation (with NC in the works).
Emissions compliance is an important question for much of the country. The laws in most states require an engine swap to use an engine that is of the same year or newer as the car it is going into. 1995 was the last year Ford made a 302 with a manual transmission (95 Mustang), so that engine, transmisison, and processor could be used in any 1995 or earlier Miata – but not a 1996 or up. Fortunately, 1995 and earlier Miatas can be had for 3-5 thousand dollars and even less, depending on condition. For Chevy engine swaps, pulling a donor engine from a current Camaro, G8, or even a last-gen CTS can cover any year of NA or NB Miata.
We’ve encountered several V-8 Miatas in our local Cars and Coffee car shows. If you’re not familiar with Cars and Coffee, check out 3 years of photos of Cars and Coffee events in the Events link at the top of this page. We’ve also seen 2 V-8 RX-7s in these events, and that also has our interest. But today we’ll focus on the Miata.
Here’s our first example, an NA Miata with a Chevy engine. If the hood wasn’t open, you couldn’t tell what had been done. The Chevy engine is nearly as low as the stock engine. Note the width of the tires – for this much power you need as much rubber as possible and that’s one big issue with V-8 Miatas. And note the rollbars – a very good idea with this much power on board.
Some V-8 Miatas use dual exhaust, others single. There are several variations of exhaust systems and you will need a very experienced muffler fabrication shop to get it right. For Chevy conversions, there is (very conveniently) a complete aftermarket setup available. Ground clearance is always the single most important consideration.
There are two ways to transplant a Chevy V-8: it either fits in place in the stock (untouched) engine compartment, or to achieve a better weight balance, you can move the engine back a bit further. This requires cutting and welding, along with extensive transmission tunnel widening. The good news is that wiring harness adapters are available which almost make this a plug-in conversion, and at the very least will save you a considerable number of rewiring headaches.
All V-8 Miatas, regardless if engine type, have less than optimal placement of the air filter. You’ll note that in this example, hot air from the exhaust header is going to get into the engine. We keep looking, but we havent’ seen anybody fence off the air filter. And we know from personal experience the negative aspects of sucking in hot air. But nits aside, this is a very professional and clean conversion.
Here’s the air cleaner issue from the other side. Also note the location of the fuel line coming up to the engine… some kits leave it on the left as in stock Miatas, some move it. In either case it has to pass closely by the very hot exhaust system.
Speaking of which, here is the exhaust header on the driver’s side. Very close, but certainly not impossible to work with. And unlike the last-gen Camaro, you can actually replace the plugs without moving the engine. That’s the type of thing that makes this an easy engine swap to live with. Note the clearance notch in the frame just ahead of the air cleaner.
And the interior. The shifter position looks entirely stock, and it’s a T-56 underneath. Looking into this car and not under the hood you’d be hard pressed to detect an engine swap. Start it up, however, and the difference is immediately and loudly apparent. While we were unable to show it, the most popular differential for Chevy engine swaps is a all-aluminum Cadillac CTS differential, with limited slip, and easily available from salvage yards.
Now lets talk Ford.
Our example is not just any 302 swap, it’s a 1995 302 into a like-year Miata. The 1994-1995 302 engines from Mustangs brought with them a different and much more complex electrical system as compared to the system used in the earlier FOX-body Mustangs. A much easier swap would be a 1993 or earlier Miata with a 1993 or earlier Mustang motor. But the builder of our example below wanted a challenge, and created perhaps the only Miata in the country with a 1995 Mustang engine and electrical system.
You’ll immediately recognize the 94/95-style Mustang 302 V-8 from it’s intake manifold. This is an iron block and head engine, with an aluminum intake manifold. This is an older engine that the much Chevy LSx series of engines, so the emissions and wiring systems are a bit more dated (note the distributor instead of a modern coil pack). But at least it clears the hood. Also note the cable-type throttle linkage – a natural fit into the early Miatas.
Hood clearance is not an issue, and the Ford engine is a bit smaller than the Chevy engine. But, the accessories are hung much farther away from the engine and that presents some issues during the build.
