szacsi72's 1984 Zinnoberrot 535i Build

[1st 5er]

I'd rather have an actual mechanical problem than this black magic that some call electricity.

[adam_poll]

Just get the fancy, shiny, forged pistons. You'll feel better knowing they're in there

[szacsi72]

I'd rather have an actual mechanical problem than this black magic that some call electricity.

This stays true, I'm still rather pulling the engine than hunting down a miracle ground fail

Just get the fancy, shiny, forged pistons. You'll feel better knowing they're in there

Oh, I definitely would feel good.. before the woman finds out where the money went that was meant for our new fence...

[szacsi72]

No progress on the engine rebuild etc, but at least my new billet steel flywheel got delivered earlier this week!


It weighs roughly 6.1kgs.

[szacsi72]

Removed the old master cylinder, as the new E32 unit has arrived. This was a "why not while at it" mod for me, as I didn't really felt the need but it turned out to be a good idea because my original unit was already leaking.



And for some extra, I've just found out that my clutch MC is also leaking. Ordered a new one..

[szacsi72]

In case anyone is still following this thread.

I have not posted for a while and probably won't post much for some time either.
I've had a surgery that went horribly wrong and got some serious lung damage & radiation poisoning. I'm unable to perform 95% of basic tasks as of now, the doctor said I'll take at least half a year to recover.

In the meantime, my gearbox is stuck to the engine. I have removed every bolt, removed the started, master cylinder, etc. I tried moving it up and down with a floor jack, and prying it lightly. There is now a 1mm gap, so I'm 100% sure it's not connected but it's not coming off.
The transmission I believe is currently in third. Could that be an issue? Did they just rust together?

Thanks for your input.
David

[Galahad]

Geez, I'm sorry to hear that - health problems are big issues.

I had a gearbox stuck to an engine, had to use a bunch of bolts to press it off. The end of the input shaft had rusted and gotten stuck in the pilot bearing, I broke the clutch disk during removal.

Best of luck with recovery!

[Foonfer]

oooh man, that sounds awful. Hope you make a good recovery. Radiation poisoning is no joke, don't let it go unattended.

[1st 5er]

Praying for a quick recovery.

[jimoreno]

Hope your health issues get resolved soon and to your benefit.

[szacsi72]

Thanks for the support guys. I'm a bit better now, I can walk and eat and whatnot, just don't have any power - both physically and mentally - but my friend is coming over tomorrow to help a bit, so that the project can continue. I'll need to wait quite a lot for the machine shop Anyway, so I really want to at least get the engine block and cylinder head there..

[Mdreamer]

I'm also wishing you a restful and full recovery.

[szacsi72]

Thanks Mdreamer!

So my friend came over on Saturday, and "helped me" (read: did everything while I observed.) Here are some updated.

1. Good news: All the pistons, and rings came out undamaged. So my fear of having broken rings or damanged pistons is gone. There's some wear, and minor scrape on all pistons. I will measure the cylinders and pistons next week and see how bad the wear is, and continue after I've got the data.
I'm also considering coating them with Cerakote C110 and C186. I don't think it would gain much, I'm mostly just interested in the technology, + the skirt coating could help with the minor wear and scrathes. We'll see!


2. news: we removed the clutch and flywheel and had quite a surprise. When I bought this powertrain - engine to transmission - I was told "resurfaced, double mass flywheel, with a new sachs clutch".
Well, the flywheel wasn't resurfaced, apart from some angle grinder signs... , the clutch wasn't new and it wasn't a double mass. Which would normally make me happy, since I got a single mass flywheel, BUT it's basically trash. And I wondered why it felt a bit odd and a bit shakey...

I forgot to take a picture of the clutch disc, but it's a non-sprung one. Well, that explains some unwanted noises... and while it shaked when pulling out of first gear. And I tried to blame the driveshaft.. into the trash it goes. New clutch and flywheel are waiting for me anyway!




3. bad news: cylinder #4 had a conrod bearing failure. Yet again, I forgot to take a picture, which I will make up for later. But it's worn down to the copper/bronze base, and when fitted without the crankshaft, I can visually see that it's oval and bent. AND YET, the crankshaft is in perfect shape.
Maybe the head gasket issue wasn't that bad after all, or else, I wouldn't have pulled the engine. I really don't know how I did not notice this, I had oil pressure, and there was no knocking sound at all.
Anyway, I'll measure and polish the crankshaft and get new bearings.

