1985 BMW 318 Stage Rally Build - 1988 Porsche 924S Street Build - Sequoia Build

After being 14 seconds back after the first run I managed to get back within 6 seconds of Gorka after the other 8 runs (a second a run) so not so bad the rest of the day.

I was looking at my tires and I don't have much of a fresh edge left on the outside. I need to check the inside and see if I need to take them downstairs and flip them. But I think I put the better side out first.

It sucked having a decent first run and then getting told ok that run does not count and you will be first car after the water truck. Before water truck http://youtu.be/hq9DNCvHQOE After water truck http://youtu.be/7wKOW5Qy9N8

I was not driving as well as I should have today. Class winneritis setting in for the year I guess. I need some sort of new challenge for the last event.

moxnix wrote: After being 14 seconds back after the first run I managed to get back within 6 seconds of Gorka after the other 8 runs (a second a run) so not so bad the rest of the day. I was looking at my tires and I don't have much of a fresh edge left on the outside. I need to check the inside and see if I need to take them downstairs and flip them. But I think I put the better side out first. It sucked having a decent first run and then getting told ok that run does not count and you will be first car after the water truck. Before water truck http://youtu.be/hq9DNCvHQOE After water truck http://youtu.be/7wKOW5Qy9N8 I was not driving as well as I should have today. Class winneritis setting in for the year I guess. I need some sort of new challenge for the last event.

Yeah, trust me I know. Remember I ran that mud run directly after you, and my video of it looks eerily similar (even our offs and cone hits were in the same areas)......

I looked at your tires and they're worn about the same as mine on the outside (and I also put the best side out when I mounted them), and those things are so chewed I'm thinking even the snow tire guys have way more bite than use when it gets muddy.

Last event.....BMW guys drive the RX7s and RX7 guys drive the BMWs

Or we all drive at least one run in reverse. Class standings in top-3 are settled now so might as well, haha...

one other interesting little note from the last event.....

The 4-person ETA team had a bit of an issue when they put two large cracks in the right rear suspension tower just two runs into the day (keep in mind, the car has run three seasons with 4 drivers per event, so it's more like 12 seasons of rallycross!).

After much scrounging of random scrap parts from other people and random toolboxes, they put together a "repair" and proceeded to run the rest of the day (about 20 more total runs on a rough course). e30 = the toughness.

also, the rough course revealed a "repair" a previous owner had done on Nick's e28 in a rusty area of the wheel well. It was revealed when it fell out. Yay clump of fiberglass, painted to blend in with the metal...

So in the meantime, I've also been working on the M42 a bit. Basically have it most of the way back together, now that I got the final pieces of timing gear. Ended up buying a new (updated) chain guide and new chain. MIght as well just DO it while I'm in there, right?

Everything back together good, except I need to pick up a longer bolt for the odd top fitting of the chain guide. Once that's in I'll put the upper timing cover back on and button it all up...

Removed the "mess under the intake" and TB preheater too. Still need to get the right hose there going to the port on the head, but will find something that works...

Mustang injectors in there

In the "what the hell" category......I need new exhaust studs (they were missing when I got the engine), and it turns out the M42 uses an M7 stud, which is basically impossible to find other than ordering it special from BMW. Why they didn't use M8 like every other damn e30 engine is beyond me.....annoying though. Even Fastenal and McMaster don't have them.....

Some other stuff to put back on , and a coil pack that I got from Stuart.

