'94 S52 6-Speed Track/Race Car

[circuit.heart]

Hey everyone! I'm actually coming in from the FB group after seeing that the forums are very much still alive. To introduce myself, I'm just a head-ass engineer modernizing an E34 to perform at E9X/F8X level, on a budget. Several years ago I designed some small adapters to put F8X brakes on the E34 platform, and proceeded to beat them up at the track to see if they were any good (spoilers: no).

001 by Brian Ma, on Flickr

002 by Brian Ma, on Flickr

003 by Brian Ma, on Flickr


Braking from 100mph down to 40 was absolutely terrifying, between pad knockback and extreme rear bias - but I did make my point at Bimmerfest 2018, E34 is not a slow chassis.

004 by Brian Ma, on Flickr


005 by Brian Ma, on Flickr


More pics in a bit since I can only upload 5 per post. Thanks for having me!

[m60power]

Welcome to the forums! Glad you're taking the time to post here instead of Facebook. Sounds like a fun project!

[dannyzabolotny]

Hey there, glad to see you posting on here! Your knowledge would be much appreciated here on the forum— I know I've learned a ton from reading about your experiences on the Facebook group.

Not to be that guy, but your images aren't working, you may want to look into that.

[circuit.heart]

I blew the engine AND trans driving home from that first Bimmerfest, which led to a hastily-built M52B28 and GS6-53BZ (the 335i 6MT) mated together, then bolted into the car shifted 1" back. Pairing the 6-speed to a 4.10 LSD is the best idea ever though.

006 by Brian Ma, on Flickr


007 by Brian Ma, on Flickr


Sometime after this, the car got wrecked by a red light runner and was re-shelled into a fresher '94 chassis with 168k on it. And that's where things start getting silly.

Stock-ish E9X M3 and F8X M3 are usually in the 1:58-2:00 range at Buttonwillow Raceway, depending on tire. The "new" E34 (we call her Sonata now, long story) went ahead and did 2:02's with a passenger, on a hot day, with a cracked radiator and a massive understeer problem from missing half the front bumper:

008 by Brian Ma, on Flickr




Aka, without the passenger it would be easily in the 2:00's. As you'd expect, running a track day with no pressure in the cooling system comes with consequences, and I blew the headgasket on the way home. This time, I thought we'd build an M50B30 and make a naturally-aspirated, M50-powered E34 do Sub-2's for the ultimate flex.


009 by Brian Ma, on Flickr

010 by Brian Ma, on Flickr

[circuit.heart]

Hindsight 20/20, this was not a good idea. The long crank + my close-ratio gears kept the rpm's constantly between 6-7000rpm, which eventually destroyed the woodruff key and caused a host of timing issues. As sweet as the engine performed when it was happy, it was the least reliable one I'd ever had in the car and I was constantly on the side of the road doing *something*.

011 by Brian Ma, on Flickr


After reading everything I could find about the M5X crank harmonic problem, it was decided that the next powerplant would have to avoid the harmonic resonance peak, even if it ended up being heavier or less efficient. Slow track time is better than no track time at all!

Brought home an M62B44 (non-Vanos) with 209k miles on it. Flawless bores, perfect compression test, and clean bearings, but cracked timing guides as expected. My wife chipped in to help me replace the crappy M62 parts with some M60 and S62 good stuff: the timing chain, guides, cams, and valve springs. Surprisingly clean engine inside, I count my blessings. Even the lifters that I took out were all squishy still.

012 by Brian Ma, on Flickr


Valve spring comparison, M62 to S62. Surprisingly not that big a difference, but as long as the S62 springs let me rev freely to 7000, I'm a happy camper.


013 by Brian Ma, on Flickr

M60 cams installed into the M62 head - note the gap near the 1st cam journal. I've got some shaft collars designed that will act as a "backup thrust surface" in case the cams do walk, but in general chain tension should be keeping the cams in their correct orientation.

014 by Brian Ma, on Flickr


And that's where we are at the moment. I just started a new job, time and funding are both tight. I just have Sonata sitting on her race wheels, dirty and uncared for, until the engine is ready to shove in.

015 by Brian Ma, on Flickr


Thanks Danny for letting me know about the images lol. It's been a hot minute since I've used forums...

[Smoky540i]

This is so cool! I thought most guys did the M60B44 build with the M62 block and M60 heads?

