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M50/S50/S52 E30 Conversion

Discussion in 'E30 (1984-1993)' started by MGarrison, Jan 14, 2009.

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    MGarrison

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    poke around on realoem and you can occasionally answer your own parts questions -

    http://www.realoem.com/bmw/showparts.do?model=1113&mospid=47309&btnr=23_0380&hg=23&fg=10

    A lot of various BMW model motor mounts are probably relatively similar; for instance some six-series motor mounts work fine for E30's; you have to cut off one nub, and it's a smidge taller, but its a harder durometer rubber than the stock E30 mount. You need answers from someone who's had the various motor mounts in hand for comparison.

    Zionsville autosport probably has the most comprehensive info and stuff for a conversion. Either buy this (E30 Conversion manual on CD) and get answers to all your questions (ya, I know, it costs waaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaay too much, why don't they give it away free, you couldn't possibly afford it, it's not worth the money, yadda-yadda-yadda-yadda-yadda) or ask around and find someone who's already bought it and would be willing to answer your questions so you can continue to source whatever parts you need as you progress through the project. Unless you find someone who can give you the answers you need and know it won't be wrong, I suggest buying parts from someplace that will let you return and exchange them just in case you do end up with motor mounts or transmission mounts or crossmembers or whatever that won't fit or work.

    All the info might well be out there on the 'net, but you may just have to slog through 60-page threads to get it if that's your only alternative. Glad you're making progress, keep chipping away at it and you'll get there.
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    mooseheadm5

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    Typing here cause it thinks I need 10 of my own characters to post.
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    az3579

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    Thanks for that, though the diagram says Getrag 280. But at least now I know what a transmission crossmember is. :)

    According to mostly everyone in the r3v thread that bought it, they all say that the Project Orca CD is worse than useless, and even if it wasn't, I still wouldn't spend $100 on information that should be free (and is freely available online for that matter).



    Thanks, that answers the "why" (though I didn't think to ask it).


    I was really trying to avoid having to mod anything by grinding or shaving, but if there's no other way, then I'll have to get someone else to do it because I will screw it up. As far as the motor mount goes, is there something that is a little softer? It being a daily driver makes it a little annoying to have all of those extra vibrations, but is durability an issue with a softer mount? Perhaps an M mount will do well for an M engine. I do hear about potential clearance issues with the booster though, so I might take your scenario with having a harder mount on the left and a softer one on the right so it would shift away a little from the booster.



    So I take it that using the M20 everything (which I already have) and just modfiying the crossmember and grinding the fins on the oil pan is a better idea than just buying another set of everything (gearbox, flywheel, etc. etc.)? I didn't think E36 trannies were that expensive, but it does add up after a while.


    Thanks for all the tips so far!
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    mooseheadm5

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    I would do M20 everything because of the price and the fact that E36 transmissions are pretty notchy. The clutch, trans, flywheel, release bearing, etc would really add up if you did M50 stuff. That, and if you can track down a light M20 flywheel, it will be cheaper than a light M50 flywheel. I have a 13 pounder in the ti from an M20. You can easily find a stock E30 325i flywheel that is much cheaper than any aftermarket lightweight single mass flywheel from an M50. Now, you can mate an M20 flywheel to an M50 trans, but there may be release bearing length issues (like I had.)
    Anyhow, nothing wrong with a hard driver's side engine mount and a softer passenger side mount. The intake will be a very close to the brake booster. You can trim the decorative plastic fins to help. This is the reason why people will install ix boosters (since they are smaller in diameter) or they will slot the holes that hold the booster and slide it over a centimeter or so. The second option is much cheaper, but you have to do some fiddling to see how much to move things over. I have not explored that option fully, but you ought to search on that one (maybe slot + booster in the search function over at r3v.)

    Basically, it may take a bit of effort if you use stock stuff but to me, time and effort are better than spending money.
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    az3579

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    Normally I'd agree with you on the time and effort part, but once this project gets going, it's going to be completed in a weekend. I don't have a spare car to use, so Chris was kind enough to let me borrow the E28, but I don't want to be driving around in his car for a long time, which is why I'm only prepared to drive it for a week or two. I want it 80% + done in a single weekend, and it's do-able.

