Well that certainly sounds like it was an experience- bummer about the engine and the early ending in general. Colorado looks like a fun event and comes highly recommended, even by people who have to tow a really long way to get to it.
My move would be to look for partouts and hope for a "nobody wants a 4 cylinder" sort of deal. I think the M42 was more common in e36s, which are also closer to the cheap car/partout sweet spot.
That sucks. M42s around here used to be plentiful but nowadays everyone wants $600 for them. That's m50/m52 territory in my mind. I wouldn't waste time with the m20.
Honestly, I'm not sure that the difference between a $500 engine or a $1,500 is that big a deal either way. My bigger concern about swapping to a 6 cylinder isn't the expense as much as the time and effort. Certainly a $250 known-good M42 that I could just drop in sounds like the way to go, but I'm not optimistic about finding such a thing. Where do you guys shop for engines? Craigslist/FB marketplace? Not finding anything promising locally. There's things on ebay, but the "cheap" ones are $1,500+ shipped. https://www.ebay.com/itm/124948412058?hash=item1d1781769a:g:VPAAAOSwkcFfwUcV M42s don't seem any cheaper than M52s on ebay.
For an E36 M42, I'd have to swap the ECU and find an E36 engine harness. That seems like a lot of the work I'd need to do to swap to a 6-cylinder. I wouldn't have to deal with the exhaust or drivetrain or cooling, though. Also, I assume an E36 M42 would also put me in O2WD, but once again, I guess I don't care about that.
I'm happy to spend more if it were known-good. Maybe something that I have good reason to think will actually get me through a whole rally this time. I really don't want to spend $250 and swap in an E36 M42 only to find out it's not going to work, especially if I could spend a little more and get something that's more likely to work.
In reply to Berck :
You're in L2wd as long as the engine is 2500cc or less and came in "the same model range" which there's a pretty good history of "any 3 series" meeting the intent of. Swap away if the engine fits those parameters. The interchangeability would make the newer M42 less appealing then.
I'd be looking on car-part, craigslist, and facebook, and especially posting in any local groups where somebody might have something laying around.
Thanks. I'm not finding anything promising on any of them, though car-parts makes you search by model which means that searching for swapable engines is tricky.
Also, if anyone has reasonable ideas on reliability, I'm a lot more keen on that than torque curves:) Of course, BMW people claim that the M42 is reliable, but I think that German car owner's perception of reliability is many orders of magnitude off from what Miata people consider to be reliable:) To be fair: I have no idea what was done to this thing before I got it. I suspect it was chipped, maybe that was done poorly. And sitting for 5 years does sound like the kind of thing that might result in a clogged fuel injector.
Bummer, that's a new one as far as M42s go - definitely don't recall seeing that kind of failure. I'll be the one to call M42s reliable, as I ran one for 5-6 seasons and a half-dozen stage rallies, including smashing the oil pan (which did no harm to the engine). I just put another one in my project e30. That said, they're certainly not as "available" in e30 spec as they used to be. However, you may want to double-check the forums. Maybe I'm wrong, but I could have sworn that you can just use an e36 head/block/timing stuff (which is better anyhow) and swap over the e30 IM and stuff on top. To my knowledge the longblocks are the same other than the timing case. In any case, may want to google it and see if I'm right, since e36 M42 should* be easier to find. In the end, the M42 is just as reliable as the M20 and M50 = which is to say, they're all pretty strong but all have a weak point here or there (the M20, it's the rockers). Most e30s dont' DNF from engine failure (well, Downey has had issues with M54, but he's an exception.).....they break suspension stuff or have electrical issues, in my experience. But who knows. I wouldn't be scared of another M42. I've always found them to be pretty bulletproof if the timing stuff is in good condition.
