Have we talked about Miata Ecotec swaps?

So a while back a quite clean '94 M Edition Miata fell into my lap for a song. It's pretty complete... the only things missing are the engine, transmission, and driveshaft. I couldn't take on a project car so I suckered my dad into buying it. 

Now we're trying to figure out what to do with it. 

The GM Ecotec swap sounds very attractive. 170-200 hp and similar tq from a cheap, plentiful, reliable, basically stock, n/a 4cyl without adding weight? Too good to be true? 

Anyone have experience with this swap? Things to look out for?

https://www.ecotecmiata.ca/

Knowing nothing about either drivetrain, I'd say physical size of both the engine and transmission come first - do they fit?

Where does the stick end up?

Miatas use a drivetrain torque brace... what's the plan there? It's a big deal and not something that should be left out

Next would be how hard it is to interface to the existing electrical system.

Other than that, you've walked into the Church of Cars and ask permission to do an engine swap? Proceed.

kb58 said:

Knowing nothing about either drivetrain, I'd say physical size of both the engine and transmission come first - do they fit?

Where does the stick shifter end up?

Miata's use a drivetrain torque brace... what will you deal with that? It's a big deal and not something that should be left out

Next would be how hard it is to interface to the existing electrical system.

Other than that, you've walked into the Church of Cars and ask permission to do an engine swap? Proceed.

It fits . The swap kit available from ecotecmiata.ca utilizes the factory Miata transmission and subframe, so those are non-issues. 

Mostly looking for first hand experience with this setup. Does it end up rattling your teeth out, does X part suck and fail immediately, is the whole thing a waste of time and it'll never run, etc. 

In reply to thestig99 :

I'm pretty sure kyallroad had one for a little while, maybe he'll be able to chime in with his experience

Another thing is... will it be "enough?" I mean, for the amount of work involved, will the OP be happy with it, or quickly readjust and want more? I guess my point is that if a power plant swap is going to be done, the OP should pick a point on the power-versus-price curve where he'll be happy for a long time. Is that point an Ecotec, or possibly something further up the curve?

Yes we are enablers and not it's not our money :)

Is any engine swap ever "enough"?  

I think a solid, reliable, 200hp/200ft-lb in an NA Miata would be a great place to be in the real world. Especially when paired with the apparent cost and simplicity of this swap. FWIW, I've owned a basically stock power NA for nearly 7 years now.

I've got an NB with a Jackson supercharger. It should be around 180ish with similar torque. It's fun, but it's not V8 fun. It still behaves like a Miata, but with noticeably more poke. Engine choice will depend on what you want. A peppy Miata? A junior Cobra? For me a reliable 200 HP and extra torque would be a fun car for back road cruising. That's what my current Miata is for.

I mean with LS drivetrains being as cheap as they are now. Why not just go 5.3? it will be similar amounts of work anyway.

I think the answer is Honda's J-Series. 

http://www.superfastmiatas.com/JV6%20Miata%20Kit.html

In reply to MrChaos :

Doesn't that really add a lot more expense in terms of needing to upgrade the transmission, rear end, and I think, axles?

The engine may not be a lot more expensive, but the supporting cast for that kind of power is what punts it well up the scale, or at least that's my what-I-heard-on-the-Internets understanding...

Ransom said:

In reply to MrChaos :

Doesn't that really add a lot more expense in terms of needing to upgrade the transmission, rear end, and I think, axles?

The engine may not be a lot more expensive, but the supporting cast for that kind of power is what punts it well up the scale, or at least that's my what-I-heard-on-the-Internets understanding...

This. We talked about the 5.3 LS he has sitting on the garage floor, but the complication and cost of mounting that and putting a driveline behind it puts it out of the realistic realm. Complete running Ecotec donor cars are plentiful in hte $500 range. 

Honda J was discussed as well and looks great. I've ridden in a J swapped NB on track and its a good time. It does appear to be more costly than the Ecotec, though. 

This has come up a number of times and it always goes in the same direction.

There are a many good swap options but nothing is even close to the bang for buck like an Eco swap. I've driven them and the extra torque makes it feel like a completely different car. I know he's sold a lot of kits, done a lot of swaps and sells them as fast as he can build them. They also have a lot of race hours on their own cars so they pretty much have it figured out. The cars are very fast on the track.

Disclosure: Matt is a good friend of mine.

Im curious about this engine as a possibility for my ae86. How do they do in endurance race scenarios?

If you're using the car for autocross, what class do you get into when the engine is from another manufacturer?

I have a hard time justifying "bang for the buck" when the adaptor plate alone is $900.

