M54B30 or M30B35?

General conversations about BMW E28s and the people who own them.
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adam_poll
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M54B30 or M30B35?

Post by adam_poll »

Hello, I am currently debating in my head which engine I should be swapping into my 1984 525i. Last year after finally getting the car on the road I quickly realized that the stock M30B25 was not enough for what I wanted to do in the car so I swapped in the M30B34 out of the old family 86 535i. This engine has treated me well literally since I was a baby over the past 400,000 km but as we all know the party is over above 5400 rpm with that motor. This car is primarily a fun track car so that last 1000 rpm is important, I want a motor that happily revs to redline and encourages you to do so rather than short shifting to get back into the power band.

I've settled on either an M30B35 or an M54B30. These engines seem awfully close to each other on paper, similar peak numbers, similar powerbands and I think similar weights. The older motor is a known swap, my clutch, lightened flywheel, transmission, shifter, driveshaft, cooling system all carry over the way they are. All that is necessary is some well documented changes to the wiring, engine mounts and some coolant re-routing. The newer M54B30 would require all of those things the M30B35 doesn't need changed and without a known recipe (use the front part of this driveshaft with the rear of this other driveshaft etc.) along with some improvements for track use such as oil pump modifications ($), possibly a better harmonic balancer ($$$) and I'd love to get rid if the dual mass flywheel ($$). The bonus of the newer drivetrain is that our local u-pull-it yards are littered with these things ($300) along with the odd manual transmission ($135) so if I pop one of these it's not a big deal to find another. The initial buy in price for the older motor is around $800-$1000 as I have to buy from a dismantler but the rest of the swap is cheaper.

I guess what I am really looking for is feedback from people who have driven an M30B35 swapped E28 in comparison with a manual 330i. What are they like as you rev them out? Are they playful from 4000 rpm up to redline or do things really fall off up top? The savings of the swap overall with the M30B35 would also free up some cash to swap in a cam and do some headwork so maybe that would balance things out.

Let me know what you think.

Thanks, Adam
Mike W.
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Re: M54B30 or M30B35?

Post by Mike W. »

Not exactly what you asked, but close. I had a E28 535i for 155K, yeah, the B34 isn't a B35, but still. Then I got a E36 328is. According to owners manuals it's a whopping 78 pounds lighter than the 535. Which is next to nothing. Seat of the pants the 2.8 pulls in 5th like the B34 did in 3rd with a 3.46 diff, the E36 having the rough equivalent of a 3.64. The quicker of the road tests for the E36 listed 1/4 mile times at 14.5. On a par with E28 M5s which were admittedly heavier than the more pedestrian versions, but did have a more aggressive diff ratio. And the M54B30 is rated at another 30HP than the 2.8 I've got. I'm a big M30 fan, I've put close to half a million miles on them between my wife and myself. But the M5X is a more than worthy successor. Go with the M54B30.

In the lightweight 525i it ought to be really fun. :D
adam_poll
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Re: M54B30 or M30B35?

Post by adam_poll »

Thanks Mike, I have driven an E36 325is in the past and I was really impressed with how even that motor pulled through to redline. I've put together a spreadsheet and I think I can do the the M30 swap for about $1500 CAD and the the M54 for around $2500-$3000 plus extra labor, that would include upgrades to the oil pump and getting rid if the stock flywheel.

Adam
athayer187
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Re: M54B30 or M30B35?

Post by athayer187 »

I always wanted to put an M54 into an E30.
mitch5
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Re: M54B30 or M30B35?

Post by mitch5 »

Something to consider is that swapping to an m54 will require also motor and trans mounts, some custom exhaust work, new ps lines, possibly a custom rad and a bunch of wiring. Not to mention i believe the m54 will require a bit more work on the ecu side compared to the m50 swaps yous see in e30s. M54 has dual vanos and that friggin disa valve to worry about too. In my opinion thats alot of work for not alot of power gain. B35's are also cheaper to rebuild, athough one could argue m50's have more aftermarket support.

I had an e46 330ci and while it was quicker than a stock e28, it didnt have the same torque feeling. i think the redline on that car was only 6500 but power would drop after 6k. I would say get a b35, stick a cam in it and do a standalone ecu. When i ran my stock b35 on megasquirt with headers i would redline it to 6500 rpm all day, and it picked up power in the process. im not sure where your located but b35s can be had for $300 if you find someone parting a car on cl.
tn535i
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Re: M54B30 or M30B35?

