E30 Rally Car

Hey, thanks for the ideas.  Sometimes I feel bad ragging on BMW about serviceability when sometimes it feels like irish44j is the only one reading and he's clearly a BMW/German fan:)  After years of owning/working on basically nothing but Japanese cars (mostly Miatas), it's hard to contain myself.  I forgot to mention that while pulling the engine there was a 16mm nut!  16mm!  I think it's the first time I've ever taken my 16mm wrench out of the toolbox.  Sizes found on my e30 so far: 8,10,11,12,13,14,15,16,17,19,30,32.  The only sizes anywhere on a Miata: 10,12,14,17,19.  Oh, and 23,24mm for the diff drain plugs.  I can replace a Miata timing belt, idler/tension pulleys and water pump with all the seals/gaskets for $200.  The single problematic idler sprocket on the M42 is $150+.

That Garagtastic reinforced subframe looks like a simple solution.  Trading some money for time, but that might be a reasonable thing to do at this point.  Of course, when I start replacing parts with fancy parts, I'm going to feel awful when I drive it into a tree.

Wheel bearings.  I have done nothing with wheel bearings yet.  That sounds like a terrible job that I should probably do.  I really don't want to, especially if it involves cutting out the inner race.  Sigh.

Did not know the control arms were that fragile?  New ones and carrying my old ones as spares is probably reasonable though if I'm replacing the subframe.

I'm here to support you in saying BMWs are dumb- I never managed to kill an M42 though so you get to say it louder than I do.

¯\_(ツ)_/¯ said:

I'm here to support you in saying BMWs are dumb- I never managed to kill an M42 though so you get to say it louder than I do.

Hah!  Thanks for the support.  Your thread makes me jealous, mostly of your fabrication skills, but also that those skills enable you to drive a RWD rally car that isn't a BMW:)  It's possible that the car is going to eventually endear itself to me, but it's got a pretty steep hill to climb after blowing up on my third stage ever.

In reply to Berck :

Get a welder and start zapping stuff together!  I'm not great with it but it's one of those tools that, once you have it at your disposal, opens up your options tremendously.  And if you ever want to put together a rally BRZ I have all the files ready to go to your laser cutter of choice- Subaru engines are sort of all grenades with the pin pre-pulled, but at least the bolt heads are normal sizes.  

So, the biggest thing stopping me from buying a welder is that I'd convinced myself that I need to have a subpanel wired to my garage first.  My entire detached garage is powered from a single 20amp 120V circuit.  The biggest limitation is that I'd need to spend some real money to have even a single 220V outlet.  Which I really do want to do.  Ideally it'd be great if I had 220V available for an air compressor big enough to spin a die grinder for more than 30 seconds, or run a pneumatic sander.  And be able to upgrade my table saw to something more than the 1hp motor which, with a nice blade, will rip 8/4 maple but is always just a slight nudge away from tripping the breaker.

A friend tried to use his cheap stick welder in my garage and it was basically unusable, tripping the breaker every 30 seconds or so.  Even with everything else in the garage off.  My takeaway from this was basically "110V welding doesn't work," but more reading makes me wonder if it's just the particular welder he was using.  Seems like with most of a 20amp circuit available, a nice 110V welder should be usable for much of the things I'd want to do with it?

I got away with 110v for a long time- on a 20a circuit you might pop the breaker occasionally if you're welding thick stuff, but I bet it'd be fine for exhaust work and little projects.

I use a 110 and have never had any issues even with thick stuff. Hobart 140, used to build my cage.....attached the huge D-rings to my trailer, and some heavy work. I have 220 in my garage but have never felt the need to upgrade the welder.  Only thing I use 220 for is my plasma cutter.

You could also run a thick-ass extension cord from a higher-amp outlet at the house as well. You may get a bit off voltage loss, but I've run my welder on a 50' cord plenty of times with no problem (out arond my house to where my trailer is). 

Berck said:

Hey, thanks for the ideas.  Sometimes I feel bad ragging on BMW about serviceability when sometimes it feels like irish44j is the only one reading and he's clearly a BMW/German fan:)  After years of owning/working on basically nothing but Japanese cars (mostly Miatas), it's hard to contain myself.  I forgot to mention that while pulling the engine there was a 16mm nut!  16mm!  I think it's the first time I've ever taken my 16mm wrench out of the toolbox.  Sizes found on my e30 so far: 8,10,11,12,13,14,15,16,17,19,30,32.  The only sizes anywhere on a Miata: 10,12,14,17,19.  Oh, and 23,24mm for the diff drain plugs.  I can replace a Miata timing belt, idler/tension pulleys and water pump with all the seals/gaskets for $200.  The single problematic idler sprocket on the M42 is $150+.