In other things, most of the gauge cluster is now not working well, aside from the speedo and fuel gauge. The temp gauge bounces all around and the tach is dead. And this cluster has new board batteries, so I think all the banging around just knocked something loose inside it. This winter I'm going to ditch it entirely and build a panel there (and also in the center console) and just put some standalone gauges for everything in the car. One less BMW electronic piece to deal with....

and since I neglected to post any good pics from the last event, here are a handful that I and others took:

typical grid line shenanigans. Reminds me I need to put some through-bolts in my rear bumper pistons, since everytime someone bumps me the bumper gets cocked outward on one side and I have to kick it back in , lol

Spencer getting sideways

The ETA boys skipping the course entirely to find a very large, very deep mud puddle

Nick in the e28

with me

making a path for the water truck

Matt B in his MA H6-swapped impreza that dominates most events

subies

the competition - Roberto and Gorka

Doesn't get much closer than this. The cone wobbled but stayed put

and more here if you want to see them http://s78.photobucket.com/albums/j85/irish44j/BMW%20318i%20RallyCross%20Project/Summit%20Point%20Rally-X%2010-14-12/#!cpZZ1QQtppZZ24

some detail work tonight. Made it to fastenal and picked up a few random bolts I needed, since with the A/C delete and bracket gone, I can't use the very long (100+mm) bolts that used to go there, so had to find some shorter ones that fit.

Got the correct (45mm) upper allen bolt for the timing chain guide rail, and got that installed, then it was time to button up the case.

Got it on, got all the bolts on, and then realized I forgot the gasket for the center part (around the thermostat area). So back off....and back on again. One issue I had, with the new profile gasket there, was that the top of the timing case was sitting a mm or two above the top of the head. I couldn't get enough leverage to press it down (also tried some clamps, those didn't work well). Then came upon the trick of putting two large screwdrivers in the cams and using them to lever the case cover downward and level, compressing the profile gasket. Worked like a charm.

Also remembered to put some RTV at the corners of the profile gasket where it's notorious for leaking. We'll see if it works, not holding my breath.

On to finishing with the "mess under the intake." The last part was to either plug (as some do) or connect the outlet on the head to the outlet of the coolant pipe thingy. I went with the latter. Since they're two different diameters (as you can see in the first pic below), I used some thinner hose on one end that fit inside the larger hose for the other. Also kept the larger hose from kinking since it's an odd double-curve.

Finally with that done I was able to clean up the wiring box and put it back on, and get the main harness partly hooked up. Not sure why I'm doing this now, since it's sure to get in the way later, but I was bored so whatever....

starting to look like a real engine now. Well, as real as an M42 is :)

And that brings me to a new development....I just picked up another M42, complete with all accessories (including exhaust) today for $300. Well, I didn't actually pick it up yet, but I paid for it. Engine apparently has 120k original miles on it too, which is pretty amazing by itself.

The main reason I got it, in truth, is because it comes with a bunch of stuff that I otherwise would have to get seperately: - full stock exhaust (which I will modifiy a bit) - power steering pump/lines (which I don't have) - some other small bits that I needed - coolant hoses - a non-cracked oil pan - and other things I'm sure I'll pull off of it.

I may not actually keep the engine itself, as Spencer was also looking at getting it. So I might pull what I want off of it, and then sell the longblock and whatever else is left to him (or perhaps swap it to him for one of the corbeaus out of his rallycross car, which I almost bought earlier).

In any case, it will save me countless hours trolling the internet looking for a cheap used exhaust local, and an oil pan, and various other things. And in the end I may make some money off the entire deal, we'll see.....

Also, James Spoth (one of the drivers of the original ETA team here, and who I may run with in his LeMons e30 next year), posted up some nice pics of the e30 action at the last event, taken with a REAL camera, not my crappy point and shoot!

Well, work is on hold for this weekend as the storm of the millenium (aka "oh panic, rainshower Sandy is approaching") approches a direct hit on our area.

My cynicism aside (I've been listenening to the local weather forecasters for years and watching people go into extreme panic over 1" of snow here).....but that aside, took some preparations, considering my house is surrounded by very large trees.

So first spent some time clearing out the other bay of the garage to get another car inside. That gets the 4Runner, Triumph, and WRX under cover.

a tight fit on the WRX with all the other crap in there!

