anyone still doing m30 swaps?

[AWDBOB]

An M30 would be a great swap as long as wasn't stock. stock it does not provide enough benefit IMO

That's an interesting thought.

I did a bunch of M30 research when I was planning on swapping, and the M30(b35 mostly) really seemed to peak hp-wise around 220whp (280-290 cam, head work, high compression pistons), which is around where a properly built M20 hangs. Granted, there was a bit more meat under the curve, but the parts required for the M30 to get there shifted the powerband, morphing it's standard "torque benefit" over an M20.

Seemed people could effortlessly pull 180-200whp out of an M30 with bolt ons, but going above that the results were extremely minimal. I don't know if it's because of M20 aftermarket support or what, but M20 strokers, at least on the internet, going through dyno simulations (lol), appear to do better when applying similar modifications to both platforms. That "cheap way to 200whp and phat torque" is the only reason why the M30 was of interest to me.

On paper what I just said doesn't add up, because both the b25 m20 and b35 m30 are similar in how they make power, but it's just something I noticed time and time again.

One thing I did notice is that when an M30 car received ITBs, it had a HUGE bump in power over what one would typically see of an M20 car. Perhaps stock M30 intake is just that bad? Maybe the b35 head is worse and requires more work to take advantage of the increased displacement?

The other m30 bummer is that if you want to build a stroker motor you have to track down S38 parts, and you can't bore an m30 block very much.

Anyway, just rambling....carry on gents.

[Bearmw]

I found that Bavauto long tube headers fit with minimal modification. I used Good&Tight B35 mounts and all I had to do was grind off a small casting protrusion on the block. I think it is a very fun motor.

[lukeADE335i]

I still love mine! I think the biggest problem to new swaps now is availability.

Much like e30s at the wreckers, e34s & e32s are also becoming harder to find!

[e30m3s54turbo]

I love the m30 in a e30. I’m in process of doing a m30 in my silver e30.

[digger]

That's an interesting thought.

I did a bunch of M30 research when I was planning on swapping, and the M30(b35 mostly) really seemed to peak hp-wise around 220whp (280-290 cam, head work, high compression pistons), which is around where a properly built M20 hangs. Granted, there was a bit more meat under the curve, but the parts required for the M30 to get there shifted the powerband, morphing it's standard "torque benefit" over an M20.

Seemed people could effortlessly pull 180-200whp out of an M30 with bolt ons, but going above that the results were extremely minimal. I don't know if it's because of M20 aftermarket support or what, but M20 strokers, at least on the internet, going through dyno simulations (lol), appear to do better when applying similar modifications to both platforms. That "cheap way to 200whp and phat torque" is the only reason why the M30 was of interest to me.

On paper what I just said doesn't add up, because both the b25 m20 and b35 m30 are similar in how they make power, but it's just something I noticed time and time again.

One thing I did notice is that when an M30 car received ITBs, it had a HUGE bump in power over what one would typically see of an M20 car. Perhaps stock M30 intake is just that bad? Maybe the b35 head is worse and requires more work to take advantage of the increased displacement?

The other m30 bummer is that if you want to build a stroker motor you have to track down S38 parts, and you can't bore an m30 block very much.

Anyway, just rambling....carry on gents.

The m20 and m30 both encounter a hp wall when using the stock intake manifold. The manifold restricts the amount of air it can move (compare “cyl head flow” vs “cyl head + manifold flow” from a bench it drops off quite a bit), also the runner length is too long to function properly at higher rpm (it was designed for solid midrange). If you are serious about making NA power with either then abandoning the stock intake manifold is a must.
I don’t know what the m30 head flows stock but I recall it’s a fair bit more than the m20 and they can move a lot of air when ported (much more than an m20). However the m20 seems to be more efficient in converting things to hp I guess it’s a better combustion chamber port layout and valvetrain capability that fits the capacity better (i.e. M30 is valve train lift limited).

[george graves]

I'm sure you can make a m20b25 make more HP than an m30b3x stock. Of course. But they are two different things on the street. If we're talking built motors, then all bets are off!!! So swap to swap, I;d rater swap in a m30 for $2.5k then build a m20b3x for $7k. That's just me.

[varg]

A m30 is all about the TQ curve and not about numbers. It's the table top looking TQ curve that makes it a great daily driver for a e30. Remember phz class where it's all about the area under the curve? This is that.

MPG's suck, but not any worse then say a pickup truck I guess. Really slamming it around town it's as low as 12-14 mpg, but tip towing it around it's still 18. 22ish highway?!?!? I've only gone on one long trip, and just remembered it was thirsty like a big SUV would be. The weight thing gets over blown. Now, would I recommend it today??? Sure? Kinda? M30 last forever. But a m6x is a better swap, but 4x the work. Now if you want to compare a m30 swap to a m50 swap - the m50 is a joke.

When talking about output characteristics, area under the curve and such and mentioning fuel economy, M54B30 is a good modern alternative. Very similar dyno plots if you compare them, only the M54 makes a little more power and makes peak torque earlier. AFAIK the M54B30 is lighter and possibly a little shorter in length?

[LowR3V'in]

biggest thing i don't like about the m30 is that it doesn't rev past 6.5.
it just dies. i think if anyone comes out with a shorty intake manifold it would change the game.

m20 doesn't seem to care it'll rev out pretty nice with the stock manifold.
but then you have to really boost it hard to get it moving. My old m20 i had 30psi for some time then windowed the block.
m30 feels the same at 18-20.

[Anthony B]

biggest thing i don't like about the m30 is that it doesn't rev past 6.5.
it just dies. i think if anyone comes out with a shorty intake manifold it would change the game.

m20 doesn't seem to care it'll rev out pretty nice with the stock manifold.
but then you have to really boost it hard to get it moving. My old m20 i had 30psi for some time then windowed the block.
m30 feels the same at 18-20.

This should be short enough lol

Untitled by Ant Bolic, on Flickr

[ForcedFirebird]

This should be short enough lol

That thing is sweet. I see you on Instagram :P

[LowR3V'in]

ya that's why i'm excited about your build

[digger]

This should be short enough lol

Untitled by Ant Bolic, on Flickr

i'd take a set of trumpets or spacer a couple inches longer and swap them out the dyno. should only take 10min but will help you see what makes the engine happier

[Anthony B]

i'd take a set of trumpets or spacer a couple inches longer and swap them out the dyno. should only take 10min but will help you see what makes the engine happier

Have two different sets of spacers to take along for tuning, will be interested to see how it responds with the lengths & go for one that have a good hp/torque balance.

My head flows more volume on the intake at 9.4mm of lift that a race ported m20b29 head that is on Rama’s race car, I think the limit to to m30 is the responsiveness compared to the m20 going to tie it down to the weight of parts with more or less every part being heavier, valve lift is definitely another limit with small rocker pads limiting the duration/lift options, though the metric mechanics new rocker design looks like it will mitigate that

[digger]

I think the runner longer will make more area under the curve without hurting the peak as it's more matched to the rest of the engine rpm capabilities .

I've seen Ported m30 heads flow 250+cfm which way more than any m20 and on par with s50b32 and the like so there's potential but there's more to it than airflow. A valvetrain that lifts 15mm would be nice

If you tell me a bunch of specs I can run some sims to see where it's at.

[george graves]

biggest thing i don't like about the m30 is that it doesn't rev past 6.5.
it just dies.

Well, that's 100% true, it hits a brick wall. But in an e30, you're moving fast enough to grab the next gear, thats not a big deal to me. I still vote for the m6x swap. It's totally not period correct, but it acts like an electric motor.