As you've seen in my thread, M50 is not a hard swap per se, but does take a while to round up all the parts needed. M50 is direct bolt-up to your G240 transmission. What you want is an M50 in a 92-93 5-series, so you get the right oil pan. People want like $400 for those pans sold alone (e.g. if you start with an e36 M50). So you REALLY want the 5-series engine to get that. You'll also need to do some wiring (though IIRC it's not too different from the M42 C101), different arms/mounts. Also you'll need to change shift linkage, driveshaft since the transmission moves back wiht an M50.
M20 isn't hard either, but basically you'd want the full drivetrain from an M20 car, and it's drop in (obviously) aside from wiring.
M42 will still be substantially lower cost in the end. M50s with the 5-series pan are hard to find these days too (I've hoarded 3 of those pans for my own use....though Dan Downey has an unused one just sitting at Nonack's garage as of a few weeks ago ;)
All that is to say, you can do any of them, just a matter of how much work you want - drop-in/searching a bit, not drop-in but easier to find/more expensive, etc etc.
--
Side note, the problem with the firewall is interesting, but I guess it's because you have a fuel cell. My rear firewall is totally cut out, but I have a stock tank.
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Well, at least you got that DNF out of the way, so there's nowhere to go but up!
¯\_(ツ)_/¯ said:In reply to Berck :
You're in L2wd as long as the engine is 2500cc or less and came in "the same model range" which there's a pretty good history of "any 3 series" meeting the intent of. Swap away if the engine fits those parameters. The interchangeability would make the newer M42 less appealing then.
Not all 3-series engines are under 2500cc. There are M5x variants that were 2.8 and 3.0L (like Downey's).
All M50s are under 2.5L
The M52 B25 is under 2.5L but more trouble and less power than an M50TU (what I have), but there are larger M52 versions as well. Same goes for the M54. Also keep in mind those are OBD2 engines so more complex wiring to swap them in. If you want a six, look for M50. VANOS and non-VANOS are both fine. People are scared of VANOS so those are usually cheaper (and more powerful), and VANOS refresh isn't difficult.
M54
Man, just trying to find simple answers like, "What's needed to put an E36 M42 into an E30" is enough to drive me crazy. The answers seem to vary from, "nothing," to, "all the wiring and the ECU."
This answer sort of makes sense: "You will need the E36 ECU & wiring harness if you plan to keep the dual track intake manifold from the E36. To use the E30 Motronic & wiring harness, you will need to convert the intake system to the E30 manifold which is completely different, and swap all of the wiring. Your best bet is to find a good E30 M42 and put that in to your E30." I think this lines up with what you're saying as well.
I'm not entirely sure what "swap all of the wiring" means.... presumably use the E30 M42 engine wiring harness for everything? It looks like the E36 M42 came with a knock sensor which doesn't sound at all important to anyone on the internet, but sounds important to me for recent reasons:) I'd obviously need the E36 ECU for the knock sensor to be worth anything.
I'm liking the idea an M50 or M52. I'm not that afraid of just "ordering some parts", but scared of spending days trying to figure out which part and ordering 3 of the wrong one. So I don't have a G240, I have a ZF310 and who knows what dif with a 3.9ish ratio. The gear linkage I've got appears to be hand-made with some threaded rod.
eBay seems to be the only place that has several engines for sale, and none of them are cheap. The Z3 M52TU I linked to up there is the best deal I've seen yet, though much of the internet seems to day that "dual VANOS is evil", and I'm not keen at adding overly-complicated BMWness into my life. That engine would need the right oil pan, but they are readily available for the $400ish you mentioned on ebay. I assume this one has the right oil pan, but is also $400 more expensive. https://www.ebay.com/itm/265620660637?hash=item3dd839a19d:g:HXgAAOSwyd9iQ8zv
What else would I need? M50 exhaust headers for the E30 don't appear readily available. Also seems like custom headers are probably beyond the purview of your average exhaust shop? What about the drivetrain? Given my ZF310, who knows what driveshaft/flywheel/clutch I've got?
