Best Bang for Buck Engine Swap? (1993 Miata MX-5)
 

Alright so I have an older 1993 Miata MX-5 that was just given to me and I want to make the thing into a street legal car that is fully capable of going to the track. I plan for it to be a long, drawn out process since I don't have a large amount of money to throw at it all at once. I don't know a ton about automotive but my dad owns a shop and has been building and racing stock cars his entire life. The plan was to go to the salvage yard, find a junked miata and pull the engine. We were going to completely rebuild the engine with the best parts we could afford and drop it in the MX-5 and further upgrade it as our income allows.

This is where it gets a bit tricky. I was told by a buddy of mine that you could drop a Nissan 240sx engine, which is apparently aluminum, into the miata and cut around 300-500lbs off of the car. He said the 240 engine bolted right into the miata and worked fine. Seeing to it as I don't know a ton about cars, I was wondering if he is right and whether or not it'd be a feasible swap. I figured an engine swap should be the base of this miata project so I needed to figure that out first. If the 240 swap isn't feasible, what is an alternative engine swap that is the best for a reasonable amount of money? Mind you, me and my dad will be pulling whatever motor apart and rebuilding it with high performance parts before dropping it into the miata.

No.

Unless the 240SX engine has some kind of negative mass, it isn't going to drop 300-500 lbs off of the Miata! A stock 1.8 short block doesn't weigh 300 lbs dry! Shoot, the 1.8 long block is less than 300 lbs!

If it just bolted in with no problems, you would see them all over these forums, the SR20DET is a great engine.

In short, your friend is full of shit.

Keith

Do yourself a favor and pretend this thread never happened.

Spend some time researching this forum. And I mean like a few weeks worth of searching. Then after you get comfortable with the site, you should introduce yourself with some goals in the Newb section.

Making your first post about swapping a 240 motor into a Miata makes you look like a colossal douchebag.

I hope that helps. This is the nicest response you can expect from an introductory post like that.

k20 honda engine, its been done a few dozens times. probably the most power per dollar even over ls1 and 5.0 swaps

your motor is fine and can make more power than your experience can handle

I'd rather not play politics and make people like me by seeming to be knowledgable which I'm not. That's why I am coming to a forum. So moving on to actually trying to make some progress and learn something...

Apparently the engine in the 1993 miata is supposed to be a cast block whereas the 240sx is an aluminum block, or so I was told. The engine that I think he was talking about is the SR20. He told me that's the engine out of the Japanese 240sx which came from the factory with a turbo. I was also told that they average about $3,000 and that's probably the best bet on an engine swap since the common alternative, the V8, would make the car heavier and produce too much torque for the car to be balanced well with its horsepower:torque ratio.

With all this being said, is the SR20 a good swap to base this project off of?

No.

You sound like you have the same knowledge about cars as my 7 month old son. .

In which case I'd recommend you take the next 5-10 years to actually learn a thing or two and lets re-visit this thread then.

Because right now you're just looking more and more like a fool with every post.

PS: this is as nice of a post as you'll ever see from me. you should be flattered

Your friend is an idiot.

It does not bolt in without $3000 in subframe.

Your friend is an idiot.

Buy a MegaSquirt and some bolt ons. Dyno tune your 1.6 to 120whp.

Your friend is an idiot.

Bolt in a $800 vvt motor, tune again for 150whp. Enjoy it.

Stop listening to your idiotic friend.

Learn how to fix your car, learn what the parts of the motor do... then try rebuilding a stock motor which can be had for couple hundred bucks.

Learn how to tune it, boost with what you got, then move onto your wet dreams.

Why dump money into something you won't understand?

If the learning experience is of no interest and you'd rather throw money at the car. Just shove an RB26DETT into it. I hear it drops in. My friend says it has turbos, he read about it in a magazine, possibly. It's Japanese so it should be easy.

kids these days.


guys, I don't even know what the engine code in my car is or could tell a valve stem from my butthole


..............I think I'm gonna do a v12 swap and AWD conversion


I watched the bi and the curious, and my grandfathers uncles wife is a mechanic, so I'm good

I wasn't trying to sound rude or mean. I know I'm a greenhorn in a community full of veterans and there is a reason for that. I'm here to learn. My dad has a lot of knowledge and this is something I want to do. This is the project I want to learn on. So that's what I'm trying to do and I'm trying to get an idea of what I can and should do with this car to make it what I want so I can start saving money for it now. That's why I'm asking all of these questions. I'm sorry I've inconvenienced you guys with my ignorance but I came here to lose it. Not to be ridiculed and told that I'm a noob, which I already know.
Thank you to the people who actually have me good advice and wanted to help me out. I appreciate it.

trust me, the ridicule is not optional ;)

But seriously: wrench on this car, in stock form, to the point of actually knowing a) what you're doing with cars b) knowing the actual car and all its ins/outs/quirks/etc

Then in a few years you'll be able to even ENTERTAIN the idea of this thread.

