Musings from the shop
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I pulled a sting to see how straight the driveline was going to be. It's attached to the diff flange in the rear, and I used the height of the output flange of the transmission to set the height of the string at the front of the car.
I put a pipe across the frame rails so that I'd have something to measure off of after I put the engine and trans in.
Whoa... that's not good. The front of the engine about an inch and a half low. Not a huge angle, but enough that I think I'm going to make a new transmission crossmember to compensate.
After I was happy with everything I welded up the crossmember and bolted it up to my mock-up engine. It's been a long time since I did any welding, but it turned out pretty good.
I was going to work on mounting the center support bearing today, but I forgot to order the the little dust shield that goes on the driveshaft, so I put some candy-colored bushings in my LCAs instead.
Making progress, and it feels good.
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Ah... hard to say. Still have some work to do in the bay before I can paint it. The block is still at the machine shop waiting for pistons. Hopefully they will come this week. Then reassemble the engine, put it in the car, wiring, exhaust, fuel pump and lines, 10 other things that I forgot about and will probably have to wait on parts for.... hopefully early May? Late May is probably more realistic though.
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Nice!
I've been in a bit of a lull lately. Took me a few tries to get the center support bearing mounts for the e30 driveshaft done right. I finally got my pistons and dropped them off at the machine shop. Hopefully I'll have the block back by next weekend. It's been a long time since I made any visible progress, so I decided to put the front suspension back together and put the car back on the ground.
I wheeled it outside and rinsed a couple months worth of accumulated dust off of it and now I'm totally stoked about getting it back on the road again. Spent a few hours today scrubbing down the engine bay. Will probably put some paint on it this week.
This is what I like to see. A small forest of unused jackstands!
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Gloss Mother F****** Red and Gloss Mother F****** Flint Gray Metallic makes for one Hip Mother F*****
Surprise mother f*****
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Okay, so here's my engine rebuild timeline so far...
March 3 - Ordered JE pistons through Top End Performance. Estimated 3-week lead time.
April 15 - Received pistons.
April 16 - Dropped pistons and block off at Automotive Supply to have the block bored. Was informed that they had gotten busy so it might take a week or two for them to get it done.
May 5 - Voicemail from Automotive Supply asking me to call them back.
May 6 - There was a problem with the tooling (or something...) and my block is wrecked. Agreed to sell them the other block that I had. Dropped 2nd block off the same day.
June 3 - Received voicemail that my block is done.
June 4 - Picked up block. Hone job looked like shit. Put a ring in each bore to measure the ring-gap and 3 of the bores were tapered. The tops of three bores were ~.002" undersized, but the middle was the correct size. The forth bore was .002" undersized with no taper.
June 5 - Brought block back to Automotive Supply. Jason, the "machinist" was off so I'd have to wait until Monday to talk to him.
June 8 - Stopped at Automotive supply to find out what he was planning to do with my block. He hadn't looked at it yet, but said he'd look at it and call me later that day.
June 10 - Having heard nothing I went back to find out what was going on. They said it was done and gave me my block back. The bores are a fuzz larger and no longer tapered, but one bore is ~.0025" larger than the other three.
TLDR: It took Automotive Supply 2 months to bore a block, they destroyed one of my blocks in the process, and they did a shitty job. Not recommended.
First time I got it back. Aside from the "crosshatch" there was a lot of horizontal marks. That combined with the taper makes me think that they probably didn't bore it at all, but just hogged it out with a hone. Vertical lines are from the bore gauge.
It looks a little better now, but still not good.
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I don't know the specifics of this particular bmw block in terms of the outer limits of boring out, but I personally would not be comfortable with a difference like that. Engine building is a precision exercise, plain and simple. You need a shop that's gonna measure and check to a tee. Anything less is risking premature engine failure. If you use what you have, you're going to have to re-calculate your expected compression from the bigger bore on one cylinder and build around that (depending on your performance plans), and higher risk of cylinder wall failure depending on the tolerances of the block (again, I'm not aware of the specifics on your motor). But these are generally things I would be worried about. If one cylinder isn't to proper spec for the JE pistons you're using, the larger bore is going to be a higher risk for blowby and premature wear on your ring and bearing in that cylinder.
i dunno. I just don't like there to be anything inconclusive about my block before I put it back together.
2011 E92 M3 6MT ZCP - ESS 625 supercharged
2007 Z4MR
2003 E39 M5
2002 E46 M3
2021 X5 40i -
I agree that it's far from ideal, but I want to actually drive the car this summer. Specifically I have a vacation planned for mid July, so I'm in a hurry to get it done. I'm also renting shop space, so every month that the car sits there is more money out the window. Worn out cylinders can easily have .005" of wear, sometimes substantially more, so basically I'm starting my rebuild with one bore that's half worn out. It suck, but given the circumstances, I'm just going to deal with it. As long as the pistons don't get wrecked I can get a new block and do it right next year.
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