M30B35 Swap

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santiagoe12
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M30B35 Swap

Post by santiagoe12 »

Hi guys,

I am planning a M30B35 (´91 euro e32) swap in my M20 e12, and I have come across a few doubts as I am not familiar with M30s.

I understand that I sould use an e12 oil sump and pump. About the pump, should I use the B35 main body and a e12 pick up tube? I have read here and other forums about some oil pressure issues but was unclear. I have a 528I sump and pump for this aspects of the swap.

At the time I´m only cleaning and sourcing parts, and plan to refresh everything in this engine. But for a future stage, maybe next year if this coronavirus allow us, I plan to add a turbo system. In order to drop a few points the actual compression ratio (maybe form 9:1 to 8,6:1), I would like to use a thicker MLS head gasket. Can someone confirm the std head gasket thickness? Also, I searched the forum but didn´t find much info about turbos and would like to know of experiences with cylinder head bolts. This isn´t a race car, it´s a daily driver and will spend most of the time in the city under 3k rpm. Turbo pressure won´t be beyond 0.6 bar. Will the standard head bolts hold up fine? I was told from "experts" that intercooler wasn´t necessary for my goals, but I would like to be safe and keep intake temps as low as possible with a front mounted intercooler.

Other thing that I would like to know, is if I can use the e32 radiator. I only took a few measures and it seems it would fit. I know that you probably would recommend me to use the e12 radiator, but understand that I am in south america and it is a PITA to get parts. This radiator was included in the engine so I would save around 350 $ if I can use it.

Well, thats it for now. Will upload a few pics as soon as I can.

And sorry for so many questions in a strange english!! :roll: :roll:

Regards

Santiago
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keehn
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Re: M30B35 Swap

Post by keehn »

Santiago,

The E12 oil pump and pickup tube are integrated into a singular unit as shown below.

Image

Image

I'm not sure about the head gasket thickness, but I would ask the MLS vendor to ensure their gasket will fit your application. As for head bolts, I would HIGHLY recommend ARP head studs. The OEM bolts are reusable, as they do not stretch like a TTY bolt. That said, if I was in your shoes, I would not trust OEM in this situation.

I'm not sure about using an E32 radiator but you CAN use an E28 radiator. I have seen all-aluminum E28 radiators for sale. However, since E32's did come with the M30 as an option, the E28 MIGHT be an interchange part. I would suggest you check out www.realoem.com and look up both models to see if they use the same radiator.

And yes! Please post pics when you can; We always enjoy seeing fellow Fivers cars :D

Mike
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Lock
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Re: M30B35 Swap

Post by Lock »

The reason for swapping the oil pump/pickup is because the e34/e32 sumps are different to fit the subframe, and you'll need to transfer your e12 sump and pickup, they will swap between blocks just fine. I think it's covered in our first fives FAQ on engine swaps.

Looking at my e34, which is similar to the e32, the e32 radiator is physically about the same size but won't mount. If you are able to fabricate up your own mounts you could make it fit.

As Mike said, the e28 radiator also fits with a few minor mods, either the standard version or aftermarket all aluminum radiator.
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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keehn
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Re: M30B35 Swap

Post by keehn »

Lock, thank you for the clarification; I was not thinking about differing subframes.

Heh, I'm waiting for someone to ask how to fit an LS engine into an E12...seems to be the most popular engine swap in vehicles in general :lol:

Mike
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528i-1981
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Re: M30B35 Swap

Post by 528i-1981 »

(oo=00=oo) Eric
1981 528i Manual
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keehn
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Re: M30B35 Swap

Post by keehn »

528i-1981 wrote: Wed Apr 01, 2020 6:52 am https://grassrootsmotorsports.com/forum ... 482/page1/

LQ4-swapped E12.
SMH...... :roll:

If one were to go crazy and drop in another engine in an E12, they should pick the BMW M73 V-12. Naturally aspirated, it produces 322 HP and 361 ft lb of torque. Swapping in M engines is almost the "LS swap" for the BMW world; I would consider a V-12 swap far more interesting and unique.

Mike
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Re: M30B35 Swap

Post by canada karl »

How easy is it to find an M73 V12 at an auction auction? What years were they made. How hard would it be to do the actual swap? I'm thinking everything else on the E12 would have to be upgraded to handle the power. Would Getrag 265 5 speed bolt up to it?
1976 530i. BMW 59 Triumph TR3A(rolling resto). 67 Triumph TR4A(salvageable). 86 900S Winter car
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528i-1981
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Re: M30B35 Swap

Post by 528i-1981 »

I've read of M70/73 V12 swaps into E34s and E39s, and even an E30, but never an E12. Do it Mike! I wouldn't want to do the plug changes, but it would look great!
(oo=00=oo) Eric
1981 528i Manual
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keehn
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Re: M30B35 Swap

Post by keehn »

LOL! :lol:

I would need to find another E12 in order to do a crazy M73 swap. If I "were" to do one, I would opt for the 6-speed getrag in the E46's. No doubt quite of a bit of the engine bay would need to be chopped/modified in order to house that massive engine! Plus, the final drive and subframes/suspensions would all need modification as well.