Until then, make a normal intro and start reading/researching. You are years away from being capable of even modding the car properly and making power.

That's what I figured. I wasn't planning on tackling this project right now. I just wanted an idea of what kind of parts and engine I would need so I could start saving up for them and maybe be able to purchase them ahead of time so I'd already have them by the time I feel ready to take it on. That was the entire point of this thread. I plan to work on it and get some know-how on it. I'm also planning on enrolling in the automotive program at my college to help me out along the way. This was just for the purpose of prepping for the project.

Well your thread title is best bang for the buck engine swap and you've pretty much nailed the worst bang for the buck swap possible out of swaps that actually have kits available. Seriously, pretty much anything else will deliver more HP/$ than an SR swap. Well, I guess maybe that K-series swap might be worse. I don't really get that one either... Don't get me wrong, the SR is an awesome engine but the swap kit costs so much it kills the deal. I don't think its much, if any lighter either.

Best bang for buck is turbo on stock engine. You're good for 200hp without even cracking open the engine. Don't even get started with that "but its only 200hp" BS either. Drive a miata with 200hp then come back and talk to us. That much power in a light chassis is buckets of fun.

Well a lot of the point of the engine swap is for me to learn plus I want a monster. I don't expect it to come around any time soon but I'd like the end result to be something I can be proud of.
Is the V8 swap a better idea than the SR20? A lot of people seem to prefer the V8 swap but I don't know if it's a preference thing or if the V8 is actually just better. Also, the V8 swap is more expensive by like $4,000, correct?

Garrett,
The first thing you need to do is forget about the phrase "Engine Swap." There are a handful of us on this forum that have cars making well in excess of 300 rwhp with the Miata engine. I can tell you with 100% confidence that those power levels in a a Miata on today's commonly available street tires would useless at speeds anywhere below 50mph and then only when pointed in a straight line.

Heed the advice you have already been given. Buy a Megasquirt ECU from the good folks at DIYAutotune, learn to use it. While you are learning the ins and outs of the ECU and the software buy a complete Miata long block and start rebuilding it with your dad. A pretty simple rebuild consisting of forged rods and pistons, quality bearings, Boundary Engineering oil pump, ATI or 949 damper, Supertech Valves, springs and shim under bucket conversion will give you a proven and very reliable foundation.

Once you are satisfied with the running condition of the engine and of your tuning ability then you can choose you path to Forced Induction Nirvana. I have chosen the route of a large twin screw supercharger on a high compression short block running VP C-16 Fuel. (This setup is ideal for what I use the car for....and not much else. Let's call it a 1%er set up) but it fit my needs. For the other 99% of the people in the world I would suggest on of the BW EFR 6258 Turbos paired with a quality manifold.

You will make MORE than enough power to be "proud" and you will have a usable car that will be faster than most "street" cars.

This is about as good as it gets from the advice standpoint. If you are just wanting to be "different" for no other reason than being "different" then the SR20 swap isn't for you either. SR20s, 2JZs, 13Bs, LSXs, 5.0s...they have all already been done....so they are no longer "different." If after reading this you still have your heart set on a SR swap...then I predict that in 3 or 4 years you will have $7,000 to $10,000 sunk into a car that still doesn't run.

















Oh....P.S. Your friend is an IDIOT

Yaaaaaaawwwwwwwnnnnnnn. Good morning OP.

I love how every noob just assumes all motors just bolt right in. Yep, sure is convenient how all manufacturers make all engines identical to make it simple for us; same dimensions, same mounts, same subframe, same sensors, same electronics, same transmission, same clutch, same coolant lines, same oilpan. Just drop it right in.

On another note, how much does a BP block weigh? I know I've carried them around the garage and loaded them in cars to transport, and I certainly can't imagine myself lifting much more than 100lbs.

The bare block itself is nearly as heavy as a complete long block D series honda engine (also iron block). :giggle:

The really cool swap for the Miata is the Rolls Royce Merlin V12 from a Supermarine Spitfire or North American P-51 Mustang.

Or, you could go more modern and do a gas turbine. Flamethrower!!

Seriously, cut your teeth on maintaining/restoring the stock car. Do the ECU and learn to tune.

DON'T SPEND A DIME ON ANY OTHER "SWAP" PARTS. IF YOU DO, YOU ARE THROWING AWAY THAT MONEY BECAUSE YOU ARE GUARANTEED TO BE BUYING THE WRONG THINGS AT THIS POINT. YOU ARE IGNORANT AND YOUR FRIENDS ARE IDIOTS (except, probably, your Dad -- talk to him instead of your friends).

