Miata Engines in Other Cars -
For those who don't automatically swap a V-8 into whatever rear wheel drive vehicle they have access to, the Miata drivetrain is a very sensible choice. While the Zetec and Ecotec have many merits, I think there is great value to the fact that the Miata engine and transmission were factory engineered to work together. Does this really make a difference? Probably not too much. But, to me, it feels "right" and it certainly makes things much easier, in my opinion. With the Miata, you buy your drivetrain "ready made" and simply need to install it. To my knowledge, Miata drivetrains have been transplanted into Locost / Caterham / Lotus Seven-style race cars, Datsun Roadsters, MGs of various vintages a Triumph Spitfire and an Austin Healy Sprite. I've put together here a list of the swaps that I have found on the Internet. In the world of print, Grass Roots Motorsports began a series, in June 2007, on doing this transplant into an early-year MGB. They don't seem to have it in their on-line archives; I may scan the story at some point. But, until then... If you know of any such well-documented swaps, please drop me a line & I will post them here. By the way, click on the photos to visit the sites referenced.
	This guy, Bob, has a fabulous website documenting his complete-home-fabbed up-grading of an Austin Healy Sprite. Not only has he swapped in a Miata drivetrain, but he's replaced just about everything else in the car. It runs now & sounds great.
	Not much to see here other than a couple overview shots of the engine bay and some project specs. Here is another photo of a very tidy swap into some other MGA.
	This guy doesn a fine job of documenting the key elements of his Caterham build with photographs and text. His link to the documentation of the work is at the bottom of the intro page. He went with EFI, not carbs, and did some custom work on the transmission (for mounting) and cooling system (for flow). I found a video of his first start here.
	Wade is the first person I know of who has swapped a Miata drivetrain into a Datsun Roadster. His car is a '66, like mine. He did his swap as part of a frame-off restoration. Also, he used a 6-speed transmission, which seems to be narrower than the 5-speed. The photos tell the story.
	Although it doesn't have as many photos as the others, this swap chronicle is very informative. The Spitfire is a tiny, tiny car so it is valuable to see how he got around the problems that the swap posed.
	This site documents the insertion of a Miata 1.8L into a 1973 MGB. While not a methodical how-to, there are good photos of the modified engine and transmission mounts necessary, as well as the alterations to the radiator that they did. To move through the pages, enter the numbers 2-10 between the "miatab" and the "." in the web address.
	I don't know if this counts as a swap, but it's a MG replica kit car that uses the Miata 1.6L engine. There's really no useful technical information on the pages, nor interesting photos of the engine and drivetrain.
	This site is only photos of swapping a Miata engine into a pre-1959 Nash Metropolitan. You get an idea of the transmission tunnel and engine bay mods, though.
	Like the kit car above, this insertion of a Miata engine into an old Morris Minor is more than just a "swap". This fellow built an entire frame to allow himself to use all Miata running gear along with the drivetrain. It looks like quite a project. The website is still being updated occasionally.

Throttle Installation - 
 

	A clean, simple throttle stop that holds the throttle lever in the same position as stock. I could not use the stock stop, however, because it interfered with the coil bracket. Ultimately I will probably modify or reposition the coil bracket, the throttle lever strikes it when the engine lugs and under extreme acceleration.
	The throttle cable was originally the cruise control cable from a late-model Honda. I believe it was a 4th generation Accord. It is, magically, the correct length, has the correct ends and has the clamp bolts at the throttle body end in the right place. All I had to do to modify it is trim about an inch of sheath off the throttle lever end of the cable.
	I don't love the bracket I made for the throttle lever end of the cable. It is the one piece on the car that was designed with a hammer instead of a ruler. But, it works and looks okay if you squint at it. The clamp is stock Roadster.
	Here's a view of how I made the depressed channel in the top of the bracket to hold the cable in place properly.