Post by tn535i »

If you could get an M54 with the six speed manual it would be worth all the trouble. It would need to come from a ZHP car if not mistaken and then you would also have the hotter cams. My son has a 330ci 6 speed ZHP and it's wonderful.
Cactus
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Re: M54B30 or M30B35?

Post by Cactus »

You could put a shrick cam in a b35 for a lot less money than an m54 swap. Get some headers, maybe a maf kit.
duggi
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Re: M54B30 or M30B35?

Post by duggi »

m54 all the way: DOHC, DISA, and Dual VANOS just make it a much more flexible than the m30 could ever be. I love the older SOHC engines, but in all honesty, you can't compare an m30 to an m54...the m54 is just superb.
Tiit
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Re: M54B30 or M30B35?

Post by Tiit »

As stated in the first post it's going to be primarily a track car. DISA, vanos and fancy electronics improve fuel efficiency and low rpm torque and do bugger all to increase top end power. I'd personally go with b35 + bigger cam and headers. Maybe even triple side draft carbs. Would be cheaper, easier and quicker to get it back on the road. I'd hate to have car apart for long periods of time to get custom parts fabricated and fiddling with electronics. Driving is so much more fun.
adam_poll
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Re: M54B30 or M30B35?

Post by adam_poll »

Well I'm glad we're coming to a consensus lol

I think I've got a pretty good handle on what both swaps will take to complete, M30B35's are getting thin on the ground here so I'm forced to buy one from a dismantler rather than just spending a fun day in the yard pulling one myself like I can with the newer motors. The big question marks on the newer engine are transmission mounts and driveshaft, I'm sure there are stock BMW parts that can likely fill both of those needs but it isn't common knowledge like it is for the E30 guys. The electronics aren't as difficult as they were before, you can get ECU's programmed with the EWS (fancy new key bs) and the body side of things deleted so that you can run these motors in the older cars, it really comes down to modifying a wiring harness to bring the two together.

Thanks for all the feedback, I should really find a used 330i for sale and go for a test drive, I'm sure they wouldn't mind me running it through the gears a few times to redline.

Adam
mitch5
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Re: M54B30 or M30B35?

Post by mitch5 »

im fairly certain someone sells m50 to e28 swap mounts, classic daily i believe, not sure if the m54 has the same mounting bosses. If you can really get m54 pullouts that cheap then i say go for it. Also i would suggest getting a 1 piece driveshaft made if you do the swap, i was able to get a steel one with rebuild able u-joints for $180 from a 4x4 shop.

And sidenote the disa valve does make a huge difference in low rpm torque, like 15 ft lbs. when mine went out it i felt a noticeable powerdrop. I would try to keep that functioning
Cactus
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Re: M54B30 or M30B35?

Post by Cactus »

Why not S50 or s52? Either of those might really simplify wiring.
adam_poll
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Re: M54B30 or M30B35?

Post by adam_poll »

Cactus wrote:Why not S50 or s52? Either of those might really simplify wiring.
I'd love to have an M motor of some sorts but I am on a budget, I think I'd go all the way up to an S54 if I were planning on spending that much. The U Pull yards here charge $285 CAD for a complete motor with accessories and E46's and E39's are showing up regularly so that is why I've focused on the M54B30 in particular, I also like the aluminum block for some weight savings.
mitch5 wrote:im fairly certain someone sells m50 to e28 swap mounts, classic daily i believe
You're right, I hadn't thought to check there yet but they show engine and transmission mounts (they don't list them for M54 but my research shows they will work). I was planning on E28goodies engine mounts if I went this way, Preacher's 5 is using them and it actually looks like the stock E36 transmission mount for his automatic bolted right up so that may not be an issue at all. http://www.mye28.com/viewtopic.php?f=7&t=148224

I'm basing a lot of my research on this thread for anyone else looking into this -https://www.r3vlimited.com/board/showth ... p?t=383897

Adam
kodachrome
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Re: M54B30 or M30B35?