For under $900, you can get an NC 5 speed, which is an NA/NB transmission.  Swap the tailhousings over and you can put a Duratec in.  (I am still unclear on the possibility of a speedo drive on the NC output shaft, however)

The only real advantage I see to the Ecotec is that GM engine controllers are much happier to play off by themselves than Fords tend to be.  Not having dealt with either specific controller, I could be way off base.  I do understand that the LNF's PCM doesn't play happily by itself,  but the naturally aspirated ones should be just fine.  Ford, on the other hand, has VVT on the Duratecs worth thinking about, and this generally means you want the Ford computer so that you don't have to do as much wheel-reinventing.

If I was going to swap a Miata, I wouldn’t consider anything other than a K20/24. 

In reply to AnthonyGS :

The Ecotec power recipe book that GM published was mostly geared towards high boost drag racers, but there was a 300HP naturally aspirated build that looked pretty basic.

Most of the parts are probably not available (like those awesome 930 axle to 4T65 adaptor stubs) but the information is pretty good.  There was also info on how to wire up switches to control a 4T40 or 4T60 transmission manually.

I'd say the pros of the Ecotec are its an affordable, well established, reasonably installer friendly, documented and reliable setup. The K series swap might be better, but it's more expensive. I have to imagine that matters to most owners of a car with a typical value of a few thousand dollars.

Ecotec vs. Duratec: The Ecotec LE5 2.4L also has VVT. The LE5 had some trickle down tech in its development from the 2.0L turbo LNF. Supposedly the LNF turbo and exhaust manifold can bolt right on (granted at that level suppoidly you're pushing the limits of other parts of the Miata drivetrain). I'm not sure what the upside is of the Duratec setup; more work? less turnkey?

Interesting read here: https://drivermod.ca/2018/04/19/two-years-later-the-ecotec-miata-swap-reviewed/

Yep.  Had one for about a month.  I didn’t build it but I will say it was an incredibly simple/straightforward build.  The motor fits perfectly, being aluminum it was actually a bit lighter than stock.  LE5 GM mill makes far more torques than the 1.8 it replaced.  

Unfortunately some little things kept it from being stellar.  The PO had deleted the balance shaft because “racecar” and combined with the near rigid motor mounts it buzzed hard at under 4,000 rpm.  Factory 5 speed and 4.3 torsen combined for excellent acceleration but a very short legged feel and 2nd topped out at 52 mph.  In a drag race it was at least a match for a MSM but the gearing was equally bad at autocross.  

Mine didn’t have AC or cruise control which seemed like things I wanted in a dd/ autocross toy.  I’d guess they can be added (he said something about a BMW compressor) and the GM computer apparently is an easy enough hack for people with HP Tuning capability/credits.

The LNF would be a lot more interesting, although it would call for a bit of packaging thought to place the turbo, intercooler etc.

Easy to get into the 4-500 bhp range if you like, and have the driveline to take it.  And it actually gets better gas mileage than the LE5 when your foot in't pushed to the firewall......

Looking at that swap, I'd really like to see a Duratec swap into an NB.  For more personal reasons that logical ones.  But I really like the Duratec motor a lot.

The 2.0 Ecotec fits in a 24"x24"x24" cube and will easily make 325/325 on pump gas with a tune or nearly 400/400 at the wheels if you get E85 or 100 octane gas in it. The LNF is the most understood Ecotec and I would recommend that over the later LHU or LTG (even though I have an LHU). Quick Time makes a bellhousing to fit a variety of transmissions, CBD makes road race oil pan and ZZP has every other go-fast part you could want. I love my Ecotec except mine uses the later E39A ECM and tuners are still figuring it out.

Knurled. said:

I have a hard time justifying "bang for the buck" when the adaptor plate alone is $900.

Prices have risen since I last looked at it so it's not as cheap as I remember, but part of the bang consideration is that this really is a plug and play type swap. There is no guesswork, which you can't say about the Duratec, so I don't think it's really a reasonable comparison.

I know a lot of people don't like the idea of a GM motor in a Mazda. I get that because I would never put a Ford motor in one of my GM cars,  and though I don't really know about the Duratec it does not look to me to be a better swap candidate than the Eco, other than staying in the family.

Fitzauto said:

Im curious about this engine as a possibility for my ae86. How do they do in endurance race scenarios?

VERY well.  Usually trans or rearend issues are the suspect bits.

I have raced against a number of them in Champcar and have not heard of any engine related issues.

I don't think any have won overall yet, but they will.

I was researching swap options heavily when my motor blew last year, I was really leaning towards the ecotec swap because it ticked a lot of the boxes (including an option to keep A/C with the BMW compressor), but ultimately I realized that it wasn't the bargain I'd hoped it be.  At the end of the day, as good as the 2.2 is it only makes 140-150hp, and it just doesn't make power with bolt-ons and a tune like a K-series does.  The "200hp" that owners like to tout never seemed to materialize except in high $$$ race builds.  The more realistic I was about how much money it'd ultimately nickle-and-dime me for, and the sort of power I'd actually get, the less interested I got.  I think it makes a ton of sense for an endurance racer, but not so much for a street car.