That Garagtastic reinforced subframe looks like a simple solution.  Trading some money for time, but that might be a reasonable thing to do at this point.  Of course, when I start replacing parts with fancy parts, I'm going to feel awful when I drive it into a tree.

Wheel bearings.  I have done nothing with wheel bearings yet.  That sounds like a terrible job that I should probably do.  I really don't want to, especially if it involves cutting out the inner race.  Sigh.

Did not know the control arms were that fragile?  New ones and carrying my old ones as spares is probably reasonable though if I'm replacing the subframe.

1. I mean, there are plenty of BMW things that frustrate me. But 100x less than all the annoying things my WRX had...I appreciate how 40-year-old BMW bolts don't shear off.....when 5-year old Japanese-car bolts do all the time :)

2. The downside to buying someone else's rally car project....you get to deal with all their hack jobs, wrong-size nuts, etc. One thing that never gets mentioned when people say "buy your first rally car, don't build it!"

3. Wheel bearings are pretty easy. For fronts I just buy the whole hub (Centric) from Rockauto. They're cheap. I've never had to cut out a race, to my recollection, and I've changed my front bearings a half-dozen times or more. Rears are pretty easy too if you have a bearing press tool (HF sells one). I've only replaced my rears one time in ten years though....they're beefy and don't go bad as easily.

4. Never had any control arm issues, personally. The e36 ones are more fragile since they're aluminum. The e30 ones are steel and though I've seen a couple broken ones that's usually from hitting something really hard the wrong way (like a curb). Don't recall any rally guys breaking e30 ones, offhand (could be wrong though). I do carry spares, but have never had to get them out. 

So, clutch/flywheel...  Presumably because my M42 was mated to a ZF310, the clutch pressure plate and disc is for an E36 M3.

So, that's a Sach's 1864098033 clutch disc, with a Sachs MF240 clutch cover bolted to a....  TMS (??) flywheel.  That's all the flywheel says anywhere on it.  "TMS". 

Does anyone think it's a good idea to reuse any of those things?  The clutch disc doesn't look terrible, but I measure .025" from the surface to the rivets.  That's less than 1mm of usable friction material remaining.  The pressure plate looks okay, but I didn't measure anything.  But that flywheel friction surface looks terrible.  No way the remaining friction material could be machined, as there are only .004" of material before the screw heads are flush with the friction surface.  Ideally, I'd find a replacement friction ring...

It's got to be an american made thing as the allen heads are 1/8" and the nuts are 3/8".  I've found JB Racing lightweight flywheels that have the same design, but it's not clear if the JB Racing friction rings will fit on it.  Or maybe this one?  https://www.drifthq.com/products/spec-clutches-aluminum-flywheel-friction-plate-bmw-m3-3-2l-e36-for-sb23a-1996-1999-sb23a-fpk?variant=31576740790319

Even assuming I find one that will fit, I have the additional problem that I'm not sure I can even remove the old one.  The outer bolts have a nut on the backside and removing them was easy.  The inner screws thread directly into the flywheel and won't budge.  I bent an allen key and broke the tip of a bit in one with a 1/4" impact, but they were cheap bits.  They're soaking in penetrant oil and I ordered some nicer impact bits to see if that will budge them.

E36 M3 flywheels seem to be like $500 for the lightweight aluminum ones like the one I have.  Other options seem *more* expensive.  Because BMW and E36 M3, presumably.

Oh, hey, this eBay clutch kit is completely reasonably priced.  Maybe way too reasonably priced?  I mean, I like the lightweight flywheel, but not enough to spend an extra $400 on one...

irish44j (Forum Supporter) said:

1. I mean, there are plenty of BMW things that frustrate me. But 100x less than all the annoying things my WRX had...I appreciate how 40-year-old BMW bolts don't shear off.....when 5-year old Japanese-car bolts do all the time :)

2. The downside to buying someone else's rally car project....you get to deal with all their hack jobs, wrong-size nuts, etc. One thing that never gets mentioned when people say "buy your first rally car, don't build it!"

3. Wheel bearings are pretty easy. For fronts I just buy the whole hub (Centric) from Rockauto. They're cheap. I've never had to cut out a race, to my recollection, and I've changed my front bearings a half-dozen times or more. Rears are pretty easy too if you have a bearing press tool (HF sells one). I've only replaced my rears one time in ten years though....they're beefy and don't go bad as easily.

4. Never had any control arm issues, personally. The e36 ones are more fragile since they're aluminum. The e30 ones are steel and though I've seen a couple broken ones that's usually from hitting something really hard the wrong way (like a curb). Don't recall any rally guys breaking e30 ones, offhand (could be wrong though). I do carry spares, but have never had to get them out. 