Unfortunately for the e30, since it's worth the least, it gets to ride the storm out outside. NOt that I'm terribly worried about it, but did do a bit of weatherproofing, mostly just to keep the expected 4-8" of rain out of the car. Doesn't matter too much since the whole interior is bedliner'd, but whatever.

Pulled the plugs, used some race magnets to cover the hood vents (including some GRM protection!), and some tyvek tape to seal up the HVAC intake vents (where I get most of my leaks) and the trunk (since that ALWAYS leaks, even with new seals...

so, hopefully all is good....and hopefully all is good for those of you who are also in the storm's path!

Damn... I should have done the tape thing to the trunk of my car... good idea.

Unfortuantely, my E30 lost it's garage space to the TDI and the GT6, so it gets to ride out the storm in my back yard. If I'd had more time, I would have cleaned it up and put the cover on it.

So.....the storm of the apocalypse put not a drop of water inside the car or in the trunk....and we got around 6" of rain and 70mph winds going sideways, so that's saying quite a bit for my weatherproofing methods :)

Helps that earlier this year I replaced and/or repaired all the weatherstripping/door seals (all with used stuff, but it was in better shape than what I had on the car when I got it).

Other than some leaves piled up, it rode out the storm nicely :)

early this morning.....still blowing 60mph or so. Hard to tell in a photo

for context.....these are the trees behind my house. They aren't small

later in the day, once it calmed down. We had no damage, no trees down, hell, hardly any branches down. I'm always happy our house is kind of on a hill (no flooding), but down in a small "valley" area overall with the whole cul-de-sac protected on all sides from wind by woods and other trees, so our trees/houses don't take the brunt of the wind force, usually.

also managed to crack my head open. Nothing to do with the hurricane though.....I was feeding the dog and when I stood up I turned and cracked it on the corner of a cabinet. Very bloody, did not feel nice. Don't think I needed stitches though so just dealt with it. If it scars, it scars, lol...

and the car.....none the worse for wear, except for some leaves piled up around it.

sadly, my cousin's house up in maryland didn't fare as well. He is deployed Army and luckily his wife and kids were sleeping in the basement, because a huge tree landed on the house and ruptured a gas line, and the whole place burned to the ground (they got out ok, but with nothing other than the pajamas they were wearing)....

Glad it missed you. I am never coming back to this thread, because now I want another E30

ok, so time for some more actual work.

Mail came today with a fuse box and round C101 connector from an early-ish M20 car courtesy of Dave (the admin over at M42club.com).

Why do I need this? Because my early '85 car has the square 19-pin C101 main bus connector for the engine, and square don't fit with the round 21-pin C101 on the M42.

Here's the M10 rectangular C101

Here's the M20/M42 circular C101

Instead of direct-splicing all that wiring, I decided to do a hybrid setup.

I have a spare M10 harness sitting around, so I took the female C101 plug off of that and spliced it to the M20 round C101 female connector. That way I can keep my old fusebox and not have to deal with all that wiring too, and I can plug the M42 engine harness into the M10 connector at the fusebox.

There are a few complications here, since my very early car has a few non-matching wires with the M20 car (a couple diagnostic plug wires, and one I haven't been able to identify yet). And then the M20 plug has a few differences with the M42 plug, so I'll have to move 1 pin (I think) and also add a couple other pins for wires that are seperate in the M10/M20 setups (like the DME control wire).

Anyhow, figured it's something to do while watching TV, and so I don't have to deal with it once I actually start the swap itself in a month or two.

Luckily, there are some good resources out there. I'm using in particular this page: http://www.bmw2002faq.com/component/option,com_forum/Itemid,0/page,viewtopic/t,356432/highlight,/sid,084321379222116dc0f89c3ff1bb7b0d/ which deals with M42 swap into a 2002.

Also this one, a nice diagram of the two different C101 plugs that someone posted on photobucket

here's my new wiring, and my box 'o wires

and these are my conversion notes for the three different connectors. Need to clean it up a bit, but getting there...