It's sad that I've already forgotten "all the things" needed, but I definitely documented ALL of it in my thread. I do that thread as much to remind myself of what I did as to show others lol.
For headers, buy the e36 cheapy ebay tubular headers for the M50. They fit fine and give enough clearance except one spot where you have to dent one of the tubes to clear the frame rail. They're what everyone uses.
ZF310 *should* bolt right up to the M50. M50 bolt pattern and everything are identical to the M42, so if it fits one, it should fit the other. Just swap over the starter, flywheel from the M42 to the M50 and it should fit directly. That said, I'm not 100% positive since I have a G250 at present and had a G240, but never a ZF. But it *should* work fine. Again, you may need a shorter driveshaft since it will move back though. Can't say for sure though.
Swapping the wiring shouldn't be hard if you get ane e36 M42. It's easy to do if you're removing the IM anyhow.
This is the most useful M5x swap site I've found. It's not 100% complete but has a lot of detail and a full parts list (some of which you may already have from the Z310 swap, and some you can work-around with other stuff): https://www.e30zone.net/e30wiki/index.php/Engine_Swap_-_M5x
I'm not going to lie, the M50 swap was definitely more work and parts than I had initially expected. I consider it to have been "worth it" for my purposes, but then again I sold my M42(s) for about what it cost to get most of the M50 stuff so it was not much of a financial thing for me, and I had plenty of time to do it and didn't have to rush. The best way is just to go to the JY and find a 5-series with the engine and pull everything. Or do what I did - go buy a beat-up but running '92-93 525i ('91 has an M20, so don't buy that). Then you'll have most of the parts already. It's amazing how many cheap 5-series pop up here and there, at least in this area where all the soccer moms have moved to more modern luxo-barges :) YOu may not have quite the selection out your way, but search metropolitan areas where people have some money.
That's about all I have for you at this point. Yeah, the internet has some wrong information on this stuff and it's not super-easy to find, especially if you're already running non-standard stuff (like your transmission) - much as I was with a M20 flywheel/clutch with M42 trans with M50. Most of this stuff goes together in one way or another though. It may just take time to figure it all out.
btw, if you have a 3.91 diff, that's actually probably from an early 318 (M10 car), which came with that ratio and many had LSD. That's what my car had originally. Not sure if that ratio was used on the 6-cyl cars or not. Your car would have come stock with a 4.10 to go with the M42, but the p/o probably needed a longer ratio to go with the shorter gearing on the ZF trans. 4.10 would be screaming on the highway with that 4.10. Same reason I swapped my 4.10 out for a 3.73 when I did the G250 swap.
Thanks, good info. I really wish GRM had a search-in-thread feature. Mostly for your thread:) Maybe I should just write a browser extension to do it.
Do you feel like the extra power from the M50 is significant for rally use? I know you said "worth it", but I get the impression you value time spent in the garage at $0, or even net-positive given that you enjoy it. I don't hate it and sometimes enjoy it, but I'd rather be driving.
If my M42 is rebuildable and a good deal nearby doesn't magically appear here soon, I'm thinking there's an advantage to having something fresh I can count on. If it's not, I'm starting to thinking that spending as much or more on an M42 of uncertain quality is crazy if the M50 swap isn't that bad. Still, $900 for quality pistons alone makes this sound like some very expensive insurance.
I've been reading the e30zone stuff. Great information and nice presentation.
Whole cars... https://www.facebook.com/marketplace/item/537688601329538/ Considering it comes with the ECU and wiring harness, not terrible. And I could do the world a favor by taking this thing off the road:) On the other hand, the drifter selling it has surely been kind to it. On another hand, the engine's held up to the kindness thus far? And I'd need to buy the right oil pan. And run a novice restrictor for ARA.