The engine is situated as far back against the firewall as possible, but unlike the Chevy swap no cutting is required along the back of the engine compartment. But you will also notice that a much larger cut and weld is required to clear the power steering pump to the far right of the compartment.
Here’s another view of the cut from above. Note the single coil in the stock SN-95 Mustang location.
Looking further back on the passenger side, we see the master cylinder location is stock, and that the headers are a little less of a tight fit than the Chevy conversion. Doubtless with either version there will be some skinned knuckles getting the steering shaft back in.
There is also some special work needed around the air conditioning lines.
Air cleaner placement is much better in this swap. The old Ford-style MAF is a little more complicated with it’s large aluminum housing (versus the Chevy thermoplastic) but the air filter element is away from the hot engine and can better receive much cooler air in this location.
A view of the front with radiator hose placement. Again, unlike the Chevy engine, the Ford water pump sticks out fairly far from the engine, making the entire cooling system a very tight fit.
Some special work is needed up front, including this 90-degree adapter. Like all V-8 Miata swaps, special attention is needed for a specially built radiator, and cooling is an area which needs special focus.
Out back, we have a Ford 7.5″ differential from an MN-12 T-bird, and a custom-built dual-exhaust system. The owner wanted his car to be reasonably quiet, and asked Muffin Muffler in Austin to tackle the job. We’ve had work done by that company ourselves, and their work is always immaculate. Needless to say, it’s an expensive and time-consuming job to create an exhaust system that will provide maximum ground clearance, so it has to be done right.
Special welding is required on the subframe is needed to mount the differential, and of course like all V-8 swaps both the driveshaft and the half-shafts have to be custom built.
Inside the Miata, it looks very nearly stock. The T-5 transmission is in exactly the right place.
Our series of images provides only a very basic overview of the end results of the Ford and Chevy engine swaps. Many more details are available on the web, including forums for discussion and help.
- The new Monster Miata company - the premier source for Ford conversions. Note their 50-page manual, with color pictures and technical diagrams. This is a must for Ford conversion builders, and would certainly be a good idea for Chevy swaps as well.
- Flyin’ Miata- a source for Miata upgrades as well as V-8 conversion kits. Note the detailed stories of several conversions – severla have detailed pictures showing the required frame and tunnel modifications.
- V-8 Roadsters, supplier of extensive conversion parts and kits including heavy duty control arms, frame reinforcement, and big brake kits. Note their discussion board forum – required reading before even considering a swap.
- V-8 Miata blog category: now incorporating our previous Monster Miata posts.
- Miata blog category: not specific to V-8 swaps, but covering all of our “regular 4-cylinder” Miata posts.
- NC Miata cutaway tour:- extensive images of the NC Miata from the press introduction in the summer of 2005. The totally redesigned and much stronger-built NC is just crying for a V-8 conversion. Who will take on the first NC conversion?
We’ve covered many different types of engines swaps into Miatas in the past – V-6 engines (SHO, Mazda), V-8 engines (Ford 4.9 small block), and even a Jaguar V-12. There are several companies building Ford V-8 swap kits for Miatas, but V-6 and V-12 folks are on their own (and so far there is only one V-12 swap – a heroic and very professional effort!).
The arrival of V8 Roadsters LLC makes an engine swap even easier, using a late-model Chevy LSX engine and a Ford 8.8″ differential: http://www.v8roadsters.com
Pictures are below. Their site doesn’t list every last part needed (considerable fabrication is needed – for example a fuel system), and the resulting car won’t have the cachet of an authentic Monster Miata, but the end result looks thorough and should be reasonably reliable.
Speaking of the Monster Miata (in followup to our last post), here’s another view of an authentic Monster with the Ford diff added.
If you are buying a Monster, having this part is the sure way to get both durability and a reasonable RPM. The original Miata or RX-7 gears are in the 4:1 range, and that kind of gearing with the Ford T-5 (whether it’s 3.27 or 2.95 first) is silly.
The diff is available in 7.5 or 8.8″ size, aluminum or iron casing, and with or without a limited slip. The variations occur depending on donor car: SVT Mustang Cobra (IRS), Lincoln Mark-VIII, Cougar, or Thunderbird. BUT – note that only the 7.5″ diff physically fits in this application.
