What goes tic tic.......

[BchrisL]

BchrisL will happily work for you.

--John

The shop has to have a wood stove and an old bench seat out in front beside the coke machine!

[guitardad]

Me thinks' you missed your calling Chaz.

You need to open a shop.

Lord, no!!! I do OK when I can take my time. After all, it's been over a month since I started this job. But if I had to charge standard shop times, I'd starve!

[Bicyclist]

So, what kind of glue are you using to stick it together with? Are you using the activator?

[guitardad]

OK, I think I've made a mistake here. Check me on it....

I installed the rear main oil seal over the weekend. I don't have the special BMW tool for it, but used a trick from the MOA board to cut down a water bottle and use that to help slide the oil seal over the end of the crankshaft. BUT... I pressed the seal in until it stopped, which puts it about 4 mm recessed below the outside "lip" on the crankcase. Now, looking at the pics in the service manual, I think it should just be flush. And the wear line on the old crankshaft seems to say it should be flush.

So, did I press in the seal too far? If so, I'll just have to pull in and install a new one. Not too big a deal, but annoying, ya know?

[guitardad]

Three steps forward, and two steps back......

When I was last heard from, the engine case was back together and the rear main seal was going in. The new seal is different from the old, original one - it has less of a flat "face" and more of the ribbed flexible section that presses against the crankshaft. I started by carefully forming the flexible section to bend back into the engine case. New on the left, old on the right:



Now BMW has a special tool to install that seal, with a tapered section to help form it. You press the seal over the taper onto a mandrel, then remove the tapered piece. The mandrel matches the end of the crankshaft, so you just push it off the tool and into the engine. I'm not gonna buy a $150+ special tool, when a cutoff water bottle will do. (Cheapest part on a BMW and all that! )





For a drift, I found a PVC pipe fitting with just the right diameter - see how well it fits?



So I slid the seal down over the bottle and onto the end of the crankshaft, and then tapped it home with the drift. All the way home, see?



Button up the flywheel, using those one-time-only bolts torqued and stretched into place. Three steps forward. Then I realized - that seal should be sitting flush, not recessed back in the opening. Two steps back! Remove the bolts, and go buy new ones Pull out the seal, go buy a new one. Go thru all the steps again, but now the seal looks like this:



Now on to the cylinder heads. Anybody want to predict the steps forward and back for those?

[conanlloyd]

Just watch your timing on those heads. Just a bit off and yo can bend valves. (or so I hear, I wouldn't know myself)

[guitardad]

Just watch your timing on those heads. Just a bit off and yo can bend valves. (or so I hear, I wouldn't know myself)

Dude! Go look at my other thread! Do you remember how the arrows all lined up when you got the timing right?

[conanlloyd]

Just watch your timing on those heads. Just a bit off and yo can bend valves. (or so I hear, I wouldn't know myself)

Dude! Go look at my other thread! Do you remember how the arrows all lined up when you got the timing right?

Put this on the other thread as well but that is how I remember the good side looking. It's also how the other side looked after the new "unbent" valves were put in.

BTW, it clanked even when turning by hand when I F'd up the timing. When Mac was working on it at the Tech day you felt it hit on each stroke.

[guitardad]

Just watch your timing on those heads. Just a bit off and yo can bend valves. (or so I hear, I wouldn't know myself)

Dude! Go look at my other thread! Do you remember how the arrows all lined up when you got the timing right?

Put this on the other thread as well but that is how I remember the good side looking. It's also how the other side looked after the new "unbent" valves were put in.

BTW, it clanked even when turning by hand when I F'd up the timing. When Mac was working on it at the Tech day you felt it hit on each stroke.

Got it! I've turned it thru numerous times, and there's nothing hitting, no "bad" noises, no extra reistance near TDC. So I'm feeling OK enought to have buttoned it all back up. I've got an "imaginary friend" in Wisconsin who rides a '94 RS, so I asked him to go out and look. Hopefully he can confirm this alignment.

[guitardad]

Fell behind in my posting - sorry! But as I said, on to the cylinder heads! Boxer cylinders are simply jugs that slide down over the studs threaded into the case - like this:



Just like on Hans, I left the piston in the cylinder. So reinstalling the cylinder just means sliding it in place and installing the wrist pin to mate piston to connecting rod. Note the dexterity! Also note the chain for the camshaft, which was pulled taut then rubber-banded to the guides as I put the cases back together. (In English class, this was called foreshadowing...) Next step is a new head gasket, then the cylinder head goes on:



Hardest part is to put the sprocket for the camshaft into the chain, line it up properly, and keep it there as the head is slid into place.




Now remember, everything has to be just right. Crankshaft and aux shaft lined up with the marks aligned. Chain taut, and the camshaft sprocket aligned. Here's where my next problem arose - the marks on the sprocket didn't match exactly the way my manuals said they should. I'm worried enough to stop and ask for help. Remember this? But on advice from Anton and others, I used the keyway to align the sprocket properly. For the right cylinder, it should be straight down - and you can see in the pics above that it is. So from the front, everything looks good:



One down, one to go. I spin the engine 360 degrees, and repeat on the left cylinder. I have to take the rubber bands off that keep the chain taut, and hold it by hand as I turn the engine over. And I hear some "clattering" noises as it turns, but figure that's not a big deal. Guess what? It is. The chain won't quite reach the camshaft! I pull and tug, I pull the cylinder off so I can adjust the guides. No help at all. Then it dawns on me - the chain probably has one "slack" link, down on the aux shaft sprocket, and that's what made the chain "too short." That's also what made those clattering noises. Two steps back - I have to take it all back apart, split the cases again, get the chain back in place and REALLY hold it taut as I close everything back up. Pam helps hold chains in place this time and I get it back together properly. Till we end up here:



The engine turns over smoothly by hand, with no bad noises or valves hitting the tops of pistons. Three steps forward - finally!!!!!

[Unity]

Two steps back - I have to take it all back apart, split the cases again, get the chain back in place and REALLY hold it taut as I close everything back up.

You say this so calmly.

--John
(Lookin' good, Chaz. What's your ET for first test ride?)

[guitardad]

I'm hoping to go around the block before this long weekend is over. But the cam timing questions set me a little behind schedule, so we'll see........

[Dough Boy]

I am continually impressed by the Chazster.

MuffinMan brings the tech prowess.

[Rick F.]

Two steps back - I have to take it all back apart, split the cases again, get the chain back in place and REALLY hold it taut as I close everything back up.

You say this so calmly.

--John
(Lookin' good, Chaz. What's your ET for first test ride?)

Chaz (& John),

+1

I doff my cap regarding your willingness and ability to dive into a complete engine disassembly. I've rebuilt several car engines, but the intricacies of a BMW boxer engine appear awfully daunting.

Best of luck with the rest of the process!

Rick F.

[BKling]

Agreed, what they said.

I love taking things apart, it's the putting back together.

My hat is most definitely off to you Chaz.