With your Dad's background in stock cars, an LS conversion seems like the best swap down the road. Would be an awesome father/son project.

I blame fast and the furious... lol "But guys, if I don't engine swap my car, how will I ever go fast"!?

I just shipped a bp6d long block with clutch and mounts to dopple. No manifolds or accessories tho. I was very surprised it was only 305lb dry. Short block is probably close to 200lb I would guess

gotta get those SPOON engines in time for race warz, or johnny tran will disrespect your famiry.

Lol, I picked up a bare d-series block for a friend with one hand and put it up on the top shelf of his super cheap particle board shelves. Couldnt have been more than 40 pounds.

Well AN engine swap will be necessary. My miata has a 1.6 in it and if I stayed with a miata engine, I'd put a 1.8 in it. Regardless, my current 1.6 has too many miles to be playing around with, or so my dad told me. He said the best idea would be to get a junkyard car with a 1.8 and rebuild the engine. Plus during all of this, the car needs to stay a commuter car. I figured if I'm putting a new engine in the car regardless of what happens, why not go big?

See you THINK you know what you're talking about and what you want, but you really don't.

you reallllllllly don't

Mileage is irrelevant. Unless engine runs like crap you don't need to do anything to it.

You're all over the place - I want a big nasty project, I don't have much money, I want to do complicated swap, I have no skills, I want this to be a monster, I need this to be a commuter.

You sound like the typical idiot 15 year old kid that doesn't have the faintest clue about wwhat you want and need.

Step 1) Go to daddy's "shop".
Step 2) Ask for a "compression tester"
Step 3) Do a compression test.
Step 4) Compare numbers to what is known to be good (use interweb searches for this)
Step 5) Realize your engine is just fine.
Step 6) Forget about being a ricer with all the horsepowers.
Step 7) Start reading up on chassis/suspension modifications
Step 8) LEARN TO DRIVE THE FUCKING THING FIRST.
















BTW- Your friend is an IDIOT.

Well the car does have some issues as it sits. Oil leak and some other things.
I do want a big project and no I don't have much money. That's why I'm trying to get an idea of what to save for right now before trying to start the project. The project would start way down the line. I want this car to be a monster but in the mean time I have to have it as a commuter.

Your dad works on American cars primarily, doesn't he?

There's no such thing as 'too many miles' on these cars. I've seen people on this forum pull apart engines with 250k miles on them with perfect crosshatching still.

But you've answered your own question BTW. Best bang-for-the-buck swap in a '93 is a 1.8.

Motor is leaking oil? May as well junk the car.

Just start saving as much as you can then and don't worry about what to buy. Read and research as much as possible. Once you actually understand the car you will have a much better idea of what direction you want to go in, what is realistic, and what it takes to get there. You will need money for the project no matter what so just save with no concrete plans.

Yeah that's what I figured I should do. Thanks. I appreciate the advice!

Also, yes my dad specializes in Chevrolet vehicles.

Ha! Called it. Talk to your Dad instead of your friends. He's a lot smarter than you think.

Oh yeah. I know. Haha. I'm talking to him more than my friend.

Save up 15 grand if you want to swap in anything besides a 1.8L from another miata.

This. Way too many people underestimate the amount of money it takes to properly swap an engine. I'm helping a friend with an SR swap into a 240SX and even though the engine was designed for that chassis it still costs a few grand before you get around to buying the engine. There's way too many people that think that because people go around doing $200 engine swaps for lemmons racers, that anyone can do the same thing. Trust me, you can't. If you want a smooth running well sorted car, its going to cost.

buh-bye.

Aw, hope you enjoyed being around smart people while it lasted.

Did some posts get deleted? I always miss the real fun.

I don't see the reason for the ban? Were there some deleted posts where he got shitty? If so, can you restore them so we can enjoy? :D

Keith

Nope, just too stupid to be allowed to post. Quality Control Bot is a Bawss, and cleanses this site of contaminants such as OP

And, the QCB did make an early appearance, so one can't say there wasn't fair warning.

Hopefully, OPs Dad takes him to the shed for some schooling.

I thought the ban was unecessary, just sayin.

Yea me too... only because this is some funny ass shit to read when I have some free time at work!!! :giggle: ha ha

Hai guyz muh freends says that da Volvoturbo motor is the best swap. My mom works on Fords and it's good.

Maybe when OP matures a bit he can create a new account. I have no problem with one less OMGZ SR20 IS TOTES AWESOME LOLZ account.