Gas Tank and Filter Installation - 
 

	I affixed all the mounting nuts for the Honda fuel pump and the ring for the fuel level sender with JB weld. Not sexy, but it gets the job done. Lots of #6 sheet metal screws and a thick layer of fuel-resistant Hylomar gasketing material and the tank is back together.
	The breather tube fitting is a 90-degree elbow: 3/8" hose to 1/4" MNPT.
	The old fuel line outlet is easy to cap. I forget the specs of the fitting, but it's the same as the union fitting along the passenger frame rail, so you can always carry that to the store with you to test fitment.
	I cut strips of a strange plastic felt from a nearby discount fabric store to make the isolating belts for above and below the tank. They should result in the same thickness as the stock felt-like strips.
	Here is a view of the new tank through the access port in the trunk. I would have loved to place the pump farther back, so that it would come out through this hole, but the sump basin was as far back as it would go. I'll never get the fuel level sender out now without dropping the tank. But, at least I can access all the lines and leads from here.
	The fuel outlet on the Honda pump is a 12mm banjo fitting leading to a bizarre steel and rubber hose that is useless in this application. I got a similar hose off a '93 Acura that had a longer steel portion that I cut off before the rubber hose and joined to my 5/16 steel lines with aftermarket 8mm EFI hose.
	The fuel return on the Honda pump is tiny -- 6mm (1/4"). I split the difference by using a 7mm diameter EFI hose between the 6mm fitting and the 8mm line.
	The fuel filter solution is from a 1993 Nissan Altima. It's easy to grab from the salvage yard (for the bracket) as it is mounted on the firewall in the Nissan. I mounted mine in the passenger wheel well. I may end up making a shield/enclosure for it. We'll see.

Fuel Pump Installation -

	I made a few paper templates to figure the smallest area I could cut out and still fit the pump, sump and fuel level sender. I ended up with this rectangle. I drilled out the corners, then cut the panel out with a sabre saw (it did not blow up). Then I drilled out the welds holding on the sender mounting ring and the breather tube.
	The Honda tank is not a simple box, like the Roadster's, so I cut into it with a cold chisel (it did not blow up) to get at the catch can and the complex pump mounting ring (not shown), which I did not use in the end, although most do. If you buy the correct tank, you will not see this catch can, but what follows is how I modified. First I cut off the mounting tabs so that it would sit flat on the bottom of the tank.
	Then, after many fitment tests, I mounted it to one of the baffles with a very large sheet metal screw. A wide fender washer distributes the squeeze of the screw on the plastic wall of the catch can.
	Between the catch can and the baffle is a piece of 1" x 3/4" aluminum channel; it serves as a spacer.
	As mentioned above, the stock Honda pump assembly held the pump too high above the tank bottom for my tastes, so I modified it by cutting the base of the bracket away. Click on the thumb to see before and after.
	With the bracket modified, I could now adjust the height of the pump, and made it so it kisses the bottom of the catch can. The pump is very firmly held by the hose clamp. After this photograph, I replaced the orange rubber with a short section of radiator hose and turned the hose clamp to face down to improve ease of installation.
	If you modify the pump to sit lower as I have, be sure to use in-tank EFI fuel hose for your new, slightly longer hose between the pump and the outlet tubing. Regular EFI hose WILL FAIL, sometimes quite quickly. The hose made by Gates, as a 5/16" side, in 12" lengths. It is Gates #42195185 or #27093 (Napa #H209).