Post by kodachrome »

I'm currently doing an M54B30 swap, well, with an actual mechanic doing most of it.

E28goodies engine and gearbox mounts seem to fit perfectly.
All wiring and EWS, rear cats tuning taken care of by Redline Motorsport - note we haven't started car yet but it's near plug and play.
Stock e28 radiator fits.
Stock M54 fan fits, shroud does not.

Still to solve
- RHD pedals.
- exhaust manifolds to clear rhd steering. Stock M54 and small 'tubular' M52 types don't fit. Trying e38 728i manifolds now.
- coolant fill reservoir placement.. Too close to DISA.
vinceg101
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Re: M54B30 or M30B35?

Post by vinceg101 »

Not really related, but I've been dreaming of having a manual M54B30 in an E34 Touring.
Just an all-around daily kind of cart, not a sport car.

I'm not interested in installing one, just having one :laugh:

I have an E39 530iA Sport and the driveline is quite impressive. The M54B30 is a really nice motor.
Mike W.
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Re: M54B30 or M30B35?

Post by Mike W. »

vinceg101 wrote: Apr 01, 2021 7:58 PM Not really related, but I've been dreaming of having a manual M54B30 in an E34 Touring.
Just an all-around daily kind of cart, not a sport car.

I'm not interested in installing one, just having one :laugh:

I have an E39 530iA Sport and the driveline is quite impressive. The M54B30 is a really nice motor.
In an E34 touring? Why not in an E39 touring? Now that with the 40+ HP more than my wife's 525it would make a nice daily.
vinceg101
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Re: M54B30 or M30B35?

Post by vinceg101 »

Mike W. wrote: Apr 01, 2021 9:46 PM
vinceg101 wrote: Apr 01, 2021 7:58 PM Not really related, but I've been dreaming of having a manual M54B30 in an E34 Touring.
Just an all-around daily kind of cart, not a sport car.

I'm not interested in installing one, just having one :laugh:

I have an E39 530iA Sport and the driveline is quite impressive. The M54B30 is a really nice motor.
In an E34 touring? Why not in an E39 touring? Now that with the 40+ HP more than my wife's 525it would make a nice daily.
It's a personal thing, of the two Touring bodies, I prefer the E34 much more than the E39.
e12euro
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Re: M54B30 or M30B35?

Post by e12euro »

A more even match for the M54B30, than the stock M30B35, would be the 260 hp Alpina B10 motor used in the e34. As was said above with a triple carb set up, Schrick, headers and high compression ratio the old M30 can deliver, without the conversion hassles. The final Group A 635CSis had 310 hp from their M30B34s. :cool:

Group A BMW 635CSi
LeiseyJr
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Re: M54B30 or M30B35?

Post by LeiseyJr »

IMO, just put a cam and a chip in your current motor or rebuild it if you want to. It will give it that 1000rpm and be fun. Without redesigning the whole car and basically be drop in.

If you’re making a dedicated trackcar, then M54 is the move. However I still think I’m in the s50 bandwagon, but prices for those are getting crazy expensive. So I can see the m54 appeal.

My only complaint with the m30 is the over-oiling in the head, but with oil restrictors. That can be remedied or just a simple catch can. If I were to redo anything again, when my timing chain went. I wouldn't have done the 10:1.

I still think a 8:1 M30B34 and a chip is the best bang for buck and the least amount of work, while maintaining all stock stuff.

M30B35 is an option too, but having to swap to M1.3 and specifically the motor mount arm always put me off. I did swap too M1.3 at one point but went back to M1.0 due to tune related things for the high comp.

If you want a m54 and have a fun street car for not a lot of hassle just get an e46 330i.
Last edited by LeiseyJr on Apr 10, 2021 12:17 AM, edited 2 times in total.
wkohler
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Re: M54B30 or M30B35?

Post by wkohler »

Mike W. wrote: Apr 01, 2021 9:46 PM
vinceg101 wrote: Apr 01, 2021 7:58 PM Not really related, but I've been dreaming of having a manual M54B30 in an E34 Touring.
Just an all-around daily kind of cart, not a sport car.

