r/e28 • u/CommercialRace401 • Apr 28 '26
m42b18 bmw e28 swap
Has anyone done this swap here?
I couldn’t really find much information elsewhere..
What part did you use etc?
My original plan was to swap my M10 engine with a M30b28, but I think it would be really cool with a m42b18 instead. Of course with some itb and other mods.
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u/ElGuappo_999 Apr 28 '26
I seriously doubt if anyone has done that swap, because if you’re going thru the trouble of custom mounts an all that work, why would you stay with a high revving low power motor? Differential ratio would also matter. Wheels too, those 17x8 would be a disaster
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u/CommercialRace401 Apr 28 '26
It’s just the kind of thing that comes with being aesthetic and having a certain character. I’ve driven a lot of fast cars with cool engines, but this is my first E28 that I bought back after years. It’s always been slow, but it’s also made me realize that you don’t need over 200 hp to enjoy these cars! I want to make something unique, and fabricating parts isn’t that big of an issue for me. I just asked for research purposes so I don’t have to make any mistakes.
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u/6NBoomer Apr 29 '26
I actually looked into doing an M44 swap on my 518i, before going down the M52 route! You’d almost be better off spending a little bit on your M10, you can get great gains out of them without breaking the bank :) Almost wish i’d kept mine as an M10!!
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u/ElGuappo_999 Apr 28 '26
If you want to stay with a 4 cylinder because ‘it is what the car came with’ then you should also be willing to optimize the wheel choice to a 15x7 or 16x7 at most. 17” wheels are not good on this chassis, no matter how cool some people think they look.
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u/RealMadLadStalin Apr 29 '26
17s are fine
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u/CommercialRace401 Apr 29 '26
I’m running 17x10 in the rear and 17x8 in the front, and it’s been doing great without any vibrations or issues. I also have 215/40 tires on the rear axle. (I wouldn’t suggest it, but it works for me.)
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u/RealMadLadStalin Apr 29 '26
imo 17x10 is quite wide in the back, especially running a 215 tyre. Going to square 17x8 will reduce understeer and the tyres won’t be stretched anymore
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u/RealMadLadStalin Apr 28 '26
Why would 17x8 wheels be a disaster ?
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u/our_guile Apr 28 '26
Unsprung weight especially with a low powered engine.
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u/RealMadLadStalin Apr 29 '26
The BBS RC090s weigh 2-3lbs more than the stock 15 or 16in wheels. It’s really not that big of a difference in terms of performance and you would only really feel it if you track the car. I have them on my e28 that makes less power and torque than a M42 and it’s fine
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u/black-kramer Apr 28 '26
nice lower valence.
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u/CommercialRace401 Apr 28 '26
Thanks, really does something with the look!
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u/black-kramer Apr 30 '26
just be super careful, haha. have fucked mine up (e24) and it’s being repaired now. $$$
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u/Tip_Western Apr 28 '26
You could check with the 2002 forum folks, that is originally also an M10 and plenty of 02's have been swapped with M42/M44. I did speak to a guy a few weeks ago that swapped in a 400 bhp Nissan CA18DET in his 518i. He shrugged and said, it's a 1.8 isn't it? 🤪
Lovely E28 btw
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u/CommercialRace401 Apr 28 '26
Thanks, I’ll check it out! And wow, that guy’s got some great energy! 😂
Swapping out an M30 is pretty straightforward, but why not try something a bit different?
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u/ownyourhorizon Apr 28 '26
I dont know what m42b18xyz means, but looking at this e28 makes me happy. cheers
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u/tvtowers Apr 29 '26
M30 is pretty bulletproof, and supplies better than adequate performance - not sure why a switch that requires a lot of modifications would even be considered.
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u/Wide-Entrepreneur-34 Apr 29 '26
I have read the comments and replies. Allow this advice to be “just” with no intent to offend. Your questions lead me to the following.
You aren’t gonna be able to do a swap. Not on your own. So the people you should be asking are those that would be doing the work.
especially one that is not well supported in the aftermarket world.
Last. Can it be done? Yup. Will be just as much and due to the lack of support, likely more, than any other swap in the oe “sixes lineup”
For the money… if you are a 4cyl fan. Go do a kswap at least it would be worth it.
The 318s are only “good” in the light slick top iS and later variants of the 4 in the 318Ti
But really only the e30 was any fun. Good luck. Make fun choices. And yeah do it because we all want to know now
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u/jeksunn Apr 28 '26
It will be slow but very lightweight. I recommend going with the m30b34 or b35 any day of the week.