In other news, I happened upon my PS pump for this engine. I totally forgot it had one when I bought it.....had stuck it on the back of a shelf someplace and was actively looking to buy one on the forums. Happy I found it before I bought another one, lol

Next rallycross (the last of the WDCR season) is just over a week away now. I'm also starting to work on "recruiting" for next season, as I talked to Adam (the guy running rally-x program now) and said I would take the reigns for some "marketing" of sorts. So my first try was on Miata.net. This is a tough sell since to run the miata guys have to have a hard top, and most of their cars are set up for track or nice-weather cruising. But there were several Miatas at nationals this year, and running in other regions, so it's time to see if I can recruit some more locally.

I'm using Evan's turbo miata build in DirtyImpreza as inspiration for them :)

Jason and I went down with the trailer to pick up the other engine about 2 hours away in tappahannock. Loading it was interesting and the engine was in a wood shipping crate, and all the other stuff was in another crate. A lot of swearing, sweating, and improvising and we finally got it up on the trailer and back to my place.

Anyhow got this engine because it has several parts that I still needed: M42 radiator and hoses, uncracked lower oil pan, plug cover, shifter linkage, and some other parts. IT was supposedly maintained by a good shop and is low miles (120k, IIRC), so I'm hoping when I open the case I'll find updated timing components and oil pres. relief valve. We'll see.

Also came with the MAF assembly/elbow in good shap, another ECU (now I have 5 of them...), driveshaft, transmission, clutch/flywheel/etc, and all the hoses look to be pretty new and feel pretty firm. So hopefully for what I paid for it half of that is covered by stuff I had to get anyhow.

Also has all accessories, a couple AC compressors, two good rear shocks, some rear springs (not sure which), spring pads, and other parts that I won't need and can either clean up and sell to recoup some money, or take to the scrapper and get a few bucks for them (I have full AC system from two M10 engines here too, plus an m10 block and head, and other heavy metal stuff from old British cars that is rusting away)....need to do a scrap run.

Also like the sturdy shipping crates. I think I'll use them as a base for a new workbench :)

A bit of late-night parts-pulling from the new engine and I've found the following:

• it has the spark plug "BMW" cover. Not that I care much about the engine cosmetics, but in rallycross would rather have a cover on anything I can to keep it clean. That will get prettied up and put on the other engine.

• plug wires appear to be nearly new (will use them)

• there is oil in one plug cylinder - probably from the valve cover gasket leaking, i'd guess.

• pulled the oil pan. It's in great shape. No cracks, no scrapes. A rare unmolested pan, lol. Unfortunately, the oil left in it is pretty nasty. I can't tell, but there is a bit of look like it might have a bit of coolant in it. Not "chocolate milk" as I've seen before, but maybe......or it could just be old nasty oil that's a bit soupy. I guess when I pull the head on this at some point I'll see how the HG looks.....not really concerned about that right now.

dirty, and shocker there's a bolt from the upper oil pan sitting in there.......big surprise, not.

all cleaned up. I am a bit annoyed though. I ran out of Dawn, which I always use to clean up dirty engine parts. Went up to the kitchen to get some from under the sink......and it seems my wife is now buying some trendy dish soap of some sort. I tried it, but it doesn't attack grease nearly as well as Dawn does. Grr.

my old oil pan....JB weld repaired, scraped to hell. car it came out of was slammed, I know that for a fact

and one fail: realized that I forgot to put the oil pressure relief valve back in before installing the upper pan on the rebuilt engine. Need to figure out if that can be installed via oil reservoir/pump removal of if I need to pull the upper pan....again ;p

other things...the "new" engine has good adjuster ladders for the alternator and PS pump - mine on the other engine were all stripped, so those are good to have.

pulled the valve cover. Looking down in there it looks like it has the old-style chain guide (I have a new-style one on the other engine, brand new, but was hoping this one had the updated parts....)

hard to see here...