1) This is a fair point.  I've broken old Miata bolts, and thus far I haven't broken any BMW ones, including some really rusty looking stuff that I was sure *would* break.

2) Really good point.  It's a weird intro to BMW--buy a 30 year old car that's been a rally car for the last 15.  That 16mm bolt head was totally factory-looking though.  I've already forgotten where it was, though.  I'll make a note when I find it on reinstallation:)

3) Okay, replacing the front hubs definitely sounds like the easy way out and I'll just do that.  I have this and a hydraulic press... is that sufficient for the rears?

4) Good news.  New ones are $100/each, so it seems reasonable to do just so I can have the current ones as spares.

That isn't the harbor freight kit I have. It looks like it has some of the same things but mine has more pieces and a long threaded piece so you can crank with an impact  or a breaker barand pull the bearing right out, and also press it in. I will see if I can find the link to it when I get home. 

The one you posted may work as well I'm not positive.

In reply to Berck :

that looks like a centerforce pressure plate (yes I know its a SACHS), I had to cut that ring of weights off because it was throwing the balance of my engine off and shaking the whole car.  Those things were notorious for walking around and actually destroyed a throw out bearing. 

In reply to fidelity101 :

Good to know; I'll avoid similar designs for the replacement.  I thought those things looked awfully fiddly.  What is the purpose of those weights anyway?

In reply to Berck :

Diaphragm clutches had a habit of sticking disengaged at high RPM.  The weights pulled the diaphragm past its over-center so this does not happen.

It is no longer the 1970s and it is mainly a gimmick today.

Okay, replacing the front hubs definitely sounds like the easy way out and I'll just do that.  I have this and a hydraulic press... is that sufficient for the rears?

 

Type Hub Tamer into Google or Amazon, and you'll see the sort of kit you're looking for. You need appropriate sized tubes to draw the bearing out into, then the appropriate caps, and a serious high-grade pulling bolt to apply the pulling force. Whatever you do, keep the bolt that's applying the force well greased - especially if it's Harbor Freight or similar, as the bolts are made of high-grade bubble gum. For my trackside stuff, I carry an import set rather than the massive Hub Tamer Elite kit, but I replaced the big nut and bolt with Grade 8 hardware (3/4" diameter by memory) domestically sourced and almost the same cost as the imported kit. Harbor Freight has a FWD Bearing Install and Remover kit - that's the sort of gear you are looking for, but Amazon has cheaper sets.

On the E30 rears, you will need to press out the hub before you can remove the snap ring that retains the bearing. The first time, if the hub as been in there for 35 years, it's tough to get them out. After that, a slide hammer and a hub adapter makes it easy - then you can do the bearing right on the car with a Hub Tamer type tool.  

I probably made the fronts sound worse than they are, but I've NEVER had an inner race not get stuck on an E30 spindle. I've done front hub replacement in the shop, in the pits, and during an endurance race. Beyond a shadow of a doubt, the ones done in the shop always last longer. Trying to get a cold bearing onto a hot spindle is no fun.

Also, IDK why you're looking around for fancy clutches. I've been running stock Sachs clutches for a decade - with an M50 for half that time. The one I just swapped out after 7 years of rallycross/rally was still well over 50% wear remaining, without tearing up the flywheel, and I've never, ever, ever had any issues with clutch slippage that I can recall. And the M42 isn't going to have the amount of power/torque to tear up a clutch. 

In addition, we're driving on loose surfaces which are way less load on clutches, I would think.

Anyhow just a thought. I much prefer OEM-type clutch stuff than an iffy aftermarket brand or a $$$ "race setup." But maybe that's just me. 

In reply to irish44j (Forum Supporter) :

Fancy clutches mostly are a negative.  If they have no sprung center then they wreck transmissions, if they have stiffer pressure plates then they may stress the clutch fork/pivot and firewall, and usually have a really long throw too.

Puck clutch disks are OK because they cannot explode the lining the way fiber clutches can when they get hot, which is important if, say, you find yourself unable to use the lower gears and need to slip a lot to get moving (have driven home with nothing but 4th before...) but they work just fine with stock pressure plates.