The M42 was a fun, revvy engine but seriously underpowered for some of the east coast rallies that have very large, long uphill climbs out of slow corners. Plus our rallycross venue has some seriously steep climbs as well. The M50's torque really helps for that kind of thing, but of course with the extra penalty of weight and not as good balance with a good chunk of iron sitting up in the nose. The car definitely isn't as light on its feet or well-balanced, and I had to do a good bit of suspension mitigation to get back to a neutral-to-oversteer balance that I prefer. The car with an M42 really has near-perfect handling balance....M50 definitely requires a change in driving style to some extent.
That said, with the ZF transmission with the M42 and a short diff, you probably have better gearing than I did with the G240, so your car is almost certainly quicker and better out of corners and up hills.
Yeah, I did the swap in the off-season when I didn't have any racing to do, and I was accruing the parts for months before I started since the car was still running find with the M42. So I basically got everything together and then did it all over a few weeks with no time constraint. Not necessarily your situation of probably wanting the car back on the road sooner than later.
Also keep in mind if you do rebuilt the M42 you have and it's in good running shape, then you can take your time getting all the M50 swap stuff together and once you do the swap, you'll be able to sell the M42 for a return on investment - so that's another option.
That link is to an M54 (?) 2.8L, so it will bump you to open class. Plus it's an OBD2 car with some other things and definitely more complex for wiring and stuff vs. an early M50. Even more powerful, but I personally like the early simplicity of the OBD1 M50 vs the later M52/M54s, which are more complex mechanically and electronically. But of course, it can be done as well.
It's a '94 so there's something you have to do about the ECU (I forget what) since it has some extra stuff vs. the 92-93 models, but the internet knows what needs to be done.
Thanks! You're way better at this Facebook marketplace thing than I am. Definitely more worried about the "new" head gasket than an untouched engine, but that's certainly promising. And I like the idea of having the whole car to get parts from. Agreed that simple is better when it comes to this swap, and if the OBDII cars are harder, I'll steer away from them. Oddly I'm less concerned about open class than the hassle of fabricating a restrictor to run for a few rallies. What kicked you into O2WD?
Mostly just the fact that I don't care. L2WD around here you're mostly running against Fiestas and other FWD quick cars (plus Nonack's BRZ, and others). O2WD is where most of the older RWD cars live, so it's just more fun to race against them.
The only things on my car that technically put me into O2WD are
- the tall trunk spoiler (easily removable)
- the removed spare tire well (I *think* by the letter of the rules, but debatable).
Either way, I'm not a fan of rules, so I just usually prefer to run top class so i don't have to care about rules. My bone-stock e30 ran in MR class in rallycross long before it was required to.
The '94 M50 swap has some oddball thing you have to do regarding the DME - making it a bit more work than the 92-93 cars, but I don't recall offhand what that thing is. Maybe an immobilizer unit or something? Probably something you can bypass if you have the entire car (or take the immobilizer module). But again, you'll be able to find what the deal is on the forums pretty easily. Other than that, the engines are the same, IIRC.
side note: I got $350 in scrap for the 5-series shell, and I think scrap prices are pretty good right now. There are some things on it you could sell to recoup as well. I sold the same mesh wheels for a couple hundred bucks off of the one I had.
Berck said:In reply to Crenshaw :
I'm in Divide (in the mountains west of Colorado Springs). I'm definitely planning on CHCA to start--waiting to see what the schedule is and which events will conflict with RMVR, as RMVR events will take priority. I don't really know anything about any of the CHCA events, but Monarch is pretty close...
Did you get to run your BMW this weekend? I did see a white E series BMW running. A person I spoke with about about the race mention a Blue Miata with a V8 running it but was not there. I thought he was talking about Keith.
In reply to MyMiatas :
Nope, haven't even pulled it off the trailer from Rally Colorado yet. I've got a lead on a cheap m42, though, so I'm leaning going that way for time and money savings. The blue V8 Miata that runs with CHCA is indeed a Flyin Miata car, but is not Keith's. https://www.roadandtrack.com/motorsports/a33806292/flyin-miatas-v-8-swapped-nb-hillclimb-car-driving-video/
Came across your forum and thought I would ask. Thank for the quick answer.