In better news, the timing sprockets in the "new" engine are in excellent shape - they must have been replaced at some time, or the timing tensioner was always kept good. EIther way, good-condition timing sprockets is an added bonus, since I wasn't expecting them.

ok, that's it for now....

irish44j wrote: I'm using Evan's turbo miata build in DirtyImpreza as inspiration for them :)

If that doesn't make them want to come out I don't know what will.

irish44j wrote: Next rallycross (the last of the WDCR season) is just over a week away now. I'm also starting to work on "recruiting" for next season, as I talked to Adam (the guy running rally-x program now) and said I would take the reigns for some "marketing" of sorts.

I'm local and have never rally-x'ed (rally-x'd?) but was hoping to pick up a new beater/city runabout in time to try an event this season. It's not looking likely before next weekend. When does the spring season usually start?

bluej wrote: I'm local and have never rally-x'ed (rally-x'd?) but was hoping to pick up a new beater/city runabout in time to try an event this season. It's not looking likely before next weekend. When does the spring season usually start?

March. But come out this weekend and ride along and talk with people.

Final Event (WDCR SCCA) and Season wrap (though I am running a Susquehanna Region event next weekend up in PA):

Big turnout today at Summit with 55 cars in attendance. Weather was perfect, and Adam Kimmett and his guys laid out the best courses of the year, including a double-loop section that I enjoyed quite a bit.

Coming into the event, I had a really, really outside chance of catching Gorka for 2nd for season points, but I would have to win the day and have him finish 5th or worse, I think. Shawn already locked up first for the season but knowing him he wanted to take 1st today after Gorka took it last time.

Morning runs were over 100 seconds for the MR cars. It was largely dry (with a few damp spots) and we also used the FULL "back straight" and I was able to use 3rd gear for the first time this season, extensively. We were getting up into the 60mph vicinity in that area, and some of the AWD cars were getting higher than that to boot.

Shawn started out the class run for the day with a dnf, forgetting to do the double-loop (since we don't usually have that feature, and he wasn't the only one who missed it), so that pretty much opened up first place to Gorka and I to fight out for the day, barring any big mistakes.

In the morning I ran right after Shawn and with four long runs in dry conditions I had a 4 second comp lead over Gorka at lunch break. Car was driving well and I pushed it harder in the speed sections than I had previously this season. Gorka was pushing it too, but I had him in raw times on all runs, I think. Unfortunately, I got 7 cone hits in those 4 runs and he only had 3, so my advantage was minimal.

We ran first in the afternoon, and with a trackday going on next door, the water truck did two full rounds of the course before we started. DAMMIT. That more or less erased my possibilities unless I drove perfect and Gorka screwed up.

First two runs were VERY wet and slippery, and Gorka's fresh rally tires had much more bite. I was all over the place and after 2 runs he had gotten 11 seconds back and taken a 7 second lead. As it dried a bit and I figured out some new ideas, I laid down an AWESOME third run - In my book, it was almost as perfect as it could be. AND......of course there was a timing issue (the timer said my time looked like it must have been one of the subarus, lol). So I had to re-run. The next try I was pretty good and still managed to beat Gorka by 1/2 a second. With 1 run left, pretty much had no chance barring a big mistake on his part. He didn't make that mistake, and ran it fast and clean. I ran the same time as him, but trying to eke out some time I clipped 3 cones (my vid shows they are all "just barely," but that counts of course...)

In the end, finished in 2nd, 12 seconds back with total times of almost 800 second for the day. WIthout the water truck I'm pretty confident that I could have taken the day, but water truck is part of rallycross, so that's the breaks!

Shawn pushed it hard and ended up adding a spin to his DNF, but otherwise his times were pretty similar to mine all day - so that's good since he was destroying me earlier int he season. I doubt he's regressing, so I guess I'm getting better. Time will tell.