Teh black RX-7 makes close to 2x stock torque and 3x stock power and it uses a stock clutch 

I'm not looking for fancy clutches!  Why do you think I'm looking for fancy?  I'm looking for the absolute cheapest thing I think I can get away with.  I'm assuming that since my car has an E36 M3 flywheel/clutch that I need to stick with that.  I'm pretty sure I can't run the stock M42 stuff with the ZF310.   Given that the ZF310 was the transmission on the E36 M3, I assume that's why I have an E36 M3 clutch, and I assume I probably need to stick with it.  If you know for sure that I can use something else with the ZF transmission, that'd be great.  I'm not seeing solid information either way, and I know the E36 crap works because it's what I took off.  Right now, I'm leaning toward that ebay kit I linked to which is a sachs clutch and a no-name single-piece flywheel for $329.  It's literally the cheapest least fancy thing I can buy.  I like the idea of a sachs clutch, but unsure about the no-name flywheel.  I can buy a sachs clutch without flywheel for $249 on Rock Auto, which could work if I could find a replacement friction ring for my current flywheel.  Which is the only other thing I was looking at.  Friction rings are about $100, so we're in the same ballpark, and I could keep my 10lb flywheel.  A stock E36 M3 flywheel is, in fact, fancy dual mass garbage at $1,000.  I'm not paying $1,000 for a flywheel that's also way too heavy for my M42.

While it's nice that the forum filters give me a nice shortcut for saying E36 M3, I wonder if that's what's confusing you? I literally mean the E36-M3 which may be E36 M3, and may be fancy E36 M3, but appears to be E36 M3 I'm stuck with.  Sigh.

Berck said:

While it's nice that the forum filters give me a nice shortcut for saying E36 M3, I wonder if that's what's confusing you? I literally mean the E36-M3 which may be E36 M3, and may be fancy E36 M3, but appears to be E36 M3 I'm stuck with.  Sigh.

Lol. Maybe I got lost in the discussion of stuff. I don't know offhand if the M3 clutch is the same size as the regular E36 clutch.  Definitely not suggesting you get M42 stuff. I just meant to buy sachs (also when I say that to my phone it thinks I am trying to tell you to "buy sex" lol...)

Cool.  Will 100% buy a "sex" clutch disc and pressure plate, and not one with the stupid weights.  I will probably not buy the stock E36 M3 clutch disc because it doesn't have springs, likely relying instead on the dual-mass flywheel to protect the transmission.  But that ebay kit has a sachs disc with springs.  Great.  The question is what to do about the flywheel.  OEM stuff is too fancy/expensive/heavy.  If I knew for sure that I could find a compatible friction ring to replace the one on my flywheel, I'd do that.  If anyone has leads on what a "TMS" flywheel is and who to contact, I'd make an effort.  Otherwise, I'm thinking the no-name one in that ebay kit is probably fine?  

Started pulling apart the old engine today.  Found this in the intake manifold behind the throttle body: 

One of these is not like the other:

Doesn't look like detonation to me.  I think it just swallowed the intake valve and then the shrapnel managed to bounce back into the intake and into two other cylinders.

The timing stuff looks like it's all in great condition and would actually be reusable.  I'm guessing that valve just got a little sticky and floated enough to get whacked?  Hard to know.

So, the head is completely unusable.  The block could be used with a 1mm overbore, I think, but my decision to just pick up another M42 seems reasonable.  Now to take *it* apart.

Oh, weird discovery.  My engine has knock senors, and one of them appears to be correctly wired in:

That would imply that I have an E36 engine and an ECU as well, I think?  The other one is a lot more confused.  It was connected to the harness with a single wire that looks like it was shoved across both pins.  Not sure how that could possibly work.  And I'm not sure where the heck the other wire is.

Okay, so I apparently have a much newer M42 than the one that would have come with my car.  My replacement engine is the one that would have come with my car.  Apparently the newer timing case doesn't need the expensive idler sprocket at all.  Thinking I should swap the newer timing case onto the older engine and return the timing parts I don't need, like that $150 idler wheel.  The engine in the car, despite being newer, does still have the old metal/plastic timing guide.

While disassembling the old M42, I noticed that the crankshaft end play is a good 1/8".  I'm guessing that engine wasn't long for this world even without the valve failure.  So, I thought I might have had a good crank spare, but I'm guessing I don't.  The one on the replacement engine moves enough that I can feel it, but I can't see much in the way of play so I hope it's okay.  I'll measure it, but a quick Google didn't find a spec, just people complaining about this being a common M42 failure.

So much for no broken bolts: 

Also, looks like someone went all Subaru with the RTV: 

Given that it's red, I'm guessing that's whoever pulled it apart last, not BMW.

Another 16mm bolt holding the timing case on.  Mixed in with 10mm bolts and some 6mm allen heads.  Just to keep it lively.

I still haven't started pulling the replacement engine apart yet.  I went ahead and checked the oil pump rotors in this timing case, since I'm going to use this one instead of the older style.  They looked perfect as far as I could tell, so I put them back with some assembly lube and decided to save the $75 on the replacements.  I did go ahead and replace the oil pressure valve with the new style plastic bits.

Next up, I'll pull the head in the new engine and find a machine shop to go through it.  I need to order the tensioning guide and one of the lower guides, since they're a newer style and mine have visible wear.  The lowest guide looks perfect, so I'll skip that one.  And send back the old style stuff...