Do you have a M20 hot rod or swapped Motor?

[Wanganstyle]

I have an ix, so an M20 makes a lot more sense. I'm done with M20s for now, and am working on something else - a swap in an ix, done right, will cost way more than a built M20. It really wouldn't make sense to do an M5x or even S5x swap in an ix, the power gains over a built M20 are just too small for the effort (I have about 210-220bhp with the M20).

also, comparing a $500 junkyard M50, to a brand new, custom built M20 with go-fast parts is stupid. If you built the M50 the same way it would cost far more.

M20s:
-simple to build
-cheap to build (relatively)
-easy to tune
-light
-sound better
-rev higher

M30s are cool too, just not my cup of tea.



this is absolute nonsense. All of the high reving M motors have a much longer stroke than a stock M20 or M50. the S54 has a 91mm stroke and revs to the moon. a properly built M20 with good headwork will do 7500+ no problem. an S5x reving that high will probably collapse a hydraulic lifter and be left permanently ticking. :p

M5x and S5x aren't exactly high reving engines. Not unless you throw a ton of dough at them. A set of schricks cost what, $2k? then you have 24 valve springs to replace, and you probably don't want to keep the hydralic lifters, so you'll need 24 aftermarket lifters, etc. etc. People have this illusion that you can build a 24v motor cheap, it's 100% BS. It's only cheap if it's a bone stock junkyard pull. building a 24v head probably costs 4x as much, and there's 2x as many parts.

building a pedestrian 24v to "high-er power motor" usually just results in a similar RWHP to a bone stock e36 M3 USA spec; not enough

people are swapping out the s52 of e36M3 usa spec all day long; s52 does not make enough power for 2012.

S52 running obd1 is a joke. S50 running obd2 is a even bigger joke; illegal reverse motor swap like putting in a Cable tranny B16a into a EG or ek hatch and then converting the newer hydro clutch to cable. GHETTTTTTO.


S50 usa spec is falling apart by now; garbage leaky slut motors from smashed old 95 m3's. A proper rebuild costs more than buying a e36M3 running and driving.

A dinan s52 supercharged E36M stage 1 laps at the same pace on the track as a stock power S52 e36M. no real difference LOL

S54 in stock form blows the doors off any s52 build up. Don't even think about revv-ing the S52 in any built form over to 8000+ like an S54.

[spike68]

I see some of you guys saying its tough to get decent numbers out of an m20 N/A, but im curious as to why this is difficult.

Can someone explain this to me?
Is its engine design? Materials used?

Im just curious to know. Gain some knowledge :)

[slammin.e28]

Timing belt.

[nando]

I see some of you guys saying its tough to get decent numbers out of an m20 N/A, but im curious as to why this is difficult.

Can someone explain this to me?
Is its engine design? Materials used?

Im just curious to know. Gain some knowledge :)

it's not difficult at all. you aren't going to make 300hp out of an N/A M50 any more than you can out of an m20. it just costs money.

[Wanganstyle]

Timing belt.

non issue.

m30, m20, m50/s52 .... all dont make any power.

you need a real engine designed for power to have power.

S38, S54, S50 euro. real WBS Individual throttle engines; BMW sells M cars for those who want to purchase "power"

The standard for power in NA format for ANY high performance engine has been minimal 100hp/per liter for over a decade now.

[evandael]

power = money.

any motor can have a ton of custom, high performance parts thrown at it to reach or exceed that magic 100hp/L mark. and those motors which already exceed that mark from the factory cost quite a bit of money to maintain, or heaven forbid, rebuild.


by the above rationalization, an LS2 doesn't make 'any power' because of it's single TB and paltry 66.7 hp/L. pppfffft. it's one of the best deals ever in terms of power to cost.

[VinniE30]

this is absolute nonsense. All of the high reving M motors have a much longer stroke than a stock M20 or M50. the S54 has a 91mm stroke and revs to the moon. a properly built M20 with good headwork will do 7500+ no problem. an S5x reving that high will probably collapse a hydraulic lifter and be left permanently ticking. :p

No. It's not nonsense at all. You just gave anecdotal evidence of there being a high reving engine with a longer stroke than bore. I didn't say there were none, of course there are high reving engines with more stroke than bore. The high reving motorsport inline 6's have a larger stroke for better torque for better daily stop and go use, better fuel economy, and the fact that they reached the limit of how much that block can be bored out safely. But if you're designing your own engine to be high reving, not one that is from the factory designed and tested for years by engineers, then increasing stroke is risky for a high reving engine.
The fact is that for high reving engines it's better to increase bore than stroke for a number of reasons.. piston speeds, stress on the crank, harmonics and balance, better flow at higher rpm...

[Roysneon]

I swapped an M50 into my car. I have no real regrets. I blew the old M40 that was in it and had the M50 on hand. For my purposes the M50 is fine. The only thing I would have done differently is to have done a rebuild and more maintenance to the engine. Since I needed the car back up and running I didn't have the time and since it was an 'emergency' swap I didn't have the extra cash on hand.

I'm not really bothered that it doesn't make 300hp, or even 200. I don't think that it would be reasonable for me to spend 10k+ on an engine swap into a car that cost 2.5k just so I can drive it to work and take it to a lapping day 3-4 times a year.

Oh, I also had an M20 on hand. It would have been very easy to drop that in with no guesswork, no wiring issues, using all factory E30 parts, but I still chose the 'low power, old, pedestrian' M50. I'll admit that I was nervous that my unrebuilt, un tested 24v would be crap; however it ran great at first startup and has run better than my m40 usually did.

In the end I believe its all about scope. Most people build what they want to for reasons that can't be explained with facts and figures. Is it news to people with a 3.0l m20 with custom headers, engine management and a cam that they could make more peak power with an S54? I sure hope not.