[5mall5nail5]

Nice going!

It's interesting you said the F8x calipers didn't work well for you - there are a bunch of people running them here lately. I had built a custom 6-piston Wilwood SL6R setup for my E34 that is working very well. Do you have any pics of the adapters you made for the front calipers?

[BleedsBlue]

I kept wondering if you were coming over to the forum side. Long live the forums. Love keeping up with a track-focused E34 build (and have been on IG) - please keep the updates coming

Nice going!

It's interesting you said the F8x calipers didn't work well for you - there are a bunch of people running them here lately. I had built a custom 6-piston Wilwood SL6R setup for my E34 that is working very well. Do you have any pics of the adapters you made for the front calipers?

Not to get into a tangent on this thread - we do have a standalone F3x brake thread if a discussion is warranted - but the OP was a pioneer with adapting those brakes, and confirmed some dimensions for us (when he still liked the brakes I guess, haha). One difference is that we never adapted the rear two piston brake calipers, as he did - and I believe he ran the 370mm rotors and calipers, which we don't recommend due to needless added weight.

Between Angry Ass and Denver Beer and Oil, we've had a few cars go hard on the 340mm/4 piston front and M5/540i 300mm/sliding caliper rear on multiple tracks, with higher speeds than 100mph, including in 25min sessions. Not one issue with knock back, rear bias (different rear setup, tho) etc - we love the brakes. But to each their own as they say - we do market our F3x-based kit as street-focused, because our true track setup is in production - AP Racing 6 piston calipers, 355mm J hook rotors, etc.

[circuit.heart]

This is so cool! I thought most guys did the M60B44 build with the M62 block and M60 heads?

Most do for the higher compression yeah. For me, since I've had 3 engine-out events in 3 years, my priorities are a little skewed:

- M62 lower compression will tolerate bad gas/excess cylinder heat just a little bit more if I screw up
- M62/S62 valvetrain is way lighter, so spring forces are lower and there will be a little less friction (heat) at sustained 6-7000rpm.

I expect this one to eventually die like any other engine I've raced, but I'd really like to get more than 2 events per build lol...

Nice going!

It's interesting you said the F8x calipers didn't work well for you - there are a bunch of people running them here lately. I had built a custom 6-piston Wilwood SL6R setup for my E34 that is working very well. Do you have any pics of the adapters you made for the front calipers?

I might not actually have taken pics of the front caliper adapters - it was literally an extended Class 12.9 bolt and a machined steel spacer, the same design as Angry Ass sells now.

Brake bias of course depends on tires, but I don't have much weight in the trunk and generally make over 1G deceleration under braking. The F8X rears forced me to stagger a much more aggressive pad up front, at which point, the brake bias is messed up when the car's cold and only gets comfortable after warming up.

Running the 370mm fronts with stock 300mm 525i rear brakes actually produces the correct bias... but I proceeded to melt PFC08 endurance pads into each and every dimple in the front rotor. The pad shape of the F3X/F8X caliper just isn't big enough for my needs. So I went to the E9X M3 caliper, paired to a 335i caliper carrier and 348mm rotor. Less sexy, but now I have my choice of Enkei wheels (they don't fit over 370's) that I can just beat on.

You can see it basically filling up the NT03 here.

016 by Brian Ma, on Flickr


The E90M front brakes are paired to E34 540i rear brakes now and bias is good, I like it - since E36M pads fit in the 540i caliper, I'm good on pad supply until kingdom come. Modernization and extensibility.

[moroza]

Welcome indeed! May Fakebook perish.

I buit an E34 544iT and DDed it a few years, now a 525iT with a GS6-37BZ (totally different mission than yours; I run a 3.07 rear). Did my homework on the latter and find your GS53BZ/M5x setup without an adapter plate most intriguing. Very curious about what it took to bolt them together.

[circuit.heart]

Welcome indeed! May Fakebook perish.

I buit an E34 544iT and DDed it a few years, now a 525iT with a GS6-37BZ (totally different mission than yours; I run a 3.07 rear). Did my homework on the latter and find your GS53BZ/M5x setup without an adapter plate most intriguing. Very curious about what it took to bolt them together.