I'll disassamble the cylinder head when I have some time - and when I feel better, then the head and the block are off to the machine shop! Both will be skimmed for higher compression ratio, and the block will recieve a clean-up honing.


4. This is just interesting: I yet again got SUPER LUCKY! Do you see anything missing here? No? Yes? Welp, I've lost the king nut while driving. Luckily, nothing was sent to the sky... this could've ended badly!
I'll NEVER install anything again without checking every single bolt and myself.




Until next time!

[jimoreno]

That's a VERY clean engine bay!
Love the way it looks.

[szacsi72]

That's a VERY clean engine bay!
Love the way it looks.

Thanks, I'm about to destroy it. There's some paint damage here and there, one spot has some minor rust, there's some cracks - looks good, but bothers me in person - I want every part to be perfect, so I'll respray it! I'm also installing new brackets for the hood struts, since mine were previously deleted, and there's already plenty of bumps on my head.

[szacsi72]

While the components I need to continue with the engine build are on their way, I've decided on the interior.

Black headliner ✓
Red seatbelts ✓
Red stitching ✓
Red gauges/needles ✓
Black plastics ✓
E34 sport seats ✓
And the last piece of the puzzle:
M-Rain cloth fabric for the seats with black sides and middle for the rear seats; and also M-rain for the door cards.

I think it will match nicely.

[szacsi72]

I'm feeling better and better, so todays program was measurements.

I removed most components from the cylinder head to prepare it for the machine shop, and measured the piston and cylinder wear to see if I can reuse them.

Before I get going with that, here are the pictures of the rod bearing on cyl4. As you can see it's really worn, and even deformed. I'm not sure how, and why only cyl4 is like this, probably lack of oil from a blocked oil path? Possibly. I will never know, but this engine did NOT live an easy life, that's for sure, and you'll see soon as you scroll....






Surprise #1:
I was looking at this piston and something was odd. I looked at the other pistons and noticed that only this one had a relief cut for the exhaust... wait! That's not a relief cut! Someone lost a valve before me... must have been a different head, the valve looks intact.




Surprise #2:
As I was disassemblying the head, I finally had a good look at the camshaft. I knew that there was quite some wear on cyl1, (the rest are barely worn - maybe it had a banjo fail somewhen..), but I didn't expect it to be this bad. The wear on cyl1 exhaust lobe measured exactly 0.6mm, which means roughly 0.8mm in lift. No wonder it idled like it had a hotcam..




Surprise #3:
There was one spring that was different to the others. It was much stiffer. I don't think it would have caused any issues, but I'm glad I caught it. Probably doesn't help with wear!




Surprise #4:
I've never seen an original BMW rocker this worn. This one is cyl1 exhaust, the one that had the wear on the camshaft, so it's understandable..:



But this one is even worse, this is cyl5 intake. The camshaft is barely worn, or damaged! No idea how this happened but I think probably this head (and the whole engine basically) was just thrown together from random components they had laying around... I guess it shows. It lived 5000kms-ish.





Wear on the eccentrics was quite normal:





That's all for the head now. Needed to see what I'm dealing with - time to measure!





There was some scoring (scuffing?) on all 6 pistons, but neither of them looked too bad and they aren't too deep. Almost all older M30 pistons look like this, so I'm not too worried (but let me know if you think otherwise!), probably a lot of cold starts.


I won't bore you with the process, here are the numbers:




Regarding the pistons, I'm quite satisfied. On average, I'm at 40% of their life based on the 0.15 "wear limit". Good for another... who even knows how many kilometers... a lot of.
The cylinder wear isn't too bad either, but the sides appear polished and I can't see the honing marks, so it's far from new. Unfortunately, I'm just over the limit... BMW states that out of roundness should be 0.01mm max, and multiple cylinders measured in at 0.015mm.
Cylinder taper is good, not out of the limit anywhere.

Based on these values, I'm considering asking my machinist to hone my cylinders to 92.04mm.
I would still be within reasonable clearances (0.15mm service limit for the piston, remember), but it would remove the leftover taper and out of roundness. Plus, it needs a cleanup and re-hone anyway...

Guys with M30 experience... Let me know what you think!


I'll talk about compression ratio and how much I want to deck the parts in the next post...

[szacsi72]

So, regarding the compression ratios.

