S14 - Overrrated or Underrated?

[2mAn]

Seems like more and more I am hearing that the S14 is an overrrated motor. Is this true? Is it ONLY true on a stock S14B23? Does a 2.5L change that ? I've even seen a 2.7L conversion with a square 95/95 setup now...

Discuss

[mavrikno13764]

s14 sucks on the street. Perfect for track weapon.

[2mAn]

s14 sucks on the street. Perfect for track weapon.

What mods are a MUST?

[MrBurgundy]

The extra displacement really would help the shit part of driving an s14 on the streets... but even then, its a strung out 4 banger... Sounds like a 4 banger.... 4 banger is forever meh- with the exception of some carbed ones.

The s14 is also expensive to maintain... If I had an e30 M3, I would sell the s14 and put an S5x in it.

I've seen some S14s sell for like 25k for the 2.3 variant..

OVERRATED

[reelizmpro]

It depends on how you use it. Now remember it was built for racing a lightweight car around a track. The detuned version had to be made for the street car for the M3 to exist. This distinction needs to be made because most expect the modded version and are disappointed with the street version, although 192 or 215HP from a 4 cylinder 2.3 was the most HP per liter of any production engine at the time. By nature you have to Rev the piss out of it to reach peak power which is perfect for open roads but not so much in stop and go traffic.

I drove mine daily in the late 90's and grew tired of it. In city traffic, it feels slower than most cars. Instead of swapping in a 24v, I bought an 88 325iS to use as a daily driver. The 325i does many things well. The M3 does only one thing well. Love it or hate it, but that's what it was designed to do.

With values increasing, the nice low miles stock ones fetch a premium but I guarantee you those are the ones that will disappoint you the most when you drive them especially since they are only getting older. Drive a well sorted, modified car and it's closer to the true experience of how it was intended. The street (stock) engine is overrated nowadays because technology has advanced. The modified engine is underrated because it can make 330+HP from a NA 4 cylinder, the problem is few can afford to do it as it's very expensive and isn't going to be as reliable.

Many may not realize this but BMW has a catalog of motorsport parts specifically for the S14. So it's a lot more than the common 2.5 stroker kit. There's an upgrade for nearly every single part. The street engine while good, is a far cry from the race version.

[McGyver]

What mods are a MUST?

Do you have one now? Or getting one soon?

[BlackbirdM3]

Its a brilliant engine. Its great on the street, reliable, take it to the track and let it sing. Can it benefit from some minor bolt on mods? Yep, a light flywheel is an awesome upgrade, but that is true on almost any performance engine. A bigger set of cams, yeah, maybe. A better chip, yes. My car drives so much better with an aftermarket IIGO chip vs stock.

Does it make a mile of torque at 500rpm? No, its not a diesel truck engine. Low end torque is overrated, especially when its out of breath at 5k rpm. Its much like driving a turbo engine that has a slightly too large turbo. It takes a moment for things to spool up, but okay, not a big deal. Do you really need to do a burnout from idle? IF yes, rev it, drop the clutch and roast away. The real answer is, no. There is no reason to need to roast the tires from a stop sign. It gets great mileage rolling down the freeway at 80. Yep its turning 3400(ish) rpm, who cares. Its not like its working hard. Take it to the track and spin it to 8K all day long, and then do it again the following day, and then drive it home.

As for expense to maintain, after 13 years of owning one, I haven't found what is that expensive to maintain. Any 16 valve engine 4cyl is going to cost $$$$ to rebuild. Valve adjustment is easy, but you do have to have a small amount of knowledge on how to work on mechanical things. There are no rocker arm assemblies to fail, the rod bearings are wide enough they won't just fail. (Unlike and S54.) If the rod bearings do need to be replaced for some reason, they can be done in the car. It was designed as a race engine, so doing stuff in the car is for the most part, not that bad.

We got screwed here in the states with a very detuned engine, but still, 192 hp isn't bad. Its not that heavy of a car. Still, I'd rather have gotten the Euro spec engine that was 212hp. Or, the Evo 2 version that had a different set of cams, and a different chip that made 217. Oh, yeah that 2.5 liter version, 235hp. That is only 5 hp less than the S52 (Which is barely an S engine at all. Yep there is a big torque difference there, but also a big weight difference as well. The main reason BMW chose the S14 over a 6cyl was weight. They figured the lack of weight was a great tradeoff for less torque, and I agree. After driving my M3 for the past 13 years, if I get in a normal E30 or E36, the first thing I notice is the very forward weight bias. Its not a good tradeoff. In the case of an E36, yep its got more power and torque, but god do they handle poorly. The front end is just too heavy. An E30 is better, but I wouldn't say its good. This is part of the reason the E30 M3 is such a legendary car, and all the M3s that have followed have failed to live up to the fame (Checks internet for most winning touring car in history... Oh yeah still the E30 M3.)

If one likes V8s they won't like an S14 as its a totally different creature. Personally I can't stand V8s. They sound like shit, tend to be too wide (screw 90 degree engines) have pushrods, counter shafts, and other crap that.V6s also sound like crap and suffer similar issues. Straight 6s sound beautiful, as to V12s. Neither one is going to be really light however.

The S14 is an amazing engine, that isn't for everyone. Its a limited production engine, but a very well designed and executed one. Yep its got some harmonics at high rpm, Okay so what? All large displacement 4 cyl engines do. Yep, a straight 6 or V12 is smooth as silk (usually) I'm not going to argue that. Still, they suffer from weight issues.