    M20 stuff it will be then. I think I saw someone selling the modified crossmember on r3v, so I'll track that down, or ask my installer if he is able to mod it. I will definitely use an ix brake booster then, since it's smaller and doesn't require modification to the firewall. It looks "dual chambered" - does that help in any way over the stock booster braking-power-assist-wise? I think one of the "parts lists" that I saw for the swap said to use an E34 M5 master cylinder if used in conjunction with the ix booster.
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    mooseheadm5

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    You mean E34 M5 master cylinder, I think. I see what your plans are, and I think they a bit optomistic, but nothing wrong with expecting the best (so long as you plan for the worst.) Anyhow, that guy sells the cross member and I believe he also sells the lightly modified shifter parts you will need, so definitely buy those. Unless your guy can TIG weld aluminum, he can't make the necessary changes.
    Also, if the ix booster is too $$$ look into the E32/34 V8 booster option. I think some people have had success with those, but don't know for sure. They are pretty plentiful in junkyards right now. You may even get the master with it (though I don't know if you can use it.) Yes, I believe that there is more boost to the brakes with the dual chamber setup.

    z31maniac guest

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    mattdk318i on R3V, I'm using his modded shift rod selector/shift carrier/trans mount

    Good luck, but I can assure, I've been researching parts/forums everything for months. And I can tell you with CERTAINTY, YOU WILL RUN INTO UNEXPECTED PROBLEMS, have INCORRECT PARTS SENT TO YOU, etc.

    Do NOT bank on getting it done in one weekend. I'm just tellingyou , there is a TON of work. I'm not trying to be a downer, you just will run into issues, you just will.

    I'm chasing down a no fuel issue now. I suspect my DME relay or DME is bad or my fuel pump relay. I'm going to do more troubleshooting tomorrow.
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    az3579

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    I know, I know, but I don't really have a choice, so it's a must to get it done ASAF'nP. That's why I'm prepared to drive the loaner for a week or two instead of just a weekend (if he'll let me have it that long - lol).

    BTW, what parts did you use?


    I've got the E34 pan arriving on Tuesday and I'm ordering an ix booster tonight or tomorrow. I'll probably end up with the E34 brake master cylinder as well if I have enough cash.
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    mooseheadm5

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    z31- just jump out the main and fuel pump relays. Do you have a pre-1/95 DME? If not you have an EWS issue (that goes for both of you.) Do you have spark (have you checked?) Does it run on carb cleaner or no? I might be able to save you a bit of diagnostic work. Lemme know.

    B- do you already have the wiring harness adaptor made?

    z31maniac guest

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    If your master is working fine, no need to replace it. I went with the TreeHouse Racing Booster, bolts right up, fits perfect and they test it before it leaves the shop. Is it expensive? Yes. But I think it's worth it.

    And if the E34 M5 master cylinder has a bigger bore you're going to end up with a stiffer pedal.

    Ok here is EXACTLY what I've used:

    TreeHouse Racing Booster (Zionsville Automotive also sells a modded one)
    TreeHouse Racing Harness adapter (bought used from a friend)
    E28 M5 mounts (ended up having to flip them 180° because of the TMS reinforcement kit on the subframe)
    E34 pan/pickup/dipstick (you knew this one :D)
    E34 Throttle cable

    G260 (E30 6 cylinder trans) with mattdk318i modded trans mount/shift selector/shifter carrier (I stuck with the 260 so I wouldn't have to change the rear diff or replace my recently installed rebuilt driveshaft right before the M20 popped.)

    M20 flywheel/starter/clutch (The starter has to match the flywheel, period.) I had a local shop build me a heavy duty clutch and lighten the flywheel. Lightening the M20 flywheel is done by removing the material on the back, which is precisely what interferes with the E34 pan. You kill two birds with one stone. And I got the entire setup (flywheel lightened and resurfaced, clutch/pp/to bearing/pilot bearing/alignment tool) for under $300 from a reputable local shop, can't beat that.

    Red label 413 DME

    E36 OBD-I 5 speed harness (good luck, you will have a much easier time either finding an Auto harness or an E34 harness, you can just trim the extra auto connections off)

    Late E30 radiator and overflow tank (you can also use an S54 MCoupe radiator with stock E30 mounting hardware for a cheaper 3 row upgrade than an aluminum radiator), E36 radiator hoses, use the E36 spider hose, and use the E30 head-to-heater core hose. You can run an adapter fitting to connect the E36 spider hose to the hose coming off of the E30 reservoir.

    z31maniac guest

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    I've got a red label 413. I've got a thread going on R3V and I think it's the fuel pump relay. I'm getting a slight hum/vibration on the intake manifold with the key on and I'm told that is the ICV and so that means the DME IS getting power.