Surprisingly straightforward. The bellhousing bolt pattern has two holes that are off by about 3mm each - a die grinder bit fixes this (curiously... the GS6-45BZ from the later S55 M cars has slotted holes here). The clutch requires some machining know-how, but not to modify parts - I bolted an M54 6-speed flywheel to the N54 clutch and aligned the trans to the flywheel by lathing an adapter "input nose" that plugs into the flywheel (where the M54's input shaft bearing usually lives). Using a JBR lightweight flywheel allows me to hold this "nosepiece" in with two screws, so no additional stress is incurred on the flywheel, it's purely a locating piece for the GS6-53's strange rolling bearing.

[danespann]

Hi, glad to see you finally putting this car on the forum. Lots of good development you've done for E34 track stuff.

[circuit.heart]

I guess it's time for a thread name change

After comparing M60 and M50 engine bays for a while, and realizing I'm having a kid soon, I chickened out and sold the M60B44 build. Going back to M5X means doing absolutely everything possible to keep it from blowing up though. Learning from the last few failures:

• New parts aren't always better than proven & checked old parts
• B30 cranks suck
• Stock crank dampers suck
• Forged pistons aren't worth much on OEM+ power output
• Upgraded water pumps will find weaknesses in your hoses
• Longtube headers are nice, but annoying
• S52 valve springs need thicker lower seats than M52 valve springs
• MLS headgaskets only
• Clean fuel injectors and flush fuel system before starting a new engine
• Check charcoal can and purge valve
• Don't lose oil pressure

Besides the obvious (going back to 2.8L displacement), I picked up some parts to resolve the above concerns:

• ATI crank damper
• Cometic headgasket
• PRD oil pump (similar to GSR motorsport M54 pump)
• Old, good, complete S52 valvetrain
• Standard metal-impeller water pump
• Ultrasound-cleaned 24lb Ford Racing injectors

I grabbed the old M52 from my friend's storage, brought it to Al Hubbard's machine shop for a check, deck, and hone, and got back a beautiful set of M52 basics with ancillary parts bagged and tagged. Great guys there. The weirdest part? I had them check the pistons since we saw evidence of detonation... but not only were the parts fine (cool), the entire rotating assy had actually been balanced at some point before I ever owned the engine. Cool

017 by Brian Ma, on Flickr


M5X oil pump failures being a meme at this point, I found this PRD/SLG pump for less than the cost of an OEM one. Screw it, bought.

018 by Brian Ma, on Flickr


The head had dropped 3 valves after the last fiasco, but somehow the valve seats, guides and seals were all still good.... ok, found new old stock of what I needed and got it from the UK.

019 by Brian Ma, on Flickr


ATI crank damper is insanely expensive for the amount of stuff in the kit. Cometic headgasket came in as well; I've had good luck with these in the past (most failures seem to happen when people don't prep the surfaces correctly...) but if there is a better brand in 2021 please let me know.


020 by Brian Ma, on Flickr

Also collecting parts for oiling. I won't be going over 1.6G lateral with the 525i so I didn't buy another Accusump, but Achilles was offering a good deal on their pan baffle and a Setrab core. S54 oil filter housing and a Bimmerworld adapter will be employed to plumb it up behind the headlight

021 by Brian Ma, on Flickr


There's a few more things coming in (stripped bolts and covers off an M50, new guides, tensioners and chains etc) and plenty of stuff I haven't been able to take pictures of, but I'm already getting excited to build another M52. It's gonna be smooth af with the ATI damper on a pre-balanced rotating assy.

[dannyzabolotny]

Stoked to see your car back on the track! It’s been way too long, gotta put all the E36’s and E46’s back in their place.

Regarding the oil pump, do you plan on installing an oil pump chain tensioner to help keep the pump alive, or will you just keep it below 7k?

[a777fan]

this whole thread

[circuit.heart]

Regarding the oil pump, do you plan on installing an oil pump chain tensioner to help keep the pump alive, or will you just keep it below 7k?

7k and below - none of the other parts of the engine (bearings, valvetrain etc) are rated for any higher anyways, so I am relying on low revs + ATI damper to keep the oil pump happy.

Now for something risky! I have been eyeing the Spec E46 Y-pipe for some time, since it effectively turns stock M52 headers (cheap, plentiful, flows well) into equal-length headers for a ~7whp boost.