My plan is to basically up the compression, as I will be running a medium-hot cam, to have a higher than original dynamic compression ratio. I don't want the engine to react sluggish at low RPM - which is something that I've seen happen with the combination of a hot cam and low compression.

I also measured out the B35 Alkan pistons to have a dome volume of 6.6cc.
Interestingly enough (I still can't get over this) the values I get are higher than the stated BMW values. Either the head CC is wrong, or BMW lied.



Anyway, I measured my cylinder head to be 128.8mm and the block to be 217.4mm.
My plan is to shave off 0.3mm from the head (to be at -0.5mm from the original of 129.0mm), and the block 0.2mm (to be at -0.3mm of the original of 217.5mm).

This should give me a dynamics compression ratio of 9.03, while the original is 8.74.
I will probably need to mill the pistons for the valves...

[Tiit]

Very interesting.
What are the cam specs and what's the new CR?

[szacsi72]

Very interesting.
What are the cam specs and what's the new CR?

Cam specs are:
KMCams Steg 2
290°/290°, 10.2mm/10.2mm, 110°/110°
https://kmcams.com/products/bmw-735-528 ... m30-steg-2

The new static compression ratio is just a hair under 10.0:1.

[Tiit]

Cheers. Looking forward to future updates.

[szacsi72]

Cheers. Looking forward to future updates.

It will hopefully come soon! I will try to detail the engine build as much as I can

[szacsi72]

Had some time to completely disassemble the head.
The goal is to do all the modifications now, so once it's back from the machine shop, I can clean it and install it, without worrying of particles and/or damaging the surface.
I re-tapped every thread to clean them up, and sanded all the mating surfaces with 400grit. Prior to that, I soda blasted the whole head to make my job easier.




Now that it's empty, I can prepare for the head porting. I'm not doing anything crazy - no need to reinvent the wheel. The most important thing is port matching the intake manifold. The gasket is 95% accurate compared to the actual head port, so you can see that there's quite some material that needs to be removed. In some areas, the lip is as big as 2mm... To help with the porting, I scanned the gasket, and drew the new port shape I'm looking to create.


upload pic


Apart from that, I'll just smoothen out the ports with 120 grit on both sides, and blend in the guide a bit more.

However I don't know what to do on the exhaust site. The headers I bought have a larger than stock port, which means that if I want to take advantage of that - and match the cylinder head port to it - I'll need custom, bigger port gaskets. That's not a problem, but then I'd loose the heat shield. So I guess I'll need to make a custom heat shield too, that I'll mount OVER the manifold - not under, like the stock one.
It's not the end of the worlds, just a bit more work that I don't want to do, this build it taking forever already Anyway.

As I could not start with the porting but still had some time, I took a closer look at the KMcams rockers. They are gas nitrided, which leaves the surface finish a bit dull. KMcams states that it's fine, and I can see why. This is after roughly 30 seconds of polishing with a car paint polishing compound. It's nice underneath, and the coating will probably come off in the first 15 seconds when the engine is finally started...




Of course that doesn't stop me from pre-polishing them. I'll get some 2000, 4000 sanding blocks and hit every single one of them, then some polishing compound. I'm doing this because in my head, I have this idea that this will help with the break in - I hope for a smoother initial finish on the cam - the materials from the dull finish will go somewhere! Either into my oil, or onto my camshaft. Don't want neither!
Second, I hope this will help minimize the valve gap enlarging, so the valve train won't get too loud too quickly, before I do my 1000km valve adjustment.


And of course, parts are slowly but surely being collected... I want every single piece laying on my desk before I start the assembly.

[gwb72tii]

I love reading about your engine build. And super sorry to hear about your health setback.
Wishing you the best recovery, and the best with the motor and car.
It’s always a moment of truth when you start a motor you’ve rebuilt, wondering if every bolt was torqued, did I forget anything etc.

[szacsi72]

I love reading about your engine build. And super sorry to hear about your health setback.
Wishing you the best recovery, and the best with the motor and car.
It’s always a moment of truth when you start a motor you’ve rebuilt, wondering if every bolt was torqued, did I forget anything etc.

Thank you. It took a good turn, I'm recovering very well. Physically, I'm pretty much recovered, apart from wound on my head, that I need to watch out for; and of course, I've lost a lot of body weight, so I'm very weak. But it's getting better.
Mentally I'm fine, just constantly tired. I forget too many things, make mistakes and I'm slow. So therefore, I'm also not back to work yet. It would not be fair to ask for my wage and only do 50%.