Sorry to necromance a thread, but it seemed like an appropriate thread for my question.
Speaking of less common swaps that are probably uncommon for a good reason...(putting on flame suit)...
There are a lot of 1.8L Miata engine swaps. What about the later 2.0L NC Miata? Is that too different to swap easily? I'm guessing the mounts are probably all different. What about the bell housing bolt pattern?

What about a same year 2.0 from a 626 into a Miata, say a 2000. (I have a 2000 Miata with a bad engine. And (93-02) 626s with bad transmissions can be picked up cheap.) Obviously the ECU and sensors would need some work, probably major work but will the trans and mounts bolt up.

Not making firm plans, just curious.
Thanks,
Idiot

If you're going for an F engine, Concealer404 will tell you F2 or bust.

There are a few seriously awesome FE3 swaps on here also, check the build threads section. Find a Kia Sportage and go to town.

If you're going to swap a motor, make sure it's a better motor than what you're replacing.

Hint: The 2.0 in the cars you're referencing is called the FS-DE and it's one of the worst things Mazda has ever done. Has next to nothing in common with the F motors that don't suck dick.


As for the MZR: Been done. Maybe twice. Different bolt pattern, whole host of other challenges. Probably not something to attempt if you're asking these questions. (No offense meant, i wouldn't try it, myself.)


I like the F2, and will put one in a Miata myself, but won't suggest anyone else do it, as it won't clear the hood. FE3s are cool, though.

Ban was premature. If we don't educate the noobs, where else are they gonna learn? From the "SR20 swap" friends? Father sounds more reasonable. Maybe he told the kid to do some research, instead of just telling him he's wrong.

At least he wasn't getting all butthurt over it. I think he is/was just young and ignorant. It is our responsibility to correct that, not just shut them out.

You're talking about a ban that happened 13 months ago.

Like OP, he didn't bother to read :)

Thanks guys. Yeah, most any engine swap is out of my league at this point, just curious. I do dream of doing a DISI MZR (Speed3) transplant into a Miata "some day".

Were you just receptive to advice/comments with less than 20 posts to your name? I have no idea how to handle this. :giggle:

Shit, ive pulled several motors, been wrenching on big jobs in my spare time (turbos, clutches, pulling engines to build etc) for like 8 years and after looking at the cost and complexity of putting anything other than another 1.8 in my NB2 ive all but given up.

The miata gets a reputation as this easy swap platform since lots of people with time and money do it, and it makes average Joe think its as easy as just dropping another motor in. Hell, i had dreams of putting a K series motor in mine until i really started doing the time and math...

Ive also been tuning mazdaspeed3s for a few years since ive owned 2 lol, and ive thought more than once about one in the miata. Awesome as it would be, it would just be a massive pain in the ass.

/\ I'd tend to agree. When you really plan out a complete swap, not just have a wet dream about doing whatever, but actually sit down and think through the whole thing, it's never as easy as it seems at first.

I have an irrational desire to build a DISI MZR-powered Rx8 someday. Something tells me that with an NC subframe and transmission, that car would basically assemble itself.

What ever happened to the guy who was doing a Yamaha/Isuzu/something V6 swap into an RX8?

Fuck the DISI motor, the HPFP makes you take a 5" hole saw to the firewall for clearance. The 2.5 MZR has a better power potential anyways. But I hear ya on the NC sub frame. FM Keith says the RX8 subframe fits the NC chassis, so the opposite is probably true. Not sure how the engine position would work out in relation to the firewall or hood with that setup.

But lets talk about the MZR swap. We had one posted on this forum, and I saw a 2nd in the life and talked to the guy who built it. The one I saw was an off the wall road race car and had the firewall channeled like 4" back, the entire motor including the crank pulley was behind the steering rack, and practically behind the subframe. I believe there's a couple more floating around. I'm highly confident we can make this motor fit a stock unmodified subframe car with just the NC oil pan. And of course there's the option to put transmissions capable of 600ftlbs of torque behind it using only unmodified off the shelf components. You can pull the 2.5 version out of ford escapes for ~$600 all day, literally check car-part I bet theres more 2.5s near you under $700 than there are of the good k24s. They're also good for 350-400hp on stock internals, or around 200 wheel with bolt ons, tune, and cams. Now figure this, you can get a motor for $700, a rated to 500ftlbs road racing 310ftlbs drag racing tranmission for ~$2500 or just one rated to 300ftlbs for ~$1200, and then a swap kit that is just engine, tranny, and diff mounts. You're taking about a motor swap that gets you basically what a built BP gets you for power handling, but gets you a tranny stronger than the 6 speed, no more vibrations breaking shit, and ~70lbs off the nose, all for around the cost of what it costs to do a full build on a BP. That sounds damn enticing.