Well, I went ahead bought this. From another '91 318is, so it should be the same. Seller says it ran when he pulled it. No idea how many miles, the car he bought it in said 130,000 miles with a broken odometer.
Trying to decide how much to pull apart and refresh before installing it. Since refreshing things is a lot easier while the engine is out, I'm leaning toward "most of it". At a minimum: oil pump, relief valve (the oil pressure in my M42 was way too low, and apparently there's known problems with relief valves), water pump, timing chain and cams. Leaning toward pulling the head and having it gone through as well, but leaving the bottom end assuming the cylinder bores look okay. I'll swap over my fancy steel oil pan.
Note sure why the engine didn't come with the entire intake, but probably because he removed it when pulling the engine. I'm sure mine is fine, so it's no big deal, but in retrospect might have been nice to have a spare set of injectors so I could send them off to be cleaned.
I'm open to suggestions about how much to refresh...
With little BMW specific knowledge, I'd probably do everything that's difficult in the car which seems to be what you're already planning. I'd also take a good look while the oil pan is off but probably not do anything in the bottom end unless there's an obvious problem. Given the age I'd think really hard about front and rear main seals too.
I pulled the engine. The internet says this takes 3 hours. It took me an entire today. Not all of it was spent rounding off 12mm bolts with a 13mm socket, but some of it was. (Whoever last replaced the clutch slave cylinder thought it'd be funny if the exterior size of the top bolt was 12mm and the bottom was 13mm. BMW should hire the person, they'd fit right in!)
I didn't have my a camera nearby for the questionable dangling the entire engine/transmission from the single front engine lift point--but the technique worked. I'm also certain that removing the throttle cable from the throttle body before pulling the engine is probably a better option than removing the throttle cable from the throttle body with the engine hoist. Unlike much of the car, that throttle cable is impressively strong.
Probably hard to see what's going on here, but I'm holding the engine mount bolted to the part of the subframe that it bolts to. Only that part of the subframe is no longer part of the rest of the subframe.
I didn't notice it until I went to unbolt the engine mount. The engine was resting on the front subframe/steering rack on that side. I suspect it's been that way for a long time. Given that I still don't weld, finding someone to fix that is probably going to be fun.
Working on this car is not making me love BMW. I spent a stupid amount of money on timing parts. So much that I'm wondering if dropping the replacement engine in un-touched wouldn't have been the smart choice. BMW maintenance parts are so expensive! Unless you buy URO parts, then they're even more expensive because you have to buy them twice. Also, slanty engines don't balance.
It's extra fun for me since I have no idea what things are supposed to look like. The clutch/pressure plate/flywheel I pulled out look really worn. I'm not sure if this clutch disc had grooves in it, but it doesn't anymore. I didn't take any pictures, but now I need to go back and figure out what parts I have, because after looking at pictures online, they're not OEM. The flywheel feels pretty light and has a fancy friction ring bolted on. I'm hoping I can figure out what aftermarket flywheel it is and find a replacement ring because it looks rough and there's not enough material for it to be machined.
I wouldn't bother with replacing the timing chain, they don't really go bad on M42s, especially with that low of miles. Make sure the profile gasket looks good, make sure it has the updated chain guide and a fresh tensioner. M42s are pretty stout. I definitely wouldn't bother with the bottom end. Honestly, the M42 I just dropped into my project e30 I didn't do anything with the block or head, just updated the timing stuff, new water pump, new front/rear seals. I documented it in my thread. Same with the M42 the rally car had for 6-7 years with no issues at all. Why are you replacing the cams? I've never heard of them being an issue on these - especially with only 130k miles.
M42 stuff is a bit pricey only because it's not very high volume compared to other e30/e36 engines.
