Tekgnome

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Anonymous D

Check out the monster Miata kit. It'll give you a good idea of what you need.

And it's not so much the Explorer / Mountaneer block as it is he heads and intake.

I bought a wrecked mustang so Id get a bunch of the stuff I needed at once. If its an auto you will need a new computer or a chip though.

tbone heller

Get a conversion manual from Martin at Monster Miata so you can see what all is involved in the swap and what parts you will need.

Tekgnome

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Anonymous D

I paid $550 for the car. Its a '94, so I got the SN95 setup, which is a little different than the Monster Miata manual. But I'm still using the manual. The front accessories are tucked in a little better, the shifter lines up better, and the CCRM controls all the fan functions. Those were the reasons I went with the SN95 over the Fox Mustang.

And that book is like $70, but it's totally worth it.

Tekgnome

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MRM331

Honestly an engine from an Explorer/Mountaineer is going to get you more of what you want if you are going to go with shorter front accessories and what the better iron GT40 heads and the Cobra-internal Explorer intake. If you are going with an aftermarket head and intake combination just start from a reman short block. If you also want to upgrade the engine's internals (needed if you want more than 300 or so at the crank) just find a HO roller block with mains on craigslist and start from there.

On my last build the only actual Mustang-only part was the alternator bracket and bell housing.

You only need to chip the auto mustang computer if its an SN95. Fox A9L's can be used interchangeably since they did not control the slushboxes.

++++ on picking up Martin's manual first. He'll deduct what you pay for it off the price of the kit once you order one.

Good luck,
-Jason

Tekgnome

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MRM331

I made one up a few cars back that made a nice 225 rwhp. Here's what I did:

-Stock Mustang/Explorer reman bottom end - bored .03 over so it came out as a 306. Normal compression

-Iron GT40 (not GT40p) heads off an Explorer with upgraded springs. The springs were a good idea but not really needed with the GT40's unless you want to run a non-stock cam. The GT40p's springs are total crap.

-Explorer intake manifold, 65mm throttle and 72 mm mass air meter. The flange on the meter had to be modified to work with a cone filter and the throttle had to be worked a little to allow the cable to pull from the opposite direction.

-19lb injectors from the Explorer.

-A9L from a automatic 1991 Mustang 5.0

-1992 Mustang cam from eBay

-3.27 Limited Slip factory Thunderbird rear and standard 5.0 Mustang WC T5

All the above got me a very nice package in a 1990 Miata that could hold its own on a road course (normal Miata suspension upgrades - coil overs, sways, etc) but also got 25 mpg's and was very easy to live with as a daily driver.

The formula above could have been possibly pushed an extra 25 rwhp by swapping in a E303 or custom cam, playing with the stock tune a bit, etc. It was by far the easiest to drive, and thus the most daily enjoyable, V8 Miata out of the 4 I built and 10 or so I've worked on. It also came in under $14K total when finished.

Today I'd look more toward the two V6 options for a similar build. If I was only looking for 225 to 250 hp I think my go to would be the Honda JV6 swap. Because it uses the Miata driveline it can be done for literally what a turbo would cost to do. It will not sound like a V8, but with the right slim diameter true dual exhaust set up it could sound very much not like a minivan.

I'm shooting for the 300 rwhp level this time and going with LFX V6 kit to do so. To build one of these is still a bit more than the JV6 but comparable to what I spent building the 1990 above.

There is still a place for the Ford V8 builds and I think that is the space right under the LSx builds where the builder is capable of having the engine built and still wants to beat a comparable LSx build by $5K to $10K. While the kit is easier to work with the engine can not just be dropped in, it needs to be built.

If you are set on the V8 I'd go with a pull out low mile Explorer/Mountaineer with GT40 (not GT40p) heads and intake. Swap in a better cam and the engine is done. Pull a A9L and harness from a Fox Mustang and swap some connectors over or pull a SN95 ecu and harness. You'll need a Bell housing and block plate from eBay or craigslist and a Mustang oil pickup. If you are having Martin modify your pan he'll need a new one to weld on anyhow so the Explorer's "wrong" pan will not be an issue. The existing short Explorer accessories may fit fine, if they do not you may need to pick up Mustang or Thunderbird ones. I think I've seen Explorer ones used in the past though. You'll also need a Mustang distributor since the Explorer has coil packs. As this is something you'd likely have to replace in a donor Mustang anyhow its not that big of a deal.

Hope that helps,

-Jason

Tekgnome

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MRM331

Here you go:

JV6 Miata Kit SuperFastMi



Everything is Miata from the adapter plate back and the engine forward. The kit is a little steep for what you get (IMHO) but the fact that you can keep everything else sort of cancels it out. I'm leaning toward the LFX kit as I want to push it beyond the 300 rwhp mark and maybe even bolt a supercharger on it at some point (400+RWHP).

Here's the LFX kit:

https://v8roadsters.com/product/lfx-mounting-kit/





-Jason

Tekgnome

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topdownfun

Another interesting benefit of the SN95 is that the stock intake fits under the Miata hood with no cutting of webbing. As to the shifter location, though the SN95 has a 5/8" longer input shaft and corresponding bell housing which would put the shifter closer to the center of the stock location, you might have a problem with the location of the clutch slave cylinder, don't know for sure but it's tight in there. Using a foxbody bell housing makes it easy to use the better T-5z (no need to swap out the input shaft) if the need/desire/opportunity were to arise.

TM

MRM331

I've used Car-Part.com to figure out prices on stuff like this. Keep in mind that "sitting in some guy's garage" is not the same as an engine from a real salvage yard. Offer him 75% or less of what the yards are getting.

I actually looked extensively into both the JV6 and the LFX in deciding which way to go with my next build. The adapter plate will take a whole list of J engines, not just the two he lists. The best that will fit with the kit with no adaptation is the J35a3 from a 2001-2002 MDX. This engine has the same block as the j32a1 but with a longer stroke forged crank to get you 3.5 liters as opposed to the 3.2 of the j32. The heads and cams are the same. The j32a3 from a 2004-2008 TL is probably the nicest engine that will fit out of the box but you'll need to deal with the integrated exhaust manifolds (not a problem but not tried before). The best would be a Frankenstein J using an overbored block of a J32a3, the internals of a J37a1 (2007-13 MDX) and the intake of a J37a4 (2009-14 TL SH-AWD). You'd end up with 300hp and 275 foot pounds of torque. This was my plan until I realized that 270 pounds of torque would require adding a Miata 6-speed and a Getrag rear which put the build within $500 of the LFX build. The LFX gets a trans that can take the power, constant veritable timing as opposed to intake-only, off/on VTEC, an easier to deal with engine management system, 30 more HP and the possibility of a donor engine with under 5000 miles from 2015. Exhaust routing is also much easier if you want to go with true duals due to the elimination of the PPF.

DO NOT use a j35a1. Not only did it start its life in a miserable minivan but also has a low strength block with fiber reinforced polymer (plastic) cylinder liners and low compression. It also has a cast crank, not forged. Stay away.

Here's some J info:
https://en.wikipedia.org/wiki/Honda_J_engine

-Jason