Let's beat a dead horse: 1.6 vs 1.8 Miata

Well, you shiny happy people are finally getting to me. I am pretty sure I am going to dump the Alfa in the spring for my first Miata. I love the '99-00 cars myself (and fit more comfortably in them, for some reason) but I live in a plug-in emissions state so '96-up isn't an option for me, as I plan to use this as my first Megasquirt project.

'94-95 1.8s seem to be a lot less common than 1.6 cars, and they fetch a premium when they do pop up. My goal is to do a mild N/A bolt-on build this summer and get the MS working, then go turbo over the winter. Other than the crank pulley problems on the super early cars, what would I be losing by going with a 1.6 vs a 1.8? I am coming from an Alfa Spider here so with mild mods either would be a substantial step up in performance, let alone with a turbo - but I seem to recall that the 1.6s have weaker rear ends and a few other unique problems.

The car will be used primarily for HPDEs and summer driving, for what that's worth. I will not be racing competitively or shooting for ridiculous power (200 is more than enough).

Basically, all else being equal, if I had a choice between a nice 1.8 for $5k and a nice 1.6 for $3k, would I be stupid to get the 1.6 and have some money for upgrades?

Why not throw a 1.8 in an earlier Miata? Best of both worlds and the 1.8 engine isn't exactly a bank acount drainer.

DaveEstey wrote: Why not throw a 1.8 in an earlier Miata? Best of both worlds and the 1.8 engine isn't exactly a bank acount drainer.

Because with a perfectly running 1.6 why would I go through the effort? I understand the big-picture advantages, especially going down the turbo path, but saving $2k just to spend $1k and a ton of labor to have a 1.8-swapped 1.6 when I could have just bought a 1.8...why?

It just seems like I can find a LOT more nice cheap 1.6s than 1.8s. I know that the 1.8 is just a better engine, period, but if I'm looking at beat 1.8s and nice 1.6s for the same price...get my drift?

I used to be a big proponent of the 1.6 until I swapped a 1.8 turbo in mine...

Absolutely, positively, resolutely the 1.8. All day, every day, and twice on Sunday.

Unless you're swapping for an LSx!

The 1.6 chassis also came with a weaker ring and pinion and smaller brakes. Both of these can be changed out fairly easily, but do take that into account. The 1.6 dash is considerably lighter and better looking in my opinion

Buy the nicest of either that you can afford. If it's a 1.6, keep your eyes open for a complete 1.8 rear end, easiest to bolt a Torsen in hub to hub. As far as a turbocharger, either will do, the 1.8 will give you more power ultimately, or be more relaxed at the same power level. Then again, I loved my 1.6s in NA form more than my 1.8. Hoping to go turbo sooner than later.

I kinda agree with mistanfo. For naturally-aspirated Miatas, I always kinda preferred the 1.6. There is just a certain "rortiness" to those endines, for lack of a better term. Also, alot of 1.8 cars have had the same crank-nose issue that sends alot of people running from the early 1.6's. Most of it comes down to improper torque on the crank bolt when doing a t-belt. I remember Keith mentioning years ago that very few things work properly when installed incorrectly. If the crank pulley isn't wobbling at idle, don't be scared of the 1.6.

That being said, my 1.8 turbo at 11psi, poor compression, and bad wiring was just so much fun before I tore it apart to stat over. It should be ALOT more fun once it's finally back together.

And I think you are completely WRONG in saying that 200 is more than enough!!!

Anywho, buy the best example of whichever you can, and have fun!!!

200 is doable on either so just buy the nicest one you can afford. :)

Also, check out the NBs. At least locally, many are popping up for less than many of the 1.8 NAs. They are a bit nicer car, though not as nice a Miata. Stick with a 99-00 to make MegaSquirt as easy as possible.

mistanfo wrote: Also, check out the NBs. At least locally, many are popping up for less than many of the 1.8 NAs. They are a bit nicer car, though not as nice a Miata. Stick with a 99-00 to make MegaSquirt as easy as possible.