Fuel System Introduction -

When swapping any EFI engine into a Datsun Roadster, or any other car, you have to add a high-pressure fuel pump. The easy way is to mount an external pump, although many report these to be annoyingly loud. I went with the in-tank solution of an OEM Honda pump. This pump works because will fit in the Roadster's relatively shallow tank. Most pump assemblies, such as that from the Miata itself, are quite tall. The installation of the Honda pump has been well-documented by others, such as here. The specific source for this pump, according to my notes, Hondas and Acuras from the second half of the '90s. When I first went to the junk yard, I was in a hurry and (a) did not consult my notes and (b) did not check the pump, or even think very much, before buying the tank. You have to buy the whole tank to get the catch can, so the pump will not be starved during cornering and such. So, since I didn't want to buy another tank, I made due with the wrong catch can and simply used it with the proper pump, which I bought later on. This earlier catch can seems to be bigger than the later one and doesn't fit so well; I had to mount it backwards. I found that, in my opinion, the Honda pump assembly is *too* shallow. With the stock mounting ring, the base of the pump hangs over an inch above the bottom of the tank. The stock Roadster fuel level sender registers "empty" at about 1/4" from the bottom of the tank. So, I removed the ring, but the pump was still high, so I modified its mounting bracket in a manner that is a little kludgy, but should work fine. I went with a no-weld solution because (a) I don't weld and (b) I didn't feel like taking it to a place willing to weld a gas tank only to have them screw it up somehow. There are way too many bits and pieces to get in the right place for me to risk the odds. Again, the end result is not as polished or pretty as I would like, but it is functional, and will be hidden away. It does have the small benefit of being easily disassembled should I need to.

Cooling System Hoses - 

	My engine came with a broken water outlet in the front. I replaced it with an early Miata (i.e. 1.6 liter) outlet, which opens up, not towards the left. To that I mounted a 1st generation Honda thermo housing. The Honda housing needed to have its mount holes bored out slightly. The hose is a portion of lower radiator hose from a 4th gen Honda. Perfect fit, including the jog to one side!
	Down below, I had to create a reducer from the Miata's 31mm (ish) hose to the Honda's 28mm hose. Another 1st generation Honda thermo housing and the thermo housing from a Mazda 323 did the trick. Any front drive Mazda or Kia with the B6 or BP engine will have the same housing.
	The front portion of the lower radiator hose comes from a 5th generation Honda (lower). The rear portion of the hose comes from '93 Protege. Both are cut to fit. The clearance with the frame is much better than it looks from above.
	With the cooling system all buttoned up, I poured 4 quarts of distilled water in and waited for a leak. Boy did I get one: water *pouring* out of the pump housing. Seems the seals in these modern pumps die quickly without water, so the year the engine sat in my yard in Southern California pretty much killed them. Don't let this happen to you! Change your water pump and timing belt at the last possible moment before installation.
	The stock Miata heater line inlet and outlet both jut out towards the driver's side completely parallel to the firewall. To mate with the Roadster heater, I cut the turn off the Miata return tube (not visible here, but shown a few steps below) and assembled an S-shaped hose for the inlet.
	Here is is the S-hose created from the two ends of Goodyear hose #63039. These two bits of hose join the Miata hot water outlet at the back of the block to the Roadster heater inlet pipe, via a Honda heater valve. A custom mounting plate for the control cable is visible as well.
	I'm using the heater valve from an Acura. Just about all Hondas and Acuras from the 90s seem to use this same small valve, with 11/16" fittings. On the Roadster, the cable pushes to open and pulls to close, so I will be installing this valve backwards relative to its stock flow orientation. I've also rotated the lever by 90 degrees.
	I had to modify the valve slightly: I removed the lever and removed the nub that clocked it to a specific face of the square peg. Feel free not to cut as deeply as I clumsily did. I then re-mounted the lever turned 90 degrees from stock, as shown above.
	This plate mounts to the Honda heater valve and holds the control cable in place using a clamp I pulled off an MGB in the salvage yard. Or was it an Opel GT? Anyways, any old car will have a handy screw-down cable clamp.
	This is how the plate looks when mounted to the Honda heater valve.
	Here is a PDF template for the cable clamp plate. If your clamp differs, change the hole and slot at the top accordingly. You'll still find the template handy for locating the offset Honda valve locating pins and screw holes.
	Here is how I cut down the Miata return tube, simply removing the bend (already gone in this photo) and the stock mounting bracket. I made a new bracket and attached it to the tube with JB weld. The tube is 11/16" but a 5/8" heater hose fits on it well enough. Tight is better than loose.
	New bracket for the coolant return tube. Maybe this isn't the best way to do this -- I probably should have made one that clamped. But, this bracket mimics the stock solution, although I substitute JB weld for a real weld.
	Modified coolant return tube completed. The hose is Goodyear #63049, cut down slightly on both ends.
	Here is a close-up of how the bracket mounts to the cut-down Miata coolant return tube.
	I had to cut a hole in the backing plate for the new heater return hose to pass through. The hose doesn't acutally touch the edges, but I want to avoid chaffing. I'll keep an eye on it, and will edge the cut in some sort of rubber trim if there is any rubbing.
	It's hard to see the heater lines all buttoned up, since there's so much going on in that space. I installed a new control cable (from Home Depot, for a lawn mower throttle) and ran it through the firewall in the stock position with a new grommet. No way I'd be able to attach it later.  **PLEASE NOTE** In the stock Miata, water is *always* flowing through the heater. Thus, for the rear of the engine block to cool properly and for the fan to ever turn off after the engine has gotten to temperature, the shut off valve that I detail below CANNOT BE CLOSED. Since it is winter, I don't care. But, I do need to re-plumb the heater valve so that it bypasses into the return line when shut, rather than simply blocking the flow of water.