022 by Brian Ma, on Flickr


Pictures of the prototype fitment suggest that it MIGHT just clear the K-member that holds our thrust arms:

023 by Brian Ma, on Flickr


So I ordered one just now, and we'll see if it fits in the tub. I specifically chose the E46 version over the E36 version Bimmerworld also sells, as it is longer -- so if it fits in the tub, it might actually clear my GS6-53 transmission without modification. Example pic from EatSleepTinker, I love how many SE46 guys document their builds/repairs/misadventures as it gives people like me fuel to do stupid things.

024 by Brian Ma, on Flickr


Fingers crossed!

[Singing6]

Took you long enough to get on here! Glad to see that the 53bz bearing adapter you bought back from me will be put to good use!

When you get the chance, please make a thread specifically on what you have learned with 53bz mounting to an m5x platform (like the dimensions of said adapter) so we can all benefit from it!

Also please test the spring weight of all the valve springs. Old may be gold, but no reason not to check that they are still within tolerance.

Interesting to hear about the upgraded water pumps blowing coolant hoses. I would personally still want to keep the Stewart pump due to the better bearing placement, and just underdrive it if it is a real issue, but you seem to have some levels of success.

Keep the project going!


Sent from my iPhone using Tapatalk

[circuit.heart]

99% of the engine stuff is here, time to build! As always there's something learned though, so I wanted to write this down in case anyone else winds up down the same path as me.

025 by Brian Ma, on Flickr


1) Since I'm racing, the machine shop opened up all the clearances - piston to bore, main journals, rod journals. One of the few failure modes for an M5X bottom end is bearing fail from insufficient oiling, so for sustained high-rpm fun, it makes sense to let the oil flow a bit more. Now it's up to the oil to maintain viscosity with heat. Something like 5W-40 or a thick 5W-30 should be appropriate, but I'm going to have to hook up an oil pressure gauge to know for sure.

026 by Brian Ma, on Flickr


2) WPC treated Glyco bearings (mains and rods) can be found cheaper than a vanilla set of Glycos, and it will tempt you. Tempted me WPC hardens the bearing surface however, so you extra extra can't have the crank touching the bearings. B25 (75mm) and B28 (84mm) cranks don't seem to have much issue with this but B30/32 (89mm) need to watch out.


027 by Brian Ma, on Flickr

3) CDI dial torque wrench is bad ass. My first time owning one of these, but all analog, +/-1% accuracy and no guessing when it'll click as you're watching the needle the whole time? What a great tool. 17ft-lbs then 50deg with washed and lubricated bolts for the main caps, made easy.

028 by Brian Ma, on Flickr


Printed a degree wheel off the internet like anyone else, man I've never gotten the crank in so fast.

029 by Brian Ma, on Flickr

[circuit.heart]

4) I don't know if Goetze rings are any good (the typical replacement you'd get from FCP Euro) but Mahle made my day with their packaging. "A" (oil scraper) "B" (2nd compression) "C" (1st compression) rings are bagged separately with the top side laser marked and the tips colored for easy spotting of the gap. Awesome. Positioning the ring gaps around the piston crown is pretty tedious, a dab of assembly lube helped keep mine in place.

030 by Brian Ma, on Flickr


Got the other WPC Glyco bearings into the rods, looking proper now.

031 by Brian Ma, on Flickr


5) Mahle rings come pre-gapped for the stock bore, if you hone the bore larger like me the ring gap will also increase by a hair. Not critical, good for safety factor on a race engine but the machinist warned me there would be a tradeoff at idle. Makes sense, so I'm sharing that in case you didn't know already.

6) I know people say the Hazard Fraught ring compressor is garbage - they're fine, you just need to flatten them against the block deck and re-tighten the ratchet before pushing the piston through. Didn't have a single hitch doing it this way.

032 by Brian Ma, on Flickr


7) ARP specs an unusual 47mm rod bolt for the US M52, but 44mm for the M50TU/S50US/M52Euro/S52US. I forgot to take a picture of this but my factory M52 rod bolt came out at 44mm (stretched). I don't think we need to worry about this, it's the same rod bolt between M52B28 and S52. So in they went, torqued to 40 ft-lbs as per ARP specs for S52.

033 by Brian Ma, on Flickr


This bottom end turns a lot smoother than even my last $$$ forged engine. A dab of WD-40 on the decked iron for now to prevent rust while I wait for cylinder head components to come in.


