e34 running gear in e12

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ckn
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Joined: Thu Feb 06, 2020 11:04 pm
Location: PNW

e34 running gear in e12

Post by ckn »

Anything is possible with deep enough pockets, but I'm curious how much of an e34 running gear "fits" in an e12 chassis.

My '75 528 has been garaged for about a decade, so a ground-up restoration is likely what I would do. From taking a quick look around, purchasing a running e34 seems pretty cheap... which provides the possibility to go overboard and create a four wheel drive e12 from an e34 touring.

So my question boils down to: is this lunacy? The car is RHD, which perhaps makes it more challenging (not sure).

Thanks for any answers or insights in advance!
ckn
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Re: e34 running gear in e12

Post by ckn »

Some further reading on the e34 525xi and their relative rarity, the four wheel drive aspect seems like an extreme long shot, even before beginning to retro fit the front wheel drive bits in an e12.
tlake
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Re: e34 running gear in e12

Post by tlake »

ckn wrote: Fri Jan 08, 2021 2:55 am Some further reading on the e34 525xi and their relative rarity, the four wheel drive aspect seems like an extreme long shot, even before beginning to retro fit the front wheel drive bits in an e12.
Are you sure the awd e34 was even sold in Australia :?: Even so, there may be more rewarding/easier avenues worth trying, like an M30 3.5L swap. 8)
ckn
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Re: e34 running gear in e12

Post by ckn »

Yes true, most likely the 525xi was not sold in Australia.

Regarding 3.5L, I'm not even sure what engine is in the car right now... the block has 3.0/3.3 on the side, and also a Solex 4A1 carb... so not the factory engine/spec. 3.5L EFI would be fun, but perhaps not a big difference for all the work. I'd sooner convert the car to all-electric than a 3.5L EFI.
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Lock
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Re: e34 running gear in e12

Post by Lock »

For what its worth, my e12 will be mostly e34 underneath soon. Today it has e34 manual gearbox and engine management, also e34 power/heated seats. These were essentially bolt in parts.

Once the engine and rear end swap are complete, it will have:
e34 trailing arms, e34 LSD center in e28 case with e28 subframe, e28 block (thicker than e34 & has the right mount bosses) with e34 pistons, and other e34 bits I took from the e34 I had in my yard for a few months like mirror motors, cruise control system, headlights etc.

So you could buy a running e34 535i, and with a bit of effort drop the engine and gearbox straight in. For more effort but more fun get a 540i and drop the V8 in (or just go straight to LS).

Be interesting if you did convert it to electric though. I know they sell drop-in LS compatible electric motors, that, a gearbox and batteries and you'd be on your way.
1979 528i - M30B34 with 9.5:1 B35 pistons, 5-speed conversion G260/6, e28 rear subframe, e34 LSD 3.9:1, glass sunroof, e30 elec speedo, cruise control
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