Cooling System Introduction -
The cooling system for this transplant is assembled mostly from a selection of OEM or aftermarket Honda parts. The radiator is one of those cheap types that you see all over eBay. The fan assembly is from a 5th generation Civic. The heater control valve can be found in just about any Honda or Acura from the 90s. Even two of the three thermostat housings used come from a 1st generation Civic. I actually first installed this radiator and electric fan while still driving the stock engine. It was a slightly tight fit, but I was pleased with the efficiency and quiet of the combo. The greater space created by the Miata engine, which sits farther back, allowed me to clean up my mounting system and create a pretty slick set-up. **PLEASE NOTE** In the stock Miata, water is *always* flowing through the heater. Thus, for the rear of the engine block to cool properly and for the fan to ever turn off after the engine has gotten to temperature, the shut off valve that I detail below CANNOT BE CLOSED. Since it is winter, I don't care. But, I do need to re-plumb the heater valve so that it bypasses into the return line when shut, rather than simply blocking the flow of water.
	This shot shows the radiator and side deflectors installed with the stock Roadster engine. Note the angled cut of the far deflector. The radiator is tipped to keep the bottom away from the tie rod ends and the top away from the water pump nose. With the Miata engine, there is no need to tip the radiator -- plenty of room.
	The aftermarket Honda Del Sol radiator sits in two rubber bushings held by a pair of custom brackets. The brackets mount to existing threaded holes on the cross member; they are cut from 2" x 1/8" steel. The rubber bushings are from the upper radiator mounts of a late-model Daewoo. Plenty of these cars in one of my usual yards, for some reason.
	Here is a closeup of one of the lower radiator brackets. I used these same brackets to mount this radiator when I had the stock Roadster engine in place. The only difference is that I had to use much slimmer bushings (really just rubber grommets) and tip the radiator forward at the top to clear the Datsun water pump pulley.
	Here is a PDF template of my driver's side lower radiator bracket. Although I simply flipped this template over to create the passenger's side bracket, I did find that I had to tweak the bends slightly to account for differences between the two sides of the crossmember. Test fitment with pieces of cardboard or something before cutting the final pieces.
	Here is the upper radiator mounting bracket, with a Daewoo bushing already installed.
	The template for the upper radiator mounting bracket.
	The upper radiator bracket installed. This is not the most comprehensive view, but suffice it to say that the radiator fits very well and square, with a great deal of clearance all around and no cutting of anything (except hoses). It is well-placed relative to the stock air scoop below. I may yet make deflectors for the sides, though, as the Honda radiator does not fill the space.