Personally I like race engines. I like max torque above 6K rpm, and redline beyond 7500 rpm. This combo makes for a much more fun and engaging experience to drive. If this isn't you, then yeah, the S14 isn't for you. Go find a truck engine and enjoy.

Will

[E30SPDFRK]

Great engines when viewed with 35 year old glasses. It's a very cool vintage motorsport engine that can made to perform really well for its age (and is one of the best sounding engines out there), but as a modern street engine, its pretty underwhelming. The 2.5 crank is almost necessary if you plan on driving it daily. The high HP ones take a lot of work to get there, and don't have a long lifespan when you do. It's possible to make 300+ hp on a race engine, but don't expect more than ~240-whp on a still streetable engine.

[e30davie]

They certainly command high $$. and weather the price is justified for history/nostalgia/period correctness, only you can decide. things have come along way since, but no modern engine will be an e30 m3 motor. You can probably do a honda K series RWD for the price of a broken s14, but it will never be an s14. (Exaduaration maybe, but you get the idea)

[FredK]

Great engines when viewed with 35 year old glasses. It's a very cool vintage motorsport engine that can made to perform really well for its age (and is one of the best sounding engines out there), but as a modern street engine, its pretty underwhelming. The 2.5 crank is almost necessary if you plan on driving it daily. The high HP ones take a lot of work to get there, and don't have a long lifespan when you do. It's possible to make 300+ hp on a race engine, but don't expect more than ~240-whp on a still streetable engine.

Yep, exactly.

The stock S14B23 might not be impressive by modern standards, but it was developed in the mid 80s, when 192 hp was a lot for a 4 cylinder engine, and likely among the highest hp/L naturally aspirated engine at the time. I don't consider it to be overrated at all, considering the era it came from. I don't think many NA 4 cylinder engines in 1986 came anywhere close.

Modern S14 ownership isn't that easy, because the engine is very pricey, and a lot of the components have been discontinued, but some of the discontinued parts are supported by the aftermarket.

[mavrikno13764]

What mods are a MUST?

Carbon Airbox, Let that intake sing to you whenever you can!

[varg]

I have no experience with them so feel free to stop reading there but I doubt the engine is overrated if you view it through clear eyes instead of expecting it to be something that is worth what M3s and S14s cost these days. I've seen what they sell for and as a value proposition they're definitely total buns, probably some of the worst performance per dollar on the engine swap market. It's an old 4cyl engine that it makes some decent power but E30 M3s, at least the US models, are not super light at ~2,800lbs+ unless you start pulling stuff out of them they're so they probably feel pretty gutless for normal driving, much like an S2000. Judged in isolation of the M3 they came in, I'd never put an S14 into anything because they don't do anything that a K-swap won't do for less money and weight and I'm not rich... I guess I wouldn't do it even if I were rich because I wouldn't be spending tens of thousands on sub 300hp 4cyls with a V12/4 rotor budget.

[e30m3s54turbo]

I bought a new m3 in 1990 it was fast in its time. It lacked torque but you had to rev out to 7k to have fun on street and track.
I have two m3 no s14 in them. I love the race history on the s14 but bmw never built a other 4 cylinder m car. BMW built six and eight. Now turbo six.

[BlackbirdM3]

Great engines when viewed with 35 year old glasses. It's a very cool vintage motorsport engine that can made to perform really well for its age (and is one of the best sounding engines out there), but as a modern street engine, its pretty underwhelming. The 2.5 crank is almost necessary if you plan on driving it daily. The high HP ones take a lot of work to get there, and don't have a long lifespan when you do. It's possible to make 300+ hp on a race engine, but don't expect more than ~240-whp on a still streetable engine.

Who the hell needs 240+ HP in a street car? I mean really? Its not a fatass 4000lb car. I will say I have yet to lose and autoX to a newer M3 on street tires. I'll go a step further, and say my engine is tired. I know it is, The odometer says a little shy of 187K miles, but we all know how easy it is to swap a speedo. I cannot think of a time when I needed more power than I have. Hell, I chased down a new vette on a backroad with my M3 fully loaded with all my camping gear, photo equipment, ect, with a full tank of fuel. The guy was going pretty well, but I caught him and he gave me a point by. I never saw him in my rearview again after the 2nd corner. Sure, to make a pass in a short passing lane, HP is nice, but even then, do you really need to make a sketchy pass?

I will say that when I go though my S14, its getting some headwork done, the most beautiful 2.3L crank I've ever seen, and a set of cams (Evo3 intake, E2 intake on the exhaust) a 9lb flywheel, a light set of pistons, and a better header. I'll bet that should come close to 200 at the wheels, and I'll call it good. It will be a rev happy, reliable engine that will go another 200K miles. Will the rebuild be cheap? Nope, lots of machining to do, and machine work isn't cheap. Still it will be a one time expense. My one regret is that I can't pitch the EFI in the trash and run carbs. I can't tune EFI myself, but I can tune carbs. (I really hate EFI. Computers belong on your desk, not in a car.)

Will

[ZeKahr]

Overrated for regular street drivers? Sure

Overrated for the guys that try to flip E30 M3s on BAT for max profit? Oh no, they’re very underrated to those people

Either way, good luck getting good quality parts for this thing. Even if some of the NLA ones are repro’d by the aftermarket, they probably won’t be the same quality as OEM unless that manufacturer is known for putting out quality repro’s