A couple of months ago we wrote up the Monster Miata… it turned out to be one of our most popular posts ever: http://www.drivingenthusiast.net/sec-blog/2007/03/14.html
Here’s a variation on the same theme: a V-8 Miata with a Z3-knockoff body. This car is on eBay right now… follow the link above.
It’s in the same vein as a Monster Miata, but is not an authentic Monster. It was converted in the same way, then a custom one-off Z3-type body was added. The result is as you see below.
The good news is that it appears to be well built (I’d want to look at the fiberglass attachment points). It’s also got the all-important Ford 8.8 IRS differential ( http://www.drivingenthusiast.net/sec-blog/2007/10/20.html#a2237 ), although IMHO the 3.73 gears are ridiculous. The bad news is that the tires are tiny… when they came up with the fiberglass body why didn’t they add some room for appropriate-width tires? And don’t even mention brakes.
In any case, this is unique and would make a fun ride. And while BMW’s original Z3 ugly duckling was originally as slow as a stone, this one certainly is not.
In an earlier post, we covered what a Monster Miata is, how it’s built, and added some thoughts about it’s potential usefulness to a driving enthusiast.
Here’s one last look at the topic, courtesy of a video from TNN:
The “Monster Miata” was the creation and product of Monster Motorsports, a defunct California company. The Monster was a Miata with a Ford 5-liter (actually 4.9) cast-iron block/heads OHV pushrod engine and a Borg-Warner T-5 transmission. The swap was easily accomplished – almost unbelievably the entire engine and transmission fit into the Miata as though it had been designed by Mazda for it (everything fits under the stock hood!). That and some appropriate springs, cooling, and exhaust (restrictive) made up the basic technical package and the cost started at several thousand dollars and the car. The much heavier Ford engine did add about 4 percentage points to the front/rear weight balance – and the car takes a corresponding amount of care to drive in turns.
Somewhere over 275 Monster Miatas were claimed to be built by Monster Motorsports. A couple of hundred unofficial conversions were made by other companies, and kits remain available from them to this day. RX-7 conversions are also possible since much of the chassis is shared.
Unique - but subtle - badging inside and out identified the car to anybody getting close enough to notice. The appearance of the entire car was very stealthy until you started it up: deaf “opponents” wouldn’t know what hit them. Everybody else would get an aural shock.
Like all good things, the “production” conversions were built for several years. Unfortunately, Monster Motorsports as a company has folded – the original website was shut down some time ago.
The Monster was known to be over-geared since the Miata differential gearing was well over 4:1. Even the optional (and much stronger) RX-7 differential posed a problem in this regards. Since the 4.9L Ford was not a high-revving engine, this was an issue for cruising, and the gearing certainly wouldn’t contribute to engine reliability either. Later cars offered the option of a Lincoln Mark VIII aluminum differential with much more appropriate gearing. Even later cars offered the entire MN-12 Thunderbird rear suspension, with very large flares to cover the added width – although only a few were built like this. Some of these cars were labelled as ”Mega Monster” Miatas. Pricing could sky-rocket with options.
Contrary to popular belief, the roughly 225 HP bone-stock Ford engine was the only standard conversion offering, since the car had to meet California emissions regulations. Monster Motorsports also offered some additional power-adders if California aftermarket certification was available for the year it was offered. Of course, given the popularity of the Ford engine, many different power-adding enhancements could be made by owners to take HP up considerably. But the car still had to meet any emissions regulations of wherever it was eventually licensed.
Conversions – aka “swaps” - are an interesting consideration for the enthusiast. California (and most state) laws allow engine conversions if the engine is from the same production year of the recipient car or newer. 4-cam Acura B16 engines are a popular swap in earlier Civics, and even better is a B18 or even an R model engine. There are also some very narrow circumstances where JDM engines that were never certified for the U.S. are certifiable in certain situations – you’ll note a number of people swap engines in their 240SXs for the 2 liter turbo offered in Japan. But by and large conversions are becoming a thing of the past for late model cars; the electronics are becoming too difficult and the emissions certifications are legally and technically impossible. Swaps such as a late-nineties Supra TT engine into an S2000 would be impossible to certify and register in most counties given the trend of emissions laws and testing. But there is another reason to do swaps – and that’s for the technical challenge. That’s one reason we can understand.