Chris Nonack pulled off 4th behind shawn in his V6-swapped MR2, and Jason Reyonlds and Pat Henry took 6th and 5th respectively in their ETA-powered 325. Shawn's co-driver finished behind them. Nick and Bobby had issues with the e28 and called it a day at lunchbreak, leaking several different fluid types :P

Season: For the season, Shawn 1st: 56 points, 5 first place finishes Gorka 2nd: 48 points, 2 first place finishes and a second. Me 3rd: 41 points, 3 second place finishes.

Overall pretty pleased with this first season. I'm within striking distance and me and Gorka were tied until the last two events when he put the new tires on. So I'll come back next season with some fresh tires, 40% more power with the M42, and a few other tweaks and we'll see what happens.

WOrd is that Shawn is putting his interior back in and moving to PR, and Gorka will be running MA is the Audi rallycar he's building. Roberto (whose car Gorka drove this season) is reportedly moving up to MR after winning PR for 2 straight years. So he will be my main competition. We'll also likely have 4 or 5 BMWs in MR next year, plus the MR2s and we'll see what else.

results for the day: http://www.wdcr-scca.org/RallyCross/ResultsRX/WDCRRallyX72012111112/tabid/1753/Default.aspx

And a few pics real quick. More later :)

Gorka/Roberto's RX-7 (1st in PR, 2nd in MR for the season)

Spencer

The ETA boys

my "aero" mod. I actually was faster with this stuff up ther, lol

Gorka and Roberto

Scott Crowner, SR champ

Arun James in his PR Peugeot 505

The Euro crew:

M4 season champ Matt Berkebile in his H6-swapped impreza

SA champ Jim Golden

SA runner up....Mike Golden

Mike Newkirk in the Scirocco

Julian's last run, we left him a little present at our work station

grm style

actual stage rally car.....very fast

not as fast, at least not on this run

this freaking guy.....

dave shindle's nice lancia (not rallycrossing)

Nice write up and pics. Bringing a Lancia to a rally event and not running is almost a crime... granted, that car does look very nice.

You got the Golden boys mixed up.

Mike is #87.
Jim is #187.

Jim won first for the season. Mike was second.

moxnix wrote: You got the Golden boys mixed up. Mike is #87. Jim is #187. Jim won first for the season. Mike was second.

yeah, they informed me already, lol...

one of them needs to paint his car a different color!

Back to mechanicals. Tonight we look at the new flywheel/clutch stuff.

I got this for about 1/4 of the "new" price: - M20 single-mass flywheel (resurfaced nicely) - M20 sachs clutch (brand new) - 323i throw out bearing (new) - M20 starter (new) and a few other parts.

Anyhow, the M20 conversion is said to save about 4 or 5 lbs in overall rotating mass vs. the stock M42 stuff. Some people lighten it further, but I don't think I'll do that. Of note, there are about a dozen different methods that people say to do this conversion on the various e30 forums, so I've been trying to sift through the chaff and find out what the real deal is.

I think the method I'm going to use is the simplest: - Don't change the M20 flywheel at all, other than to use the spacer off the M42 flywheel to make the M20 wheel clear the oil pan bolts. - Use the M20 clutch as-is, of course - Use the 323i TOB (though some people say the 325/318 one is fine) - Use the M20 starter as-is (though some people change the gear onto an M42 starter for some reason).

Some pics of the parts below and more thoughts on the above. But first, let's take a looks at weights. I checked this scale using some workout weights, and it's good within about 1/2 lb give or take. Close enough for me.

so here's the M20 flywheel alone. About 16lbs.

Now the M42 flywheel alone. Remember, it's dual-mass. About 26lbs.

Now the full M20 clutch/flywheel assembly together. About 30lbs.

And the full M42 clutch/flywheel assembly together. About 35 lbs.

So, as expected that's about 5lbs saved weight from this swap.