[VinniE30]

non issue.

m30, m20, m50/s52 .... all dont make any power.

you need a real engine designed for power to have power.

S38, S54, S50 euro. real WBS Individual throttle engines; BMW sells M cars for those who want to purchase "power"

The standard for power in NA format for ANY high performance engine has been minimal 100hp/per liter for over a decade now.

Get off your high horse. Seriously every thread about engine swaps you come in and say how pointless m5x swaps are and how if you want power go s54 or euro engine.
m30, m20, m50/s52 .... all dont make any power????????? really?
Lots of people are happy with their m50 and s52 swaps. And most people will tell you that it's plenty power for the light e30 to handle. S52 e30s usually have around +100hp on the stock m20, and the car still weighs the same. They are on par in acceleration with "new" sports cars.
You can make the same argument you made for the "real" motorsport engines for anything: "S54 doesn't make any power, just do an xxx swap and get 1000hp or it's pointless"

[nando]

No. It's not nonsense at all. You just gave anecdotal evidence of there being a high reving engine with a longer stroke than bore. I didn't say there were none, of course there are high reving engines with more stroke than bore. The high reving motorsport inline 6's have a larger stroke for better torque for better daily stop and go use, better fuel economy, and the fact that they reached the limit of how much that block can be bored out safely. But if you're designing your own engine to be high reving, not one that is from the factory designed and tested for years by engineers, then increasing stroke is risky for a high reving engine.
The fact is that for high reving engines it's better to increase bore than stroke for a number of reasons.. piston speeds, stress on the crank, harmonics and balance, better flow at higher rpm...

it's nonsense because inline 6's are inherently balanced. Plus there are TONS of high reving BMWs engines with longer strokes than 75mm, and not just 6's (S54, S38, S14, S62, etc. etc. etc). How is that anecdotal?

harmonics are not a big deal with any crank that you can buy from a factory engine. you'll have a harder time getting good VE at high RPM than you will building a bottom end using an 89.6mm crank that revs to 7500+ rpm. That's easy using 100% stock parts. I do 7500 on an unknown-miles, bone stock eta crank and stock, used S52 rods. still anecdotal?

you don't get "better flow" from a shorter crank or larger bore, either. you get better flow from headwork. also, you can't really go above 2mm on an M20 or M50, and that won't really give you much at all for more power or displacement.

[obrian]

I had the basic moded m20, mark D, 19lbs, exhaust, filter. The m20 is a cool motor, sounds cool, has a good powerband. 4.10 gears and it was fairly quick, but not fast. I dont think its a good motor for na power. Just to much money for not alot of a gain. The motor is already pretty well optimized from the factory.
But saying all that. It was practically built for turbo power. Just about perfect compression, strong bottom end, strong tranny, lots of room for the turbo and intercooler. For those that complain about a bad powerband. Thats why they make so many diferent turbos. You can easily use a turbo that boost very early and stills builds boost to 300hp. You can use electronic boost controllers to boost when and how you need it to. Or you can make 500hp on a stock block. Crazy numbers from a factory non turbo motor.
But when you build a turbo motor, I think you gota fix the little things. Head studs, clutch. Thats about it, simple stuff. You can do it with the factory dme, but pnp megasquirts are simple and easy. Thats what I used. But I didnt fix all the little things and this is what it looks like right now.

[Wanganstyle]

Get off your high horse. Seriously every thread about engine swaps you come in and say how pointless m5x swaps are and how if you want power go s54 or euro engine.
m30, m20, m50/s52 .... all dont make any power????????? really?
Lots of people are happy with their m50 and s52 swaps. And most people will tell you that it's plenty power for the light e30 to handle. S52 e30s usually have around +100hp on the stock m20, and the car still weighs the same. They are on par in acceleration with "new" sports cars.
You can make the same argument you made for the "real" motorsport engines for anything: "S54 doesn't make any power, just do an xxx swap and get 1000hp or it's pointless"

it is pointless to swap when there is a great engine original to the E30 already installed.

its called a M20. even in m20b20 form its quite nice and takes well to turbocharging.

if bothering to change; put in a real motor. or a American V8!

[Exodus_2pt0]

Its a honda its made to be rev'd out, & the f20c makes more power per liter than any other motor in the world

Wait what?

F20C 240hp/2.0l= 120hp per liter.

Hayabusa engine:
194hp (crank)/1.3l= 149hp per liter.

Honda is a great company, and they design very awesome machines. My 09 CBR 600 was my favorite motorcycle I've had the pleasure to own... But to make a claim that their motor makes more power per liter than any other in the world is outrageous.

[TheTacoMan]

Personally if I was going to swap a motor in, period correct motors mean more to me which is why I would either choose a s38 or a m30 both boosted. Hell a boosted s14 would be pretty fun too.

[broach328]

it is pointless to swap when there is a great engine original to the E30 already installed.

its called a M20. even in m20b20 form its quite nice and takes well to turbocharging.

if bothering to change; put in a real motor. or a American V8!

your contradicting yourself and making claims with no supporting evidence man first you said we need euro motors or s54s because s52 was not enough power for 2012. its safe to assume most peoples e30 weighs around 2800 lbs. with an s52 that puts you at 11.66 power to weight ratio. The new scion fr-s is also 2800 lbs but with 200 horsepower giving it a 14.0 power to weight. I mean if your setting your goals high and want to be comparable to 911s or e92 m3s then I agree youll need s54 or better but I would imagine most people arent looking to spend 6k on a swap with more power than an e30 can actually use. and i dont know what to think of the american v8 comment. my point is, for an e30 you dont need 350 hp to keep up or even beat the current "sports cars" of 2012.