The problem is with plug-in emissions, otherwise a 99-00 would be a no-brainer. I am stuck with 90-95's for my nefarious purposes.

another +1 to buy the nicest one you can afford regardless of whether its a 1.6 or 1.8.

The 1.6 has a more aggressive cam from the factory, I think that's why they have a bit more sporting character. You can make a 1.8 act much the same way if you want, but since 90% of people who want "more power" in a Miata really want more torque down low, it's not a common thing to do.

Keith Tanner wrote: The 1.6 has a more aggressive cam from the factory, I think that's why they have a bit more sporting character. You can make a 1.8 act much the same way if you want, but since 90% of people who want "more power" in a Miata really want more torque down low, it's not a common thing to do.

For me, just simple stuff like a lightened flywheel, and removing a/c and power steering were almost enough to make my non-boosted 1.8's feel the same as the 1.6's I've had, but not quite...

Can't quantify the difference, but it's there.

I just swapped a 1.8 into my (sort of) 1992. It's not a hard swap at all. Bolted together, fired right up with out a check engine light or anything. Lots of fun with the 1.6 rear diff. My car is a 1992, but the body is 1994, with everything from my 1992 swapped over. Wiring harness, interior, drivetrain, except now the engine is from a different 1994. It's a long story, but it is a ton of fun.

That having been said, I sort of miss my 1.6. It's just different and more Miata like than the 1.8.

Joey

Change your cams if you want that revvy feel back. Heck, my old 2.0 used to run for the 8500 limiter with alacrity with some aggressive cams.

I find a stock 1.6 very slow these days :)

Just FYI one of my autocross instructors just dropped a NB1 motor into his 90 NA for like 1800 bucks. If you are thinking turbo dropping in a 1.8 even if the 1.6 is fine would not be much money.

Also all of the time trial/miata challenge guys here are running NA swaps and not forced induction for track duty

The 1.6 motor has more aggressive cams, but the 1.8 makes more torque everywhere. IMHO, if you want the "cammy" feel out of a 1.8, you can just not push the pedal all the way down until you hit 4500 RPM. :)

What's the difference between a 1.6 and a 1.8? 0.2... I feel that is fairly accurate.

I have a 90 base model w/ a 1.6 and breathing mods. I've driven a 94 1.8 and it felt so much nicer and torquier. Felt like I didn't have to rev the crap out of it just to put put around on the street. I'd definitely get the 1.8.

You won't find an inexpensive Torsen swap. Us Spec Miata guys pay top dollar for those so take that into account when contemplating cars and mods.

I also like the 99+ cars and fit a little better in them also. Those engines don't take much mods to put down 130 rwhp. I understand the desire for a project and do a MegaSquirt but not sure I'd let the MS dictate which car I ultimately want to drive long term.

amg_rx7 wrote: You won't find an inexpensive Torsen swap. Us Spec Miata guys pay top dollar for those so take that into account when contemplating cars and mods.

I did my LSD swap for ~$400, it isn't a Torsen but it works well.

1.8 Open diff housing and R&P, tired RX-7 clutch-type diff shimmed to get the preload up, and used axles and driveshaft.

I beat a horse to death for this? Not worth it....

EvanB wrote: I did my LSD swap for ~$400, it isn't a Torsen but it works better than a Torsen.

Fixed that for you...

Well I was going to say that but I've never driven a car with a Torsen so I couldn't say for sure.

Fwiw, I've got a 1990 (91?) 1.6 Miata with 310k on it. That's an early wobble nose engine.

It's no power house, but it's not an underpowered dog. No, I don't downshift when the a/c turns on. Yes, I do get over 30 mpg on average. The car has been dead nuts reliable.

Drive them. Drive several to compare and evaluate. Some I drove were dogs. This one was not. That's part of the reason I bought it.

Viscous limited slip was an option, mine has it. I rather like it. For most driving, an open differential is just fine. The little bit of inner tire grip I get with the viscous is enough, and it keeps things from getting too exciting in the rain or on leaves and such.

I would personally take a good 1.6 over a dogged and flogged 1.8 without hesitation.