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.