    I haven't checked spark yet (I don't have a multimeter), but I wanted to solve fuel then move on. But if the DME is getting power, it has to be the Fuel Pump relay, I think?
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    mooseheadm5

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    The DME is def. getting power if you have humming. You can't test for spark with a multimeter unless you want to kill it and hurt yourself. Best way is to pull the MAF and lightly spritz the intake with carb cleaner (and nothing else.) Just jump out the fuel pump relay- red wire to green/violet wire. You should hear your fuel pump run if you do so. If you do and the car still won't start, you may have other issues. If you don't you need to check the fuel pump fuse and then wiring. Go to Harbor Freight or Northern tool and plunk down 5 bucks for a multimeter.
    1 people like this.

    z31maniac guest

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    I was thinking checking the harness, not after the coil, as a means of checking if the DME is sending the signal to the coil?

    I know checking the coil is tens of thousands of Volts!
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    mooseheadm5

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    I have read of people having problems with the THR boosters leaking.
    You can buy a 323i flywheel which will likely not interfere with the oil pan. I know my super secret OEM lightweight M20 flywheel works perfectly on wifey's 325ti- no machining necessary.

    B- you need a 3.73 diff? I got one you can have cheap. That 2.93 with your G260 will give good gas mileage, but you will lose a bit of go off the line.

    A larger bore master with more brake boost from a dual diaphragm booster is a good match. That is why some people do it.
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    mooseheadm5

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    A multimeter won't necessarily catch the ground pulse from the DME to check spark. You can pull the coil pack and insert a spare plug with the body of the plug grounded. You ought to see a fat blue spark while cranking. The reason I say you should check spark is that it is possible for the crank position sensor to be hooked up wrong (i.e swapped with the cam position sensor) or it is possible that it is bad. Without crank signal, it wouldn't matter how much fuel you have- it would not run. To that end, does your tach move when you crank the car?

    z31maniac guest

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    I have read of problems with basically every part you can imagine. But you only hear the complainers, not the tons of people who are happy with it. And I still understand there are many more people that are happy with THR than not. And they warranty their product.

    Although getting the booster off is a major PITA!

    No point, to me at least, tracking down a 323 flywheel. Just have your stock M20 flywheel lightened and resurfaced. Done.

    Oh and Botond, here are two other little goodies that have ended up on my swap. TMS Shorties with a custom downpipe into a V-band (bought from the same friend who sold me the motor mounts and THR adapter, races in BMWCCA)

    [IMG]

    Massive Brakes, 280mm street kit with Racing brake corrado rotor and Dynapro caliper.

    [IMG]

    [IMG]


    Here is a link to my main build thread on R3V, there are few more in the Members ride section that cover some of the suspension stuff we did. Feel free to ask me about anything I haven't addressed.

    http://www.r3vlimited.com/board/showthread.php?t=145865

    I did get a 3.73 just bolted up. I had a 4.10 and sold it. I knew that would be too much with G260 and S52.

    Oh and

    z31maniac guest

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    Ahhhhh, good call.

    Didn't pay attention to the tach, guess I could run outside and check. But it is a new Crank sensor and I double checked all the wiring against the wire colors on the E30 DOHC WIKI page. If I remember too, the Crank and Cam sensors have different plugs as well.
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    mooseheadm5

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    Icouldn't remember if they were keyed different. I know on the earlier (M20/30/70) engines you could switch them.

    I was asking Botond (aka B or az4o82301754) if he needed a diff.

    Also, there is a 323i flywheel for sale on the mye28 forum.
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    az3579

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    To answer your questions Paul:

    No, I do not have the wiring harness adapter made yet.
    I have the 2.93 diff and plan on keeping it because 1) it still works, 2) it's an LSD, and 3) I will be daily driving this beast so gas mileage is sort of important. I want to get decent mileage when I'm not hammering it. Besides, as nice as a high-revving S50 sounds, it gets intrusive when taking long road trips and it's revving 5-grand at the speed I'm doing. lol



    So, based on what has been said so far, the other definite things to order are the E34 throttle cable and the E34 master cylinder. I don't mind a stiffer pedal, and I quite like the control it gives me. I don't brake hard often, but when I do, I hate a soft pedal, so that extra firmness will well suit my driving style. (Gawd I hate the brakes in my mom's Nissan Sentra -- soft as hell even after bleeding)


    So on my list to order for this week:
    325ix brake booster (Might be able to score one - hard to find)
    E34 throttle cable

    z31maniac guest

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    Probably wouldn't be a bad idea either to see if I could rent an OBD-I code reader from a parts house this weekend as well.

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