Sad news on project Chicago, the Alpina B7 (Patreon)

First of all, I want to thank all of you for being here! Since the last video, we gained more Patreons and many upped your level, thank you from the bottom of my heart!

Now onto the bad news. Right after I posted the last video on here, I went to the shop to unload some of the parts that arrived. I had some time to kill and decided to look inside the cylinders with the endoscope, something I haven't done before, but should've. 

When I got invoices from the previous owner, I was already tearing apart the engine and that's when I saw the invoice where the shop in Texas did leak-down and compression test. Results were good but cylinder 7 was weak, they cleaned it and got it within spec. I was curious to see what that cylinder looked like, so I went inside with the camera and it looked okay, no damage. I briefly looked at another cylinder on that side, also looked okay and I continued tearing apart the engine. 

So this time around, I started with cylinder 1 which was at TDC so couldn't see anything. Cylinder 2 good, cylinder 3 good and then when I got to cylinder 4... my heart sank. You can see pictures with the endoscope above. That's what a properly scored cylinder looks like.

I just couldn't believe it, the engine sounded beautiful, no smoke from the exhaust or any signs of mechanical issues with the engine. Needless to say, complete oversight on my part, I should've scoped the cylinders immediately, but I honestly didn't even imagine something likes this would be inside given how well the engine worked, the spark plugs were nice color and no smoke from the exhaust.

On the bright side, luckily I caught it when I did. If I reassembled the engine and then learned about this, that would've been a disaster because this engine wouldn't last long.

After learning this, I decided to pull the engine out of the car, remove heads and inspect the block closer. I actually got it out with the transmission relatively quickly.
Popped the heads and sure enough, nice scoring in cylinder 4. It looks worse than it actually is, the scratches are not too deep but you can definitely feel them under your finger.
Cylinder 2 has a bit deeper scratches at the top and then I turned over the engine and saw cylinder 1. Also scored similarly to cylinder 4. The rest look more or less okay.

In its current state, this engine is dead. This is an aluminum block coated with alusil. Very difficult to repair properly. The block is Alpina specific, I checked the price for a new one from Alpina and just the block is 5.000€. Which isn't horrible compared to high-end cars, but that would be just the start of it.
Tomorrow I'll inspect the crank, but if I were to do a full rebuild, I'd want new eccentric shafts, possibly cams, Vanos units, rod bearings, piston rings and maybe even pistons if they are in bad shape... It just doesn't end and the cost for parts alone would easily exceed 10.000€. 

And that, that's a lot of money. So I'm not sure what's going to happen. Once I fully strip the block, I'll do rough math to see how much it'd take to rebuild the engine completely and if it makes financial sense. If I decide to proceed, I would likely need to sell one of the cars in order to finance this rebuild and I really don't want to do that. Selling a beautiful E30 to fix shitty N62 just seems so wrong. 

On Monday, I'll take the block to a nearby specialist shop. I already sent pictures to them and they say the block might be repairable, but I don't have high hopes. Alusil is very difficult to repair and I'd have a hard time trusting someone they could do it 100% properly. 

It's not looking good, but I'm not giving up yet. Video on this will come soon, until then keep it to yourself. :)

Love you all!