Now, on to some other details: Here's what they look like side-by-side. The M42 left and M20 right. The M20 mounting face on the engine side is recessed about 3/16" or so from the lip it's sitting on, while the M42 FW face is flush with the mounting circle. So they're not "even" in this pic.

Also note on that how the M42 overall height is much taller. The M20 pressure plate splines do stick "out" more, but its overall height is still maybe 1/2" shorter (e.g. farther away from the throwout bearing once installed).

Here's a comparison of the TOBs. The 323i on the left and 318 stocker on the right. Though people say you can use the stock one, others use the 323i one. I assume this is to compensate for the difference in "height" of the clutch/fW assembly. Will measure more in the future.

And the starters. They are identical in size and both fit the bellhousing mount points. The length of the gear and its assembly is the same on both from what I can tell. Only real difference is that the M20 gear is smaller in overall diameter (I measured them, but forgot the numbers). Long and the short is that the M42 gear won't fit the M20 flywheel. Some people just swap the gears, but it seems to me that the M20 starter should work as drop-in, from what I can tell (and from what some other poeple have said).

So....will tackle assembly of this stuff once the engine is off the stand. Also not shown is the spacer that I removed from the M42 flywheel for use on the M20. It's a thin spacer but enough to make the flywheel clear the back of the engine/oil pan without milling or grinding of anything.

Also, my two Getrag 240s. This one came with the first engine, and the owner said there were no issues with it. I don't see any issues.....but that means nothing :)

Here's the one that came with the "new" engine. The inside of it is nasty with oil. So I'm guessing the rear main seal on the second engine is shot (though I don't see any oil on the back of the block or anything, so who knows...)

The engine is coming along, with all accessories installed with new adjuster "ladders" off the second engine that are in great shape.

getting a bit crowded in here...

One side project, Pat gave me his diff cover to press in a urethane bushing. So I have to do that sometime this winter as well.

He traded me a GRM t-shirt, brand-new, for my effort. BUt more because it's a large and he likes a medium to make him look more buff, lol.

Oh....one last thing. Also got an M42 ECU with the Jim Conforti chip - which is supposedly good for an extra 15 hp or so. As you can see, also have a bunch of regular M42 ECUs (every parts deal I've gotten seems to include one or two, lol).

Ian F wrote: Nice write up and pics. Bringing a Lancia to a rally event and not running is almost a crime... granted, that car does look very nice.

The fella that owns the Lancia has been in a number of championship rally cars. I think all the time in the Silly Seat.

more on the clutch stuff. Did some mocking up to see what method is actually best. Here's my take:

My workbench is PERFECTLY level, first of all. I used some blocks of EXACTLY the same thickness underneath the assemblies, simulating the mouting face of the block. So this display shows the relative heights of the entire assemblies AS MOUNTED on the engine.

All bolts are tight, and the pressure plates are cinched down to spec, with clutch plates inside.

FIRST TEST: This is the M42 stock assembly on the left. On the right is the M20 assembly WITH the little spacer underneath. As you can see, the ring gears on each are perfectly even. Both have a standard E30 TOB on top. As you can see, they are PERFECTLY level with each other.

So, the bottom line on this setup is that the full M20 assembly here, with the spacer and stock TOB, is exactly the same overall thickness as the stock M42 stuff.

M42 vs M20 w/spacer and stock TOB:

TEST 2: In this test, I took out the spacer ring from below the flywheel, and put the slightly longer 323i TOB on top instead of the stock one.

Results: The ring gear is a bit off. The overall height is exactly the same. So basically, this setup should work fine as well. I'm thinking that the 323 TOB method was developed before someone thought of using the little spacer to allow use of the M42 TOB. The only thing here is that the backside of the FW would have to be milled a bit to clear the engine/sump bolts. So this method involves a BIT more work.

Looking at the starter pinion gear travel, it appears that the M20 starter OR the M42 starter with the M20 cone should both work perfectly.

Thoughts?

M42 vs M20 without spacer, with 323i TOB.