I'm not interested in installing one, just having one :laugh:

I have an E39 530iA Sport and the driveline is quite impressive. The M54B30 is a really nice motor.
In an E34 touring? Why not in an E39 touring? Now that with the 40+ HP more than my wife's 525it would make a nice daily.
That's what's in mine, with a manual. Started life as a 525it with a manual. It's pretty good. I'd dare say that 530i 5-speed is the best E39, and I say that owning an M5.
vinceg101 wrote: Apr 02, 2021 10:58 AM
Mike W. wrote: Apr 01, 2021 9:46 PM
vinceg101 wrote: Apr 01, 2021 7:58 PM Not really related, but I've been dreaming of having a manual M54B30 in an E34 Touring.
Just an all-around daily kind of cart, not a sport car.

I'm not interested in installing one, just having one :laugh:

I have an E39 530iA Sport and the driveline is quite impressive. The M54B30 is a really nice motor.
In an E34 touring? Why not in an E39 touring? Now that with the 40+ HP more than my wife's 525it would make a nice daily.
It's a personal thing, of the two Touring bodies, I prefer the E34 much more than the E39.
Using the two cars, the touring part of the E39 is much better than the touring part of the E34, it has more room, they integrated the now black dog net and cargo cover and put a really nifty place to store it when you've got the seats down, something, something, it doesn't have a horrendously stupid sunroof and the interior doesn't rattle itself to death and fall apart. I have plenty of E39 complaints, but I am pretty happy with the touring.

For a while after getting the E39, I was bummed when nice E34s started popping up again (since you know, they don't when you're actually looking), but now I'm largely over it and appreciate the E39. Of course, none of these cars are E28s, which are objectively better in every way, but when you have to compare inferior cars...
adam_poll
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Re: M54B30 or M30B35?

Post by adam_poll »

So, seeing as this has jumped back up almost 2 years from my initial post I guess I should give an update. I'm still rocking the M30B34 in the 525i and I'm okay with that, I never leave the track wishing for more power, just more grip it seems. Maybe part of that is the tracks I have been running at (Mosport) and that will hopefully change once the border re-opens and I can venture to some fun circuits stateside.

I did chase an oil leak last year and in that process pulled the head as I had oil seeping from the headgasket in the back right corner. At some point in 2019 I lucked upon an E34 535i in our U-pull yard that had had the head gone through recently due to a broken rocker. At the time pulling the hole motor wasn't an option but the head was, for $75 (CAD!) I got a head with all new Febi rockers with a cam in perfect shape along with the intake manifold as the girl at the counter thought it was part of the head lol. So, when I had the head off I swapped over the cam and new rockers into my B34 head and that really made a nice improvement, not life changing but it definitely pulls harder to readline. I've also done a set of Schmiedman headers to a single 2.5" mandrel bent exhaust that I put together so I'm sure that helps a bit over the cobbled together walker garbage with a cherry bomb the car came with!

Right now the ideal plan would be to pull the motor over a winter, go with higher compression pistons in the B34 block and the M30B35 head and intake with a more aggressive cam. When I pop the hood an M30 is what I want to see and I have thoughts of vintage racing with the car down the road so that will make things easier than explaining a much more modern motor. 1982 Group A tribute someday.

For now though addressing the oiling issues is number one on the list, I'd like to move to more aggressive tires than the RS-4's I've been running but I won't do that and just hope for the best. Accusumps come to mind along with crank scrapers (but it sounds like the good ones are not easy to get). I am curious what all the Group A 635CSi (and the older coupes as well) do as they have to address this, from poking around the net looking at under hood images a lot of them run some sort of air oil separator tank that drains back to the sump (they seem to sit where our batteries sit). I've also seen one of those cars with an accusump as well. Maybe dry sump is common for those but I honestly haven't seen any evidence of it from the pics I have seen (external oil pumps tucked up under the intake). Both the S14 and S38 run air oil separators as well rather then the crude setup on our M30's. Based on that if I can get the IJ Crank scraper (which include trap doors to keep oil flowing down into the pan and not up out of it on left corners) along with an air oil separator to get any oil that does make it out of the valve cover back into the sump I wonder if that will be enough? I'm not convinced that restricting the oil flow into the head is a good idea for a car that still sees time on the street and gets driven to the track at low rpm.

Well, that was long, thanks for the pm LeiseyJr if you made it this far!
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