The subframe ear shoudln't be too hard to fix. Surprised he didn't have it reinforced already - but usually they break in the middle around the bolt.....I don't think I've ever seen one break completely off like that! Is the subframe rusty inside? If so, may just want to find a new one.
you need to figure out what flywheel/clutch you have if you haven't already. I use an M20 flywheel/clutch (stock Sachs clutch).
The subframe ear is also a little broken in the middle, but there was a big washer on it so it wasn't obvious until I unbolted it. The subframe doesn't look terrible. Good enough that it's not obvious that a replacement would be much better other than the broken bit.
I'm tempted buy a welder and try my luck...
Oops, I have no idea why I said I was going to replace the cams. I think I meant to say cam sprocket. But those aren't available, so I won't be replacing it. The timing chain was $60 and I already bought it, so that's not a big deal. (Some internet sources say the timing chains are only good for 100k miles? I'd think a chain should be good for 300k+, but what do I know?) I bought all of the various chain guide parts ($300ish total), except for the one that's no longer available. Not sure which of the ones is the updated one you're talking about? I also bought a new idler wheel/sprocket, because of the whole thread about how they go bad. ($150). I'm okay leaving the bottom end alone--whatever went wrong with my last one was top end. Single data points aren't all that valuable, I know, but that particular one stings.
The "sharp-edged cam sprocket is bad" is a fallacy. Having owned like 5 of these engines, and read stuff others have said, it appears BMW actually made two different types for unclear reasons - some had a sharper "tip" on the gears and others were flattened out. The sharp ones are NOT worn-down like some people say. I've seen 50k M42s with super-sharp ones and 200k M42s with perfect squared-off tops. So I'm 99% sure it's not a wear thing, but BMW just changed the design at some point for one reason or another.
The rally car's M42 had like 250k on it (or more, who knows) and had the original chain. I'm sure it happens, but generally there aren't chain issues unless the tensioner is bad. The weak point in these timing cases is the lower idler sprocket, so make sure that one has good/smooth movement. If it seizes, that's when chains get broken and stuff. That said, $60 isn't bad for peace of mind.
I'm talking about the "rail" (on the right when facing the front of the engine) that the chain runs through a "groove" on. The original ones were plastic AND metal and would delaminate. The updated piece is all plastic. Your old engine I would HOPE already had that part updated. Again, check out the build thread for my e30 (not the rally car, the more recent one) and I talk about it in there and you can see what I'm talking bout. I think you probably bought this as part of taht $300 purchase. They're not cheap. I got lucky and found a lightly-used one for my current build, but they're pretty hard to find on the used market these days. The tensioner guide on the passenger side usually aren't an issue. The updated tensioner piston is a good idea though.
In reply to Berck :
I'm enjoying your posts - please keep up the thread. I raced Hondas before moving to a BMW series, so a lot of your serviceability comments resonate. Lots of guys weld two nuts to the back of an arced metal plate to make installing and removing the starter easier. Others of us run with only one starter bolt (not going to recommend that for rally though)
I race an E30 but on smooth asphalt. I would replace that front subframe, not fix it. Replacing the front subframe is relatively trivial once the motor is out. They are relatively available in good shape, and it's worth noting that even in excellent shape, the area around the ball joint stud that mounts the control arm is a known failure point. I would recommend working on reinforcing an excellent one, not a rusty one. You can buy reinforced subframes ready to install from AAF Raching, Garagtastic, and likely many other sources. While we're on this topic, I'd also replace your front control arms on a schedule (not sure how tough rally is on control arms) - like once a season, and always use a torque wrench on those long ball joint studs - folks tend to over-torque them leading to failures. Any form of front control arm failure is exciting.
Lastly (for today), I'd put wheel bearings on your list of things to replace in the shop (proactively), not in a grass field. On the fronts, the inner race will get stuck on the spindle, but it can be split by cutting most of the way through it with a Dremel, then using a cold chisel very carefully. The rears are much, much, much, much, much easier with a hub-tamer
Looking forward to updates.
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