Enthusiasts should also consider the value of a classic car. Would an classic 240Z, for example, maintain it’s value as a classic with a Chevy V-8 under the hood? The answer is a resounding “NO!”, and technically the chassis is so dated anyway that the net functional result is debatable. The slightly more modern early Miata has a better chassis, but the functionality is still limited. But there are so many Miatas on the road their value as a classic is small-to-nil. So if a conversion is a must, then “Monster” the Miata!
The following car was offered for sale on eBay . This is a great example and from the ad it appears to be clean. It has the Mark VIII differential and some odd aftermarket headlamps, as well as Ford Motorsports GT-40 intake (we would check to see if it also received the proper matching heads and an appropriate cam). It would be a worthwhile collectible – although we also feel that a close-up inspection would be advised.
This example has an added GT-40 intake. Note my suggestion above. All Monster Miatas used an open air filter – there wasn’t room for anything else. Some sort of partition would have been a good idea so that the engine doesn’t have to suck up hot engine compartment air at idle. Note that the car has AC, but not power steering.
Exhaust routing was a major problem – there was only room for a single exhaust pipe past the cats, although for the sake of appearance it does split at the bumper. The muffler in this example appears to be a flowmaster – which likely wasn’t the original equipment. If this is the case, then the use of the car should be looked into – it may have been used for drag racing. You can also see that the new differential required customer mounts and half-shafts that are different from the original Mark VIII mounting design (the rearmost bushing isn’t used). Many of us are familiar with that differential from it’s later use in 1999-2004 IRS-equipped Mustang Cobras and it would be plenty strong for this engine.
Badging is custom-sewn into the seats (either factory cloth or leather). There is also a nicely made external badge on the top edge of the front bumper. Additional off-the-shelf Ford badging is also available.
The Monster Miata is definitely collectable. An example built by Monster Motorsports would be much preferred. Look for the proper paperwork to guarantee authenticity.
For the performance driving enthusiast, a Monster might work in some autocross classes, although it would be a fully prepared class and the competition would be very tough.
For open track events it’s be at a disadvantage because of the tiny Miata brakes. Some big-brakes kits are avialable and would definitely be needed.
In either case, durability is a open question: will the 4-cylinder chassis hold up to V-8 torque? Certainly the Miata differential, control arms, mounting points, and rear wheel bearings would be potential issues. Straight-lining the car would be a very poor choice.
For the Sunday cruiser, the car would probably be a good alternative to a Sunbeam Tiger. Brakes, transmission, and cooling are probably all superior. The Tiger is far more collectible, and owners should certainly take care to preserve their examples. But the Monster Miata is more easily repairable, and given the very large numbers of Miatas available standard Miata parts are not likely to be an issue. Some re-welding and fabrication may be needed at some point to keep the rear suspension together.
Collectors will find several road tests are available, including two in Road & Track that I remember. Monster Miatas are very rarely for sale, and any potential buyers should look the car over very carefully and also get any and all original literature from the seller.
- Panache: http://www.monstermiata.com/ The original Monster Miata website has been redirected to this one. Parts “kits” are available as is a “big brake” kit.
- Bishop Sales: http://www.bishopsales.com/v8_monster_miata.html - another conversion parts company.
- Enthusiast Scott Keen: http://www.scottkeen.com/miata/megamonster.asp
- Enthusiast info and 1992 model for sale: http://www.highwayone.com/Classifieds/Mazda/01aaai.html
- 1992 model for sale: http://washingtondc.craigslist.org/mld/car/292180781.html
- Mega-Monster Miata article form Australia: http://autospeed.drive.com.au/cms/A_0824/article.html
- Enthsuaist/owner John Burch: http://www.miata.net/motm/2004/burch.html
- 1992 model: http://mywebpages.comcast.net/hartzfeld/92Monster.html