034 by Brian Ma, on Flickr

[circuit.heart]

Took you long enough to get on here! Glad to see that the 53bz bearing adapter you bought back from me will be put to good use!

When you get the chance, please make a thread specifically on what you have learned with 53bz mounting to an m5x platform (like the dimensions of said adapter) so we can all benefit from it!

Also please test the spring weight of all the valve springs. Old may be gold, but no reason not to check that they are still within tolerance.

Interesting to hear about the upgraded water pumps blowing coolant hoses. I would personally still want to keep the Stewart pump due to the better bearing placement, and just underdrive it if it is a real issue, but you seem to have some levels of success.

You had every chance to copy the input shaft adapter while you had it in hand

On Stewart vs HEPU, I dunno really. Both units seem to have a similar premature failure rate, so the dice roll is the same. The HEPU is much cheaper, and the works race teams never used any special pumps on their cars (I'm sure they were changed out regularly), so that's my gamble this time.

I bought underdrive pulleys for the HEPU pump, tbh. My car runs 27% higher rpm's than normal, but it's not like I make more heat (lower loading per gear + light car). Might need to use a fan on the street, but on track I'm not actually concerned. The poor car survived 4 sessions of balls-out hot lapping with a cracked radiator lol, it can't possibly do worse with a real cooling system


Misc updates: Bimmerworld Y-pipe has arrived, along with some nifty valve spring tools so I don't have to bug my wife to help hold the handle again.


035 by Brian Ma, on Flickr

036 by Brian Ma, on Flickr

[circuit.heart]

Cylinder head re-assembly. In the last fiasco this head had dropped two intake and one exhaust valve lol, I'm so glad I was able to find new old stock of these guys. Little bit of assembly lube and thanking my lucky stars that the valve guides were still in spec.

037 by Brian Ma, on Flickr


038 by Brian Ma, on Flickr


Valve springs are next. I had to order new S52 lower retainers (super hard to find used), but definitely not going to make the mistake of putting S52 springs on M52 lower retainers again.

039 by Brian Ma, on Flickr


The upper retainers and keepers are thankfully common. I've definitely fallen in love with the Metric Mechanic valve spring tool, besides needing to replace whatever garbage nuts they provided with the original ones that hold the cam caps.


040 by Brian Ma, on Flickr

Did this all myself in 45min, being suuuuuper slow and careful.

041 by Brian Ma, on Flickr


Now to find the oil pump bolts, clean those up and sink in the PRD pump!

[dannyzabolotny]

Awesome, can't wait to see this thing ripping at the track again! Gotta keep reminding all the 3-series elitists that the E34 is still capable of kicking some major ass on the track.

[a777fan]

[moroza]

I've got a lo-ve-ly bunch of valve springs, a deedily-deedily, there they are a-mounted in a row... boingaboinga-boing...

Speaking of oil, what oil are you using? Do you have any oil cooling systems in place?

[circuit.heart]

Awesome, can't wait to see this thing ripping at the track again! Gotta keep reminding all the 3-series elitists that the E34 is still capable of kicking some major ass on the track.

I think all the tissue boxes are the same at some point, it's just physics then driver mod. Because of gearing and tires, SpecE46 cars aren't even close, so it's not a fair comparison, but there aren't many other folks in my circles pushing NA non-aero 3ers to the limit. Once we're back it'll be running laps against NA M3's with aero, so if we can keep up, we win. lol

I've got a lo-ve-ly bunch of valve springs, a deedily-deedily, there they are a-mounted in a row... boingaboinga-boing...

Speaking of oil, what oil are you using? Do you have any oil cooling systems in place?

Oil is probably going to be 5W-40, but oil pressure readout will tell me if I can get away with 5W-30. A little bit of cooling is nice I think, but the car's so lightly loaded it doesn't need much. I plan on just piping air from the broken passenger fog light into a Setrab behind the headlight. Hidden, protected, short line lengths.

042 by Brian Ma, on Flickr


Speaking of oil, the PRD pump is super sexy, all primed up and installed. My dumb ass ordered the wrong length Iwis chain so I'm waiting till Thursday to install the correct one (and then, the oil pump drive sprocket and timing chain, timing cover, yay!).


043 by Brian Ma, on Flickr