...I just couldn't bring myself to do that to Eleanor though, hence the need for a second E12. I'm trying to keep her as much stock and period-correct as possible. My wife and I are thinking of moving into a larger house and garage likely next year, and a car lift will be my first upgrade. Perhaps at that time I just might tackle a FrankenBimmer project :wink:

Mike
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CabbageFumes
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Re: M30B35 Swap

Post by CabbageFumes »

A few clarifications:
santiagoe12 wrote: Thu Mar 26, 2020 12:18 pm
I understand that I sould use an e12 oil sump and pump. About the pump, should I use the B35 main body and a e12 pick up tube? I have read here and other forums about some oil pressure issues but was unclear. I have a 528I sump and pump for this aspects of the swap.
Use the pump housing that came with the B35, along with the sump and pump pickup from the 528i. The pickup will be a direct replacement to the B35 style pump pickup. You also need to use the smaller B35 pump sprocket and chain.

In order to drop a few points the actual compression ratio (maybe form 9:1 to 8,6:1), I would like to use a thicker MLS head gasket. Can someone confirm the std head gasket thickness?
1.5mm
Also, I searched the forum but didn´t find much info about turbos and would like to know of experiences with cylinder head bolts. This isn´t a race car, it´s a daily driver and will spend most of the time in the city under 3k rpm. Turbo pressure won´t be beyond 0.6 bar. Will the standard head bolts hold up fine?
No need for anything beyond OEM head bolts for what you describe. The E32 745i used OEM, so can you.
I was told from "experts" that intercooler wasn´t necessary for my goals, but I would like to be safe and keep intake temps as low as possible with a front mounted intercooler.
Nice to have, but not required for your application unless you drive it harder than you describe.
Other thing that I would like to know, is if I can use the e32 radiator. I only took a few measures and it seems it would fit. I know that you probably would recommend me to use the e12 radiator, but understand that I am in south america and it is a PITA to get parts. This radiator was included in the engine so I would save around 350 $ if I can use it.
The way it mounts is very different. Unless you want to fabricate mounts, an E28 radiator is a better fit, but even this one will need a few holes drilled in the core support.
Well, thats it for now. Will upload a few pics as soon as I can.

And sorry for so many questions in a strange english!! :roll: :roll:

Regards

Santiago
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santiagoe12
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Location: Montevideo, Uruguay

Re: M30B35 Swap

Post by santiagoe12 »

Hey guys,

Thanks all for your input, I really appreciate your help on this.

The oil pump issue is understood, thanks!!!

About the head bolts, It seems there are different ideas.
As Cabbage said, 745 used OEM bolts, I checked realoem and it uses the same PN as a common 735. It is true that ARP studs would surely provide an extra insurance, but it also would cost me an extra 280 $. I can get OEM new bolts here for 40$ so I think I will use OEM. Plus I would like to replace rod bolts, parts list keeps getting longer and I have to keep costs down.
To be truth, I´m getting too exited on that part of the build and I realise there are many things to solve before that.
About the radiator, wouldn´t mind to fabricate mounts, thats the part that I most enjoy. I will try to fit it (if it fits, will be a tight fit) and let you guys know.

Here are some pics, the old guy waiting for a new heart:

Image

Image

This engine looks like it had nearly zero manteinance. Huge oil leak from valve cover, nuts were loose and gaskets looks to be factory items. Only manteinance that looks to have been recently was a new water pump, and I believe that flywheel and clutch were replaced. I understand e32 735 only had dual mass flywheel, am I correct? This one has a single mass flywheel.
The good thing is that I can see clean water passages, compression test made it to 160-170psi all cylinders, no scoring on cylinder bores and pretty clean inside. Hope it won´t need big machinist work on the alternative group.

Image

Loose banjo bolt on the left, learned in this same site that is common between M30s. No significant wear in cam lobes, hope cam journals and lifters are ok too.

Image

Headgasket was wasted. Seems like this was the reason the car was parked for several years. Strange is that water entering cylinder bores tends to clean the top of the pistons, but this is not the case.

Well, I don´t have much time at home so I am taking parts to my work and use my spare time, starting with the alternator:

Image
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