Non-BMW Stuff on a BMW Forum

[gilber33]

Has anyone done a removable core support on their e30? As I get ready to pull the engine for the 3rd time to check the clutch and to put in the rebuilt m20, a removable core support sounds awfully tempting.

[Jdesign]

gilber33 said:

Has anyone done a removable core support on their e30? As I get ready to pull the engine for the 3rd time to check the clutch and to put in the rebuilt m20, a removable core support sounds awfully tempting.

I think @Sam_Holzmann has?

[KaiserRolls]

Jdesign said:

I think @Sam_Holzmann has?

Didn’t @GunMetalGrey make one as well? 

I also would like to do this lol

[gilber33]

Well if any one can chime in with some pointers or if it's worth the work that would be greatly appreciated.

From what I could dig up it doesn't look like there's one way to do it and you kinda have to dive in, cut it out, and then figure it out from there.

[KaiserRolls]

gilber33 said:

Well if any one can chime in with some pointers or if it's worth the work that would be greatly appreciated.

From what I could dig up it doesn't look like there's one way to do it and you kinda have to dive in, cut it out, and then figure it out from there.

blast from the past

[gilber33]

KaiserRolls said:

blast from the past 

winner winner chicken dinner. Thank you! This doesn't seem too bad.

[GunMetalGrey]

Two suggestions

#1 Use rivnuts on the chassis side to bolt the core support back in with. It's handy as hell
#2 Make sure to slice things to you can remove your core support without needing to pull the fenders. 
#2.5 Have a couple beers, slicing into your core support feels like it should be more calculated than it really is, and a little grinder operation lubricant never hurts. 

I used a new core support because mine was bent, so I had the luxury of truly destroying it.

[gilber33]

I was planning on using rivnuts. Seems much easier than welding nuts for bolts. 

I would much rather cut it out without having to pull the fenders. I assume that if I am slicing it so it can ultimately be removed without needing to pull the fenders I shouldnt need to pull the fenders off to do the initial cuts? 

I will make sure the mini fridge in the garage is stocked before I start cutting.

[gilber33]

Hey guys- so what am I looking for to check both the universal joint on the driveshaft and the CSB? The driveshaft is out for inspection.

[B C]

The joints need to move smoothly with no grit, binding, or increase in resistance. When you grab the yoke and the shaft and check it for freeplay, there should be none.

CSB should have no cracks in the rubber and the bearing should be tight and quiet as it rotates.

[gilber33]

Got the block back today after a hone. Started cleaning up the pistons. One is kinda done and two others are soaking in carb cleaner for the night. 

[B C]

In regards to the two connectors Chris identified,  the first 2 things to check when an M20 isnt starting after a teardown is

1. did the fuel lines get swapped?

2. did those two connectors get swapped?

IMO Cleaning up an engine is the most satisfying part of wrenching.

[gilber33]

Crank and new main bearings is in and the pistons are all cleaned up. 

Doing the crank was way easier than I assumed it would be. Which always makes me feel like I did it completely wrong. 

[gilber33]

After doing some more reading, I’m going to pull the crank back out to clean the bearing seating surfaces a little more thoroughly on the block and caps. And then reinstall the bearings and crank. Better safe than sorry.

[gilber33]

Redid the crank bearings last night and I’m glad I did. I didn’t clean it as thoroughly as I could have before. Cleaned all the piston rings grooves and started measuring ring gaps. 

The Bentley Manual calls for a .012 - .020 gap and all the rings came in at .013 on the first two cylinders. Looks like I might be able to get away without having to do any filing.

[jc43089]

gilber33 said:

Redid the crank bearings last night and I’m glad I did. I didn’t clean it as thoroughly as I could have before. Cleaned all the piston rings grooves and started measuring ring gaps. 

The Bentley Manual calls for a .012 - .020 gap and all the rings came in at .013 on the first two cylinders. Looks like I might be able to get away without having to do any filing. 

Did you check clearance with plastigage?

[gilber33]

Nope. In my mind, if it was fine with the old bearings in there before, it’s going to at a minimum be better with new ones.

[GunMetalGrey]

gilber33 said:

Nope. In my mind, if it was fine with the old bearings in there before, it’s going to at a minimum be better with new ones. 

Not that I haven't done the same, but from a manufacturing standpoint this is terrible logic. 

I'm glad you get to avoid filing rings, that's a tedious task that usually requires a spare ring or two!

[gilber33]

GunMetalGrey said:

Not that I haven't done the same, but from a manufacturing standpoint this is terrible logic. 

I'm glad you get to avoid filing rings, that's a tedious task that usually requires a spare ring or two! 

I knoooowwwwww. I guess I can check the clearances. I’ve taken back apart once. I know you’re supposed to do it it dry but I’ve already lubed it up. Will I be fine taking the crank out and wiping down the bearings to remove most of the oil? 

Also, can anyone confirm that the bearing clearance should be between .03-.07 mm?

edit: bought some plastigauge. I’ll pull the crank off and wipe down the bearings and measure the clearance section.

[gilber33]

Pulled the crank back out tonight, cleaned off the bearings, put it back in with plastigauge.

.038 across the all 7 caps. Very healthy. At least I know now. Also got three pistons ready to go in.