carmudgeons.com  

Go Back   carmudgeons.com > Automotive Forums > Technical Superiority

Reply
 
Thread Tools Display Modes
Old 05-26-2021, 09:09 PM   #21
JST
195
 
JST's Avatar
 
Join Date: Oct 2003
Posts: 23,521
Damn. Aren’t they just…pieces of metal? Wtf are they made of?
JST is offline   Reply With Quote
Old 05-26-2021, 09:50 PM   #22
Nick M3
Relic
 
Nick M3's Avatar
 
Join Date: Oct 2003
Location: Bethesda, MD
Posts: 11,847
well, according to my shitty calipers, the #3 journal is a little less than .2mm out of round. so *definitely* not going to be just slapping new rod bearings in. bearings are available in .25 and .5, so hopefully it can be cut to .25.

It was pointed out that if I need to, the S54 crank is an option.
__________________
2011 M3
2006 Sierra 2500HD 4WD LBZ/Allison
2004 X5 3.0i 6MT
1995 M3 S50B32
1990 325is
1989 M3 S54B32

Hers:
1989 325iX
1996 911 Turbo


Nick M3 is offline   Reply With Quote
Old 05-27-2021, 01:23 PM   #23
Nick M3
Relic
 
Nick M3's Avatar
 
Join Date: Oct 2003
Location: Bethesda, MD
Posts: 11,847
Good news! Further searching found the Mahle ring kit. Which is the OE part. For about 20% of the BMW cost. So that’s back on the table.
__________________
2011 M3
2006 Sierra 2500HD 4WD LBZ/Allison
2004 X5 3.0i 6MT
1995 M3 S50B32
1990 325is
1989 M3 S54B32

Hers:
1989 325iX
1996 911 Turbo


Nick M3 is offline   Reply With Quote
Old 05-30-2021, 07:45 AM   #24
Nick M3
Relic
 
Nick M3's Avatar
 
Join Date: Oct 2003
Location: Bethesda, MD
Posts: 11,847
Got the engine broken down yesterday. Aside from the rod bearing, it looks fantastic inside.

I’ve been hunting around for a replacement crank, but it seems pretty likely that i’ll need to get this one repaired.
Attached Thumbnails
Click image for larger version

Name:	7E126952-6F43-41E9-BD73-D0AC40FB29A4.jpg
Views:	181
Size:	1.44 MB
ID:	13454  Click image for larger version

Name:	63DEF41E-F4D6-478F-99F9-B0154EBC310D.jpg
Views:	180
Size:	1.72 MB
ID:	13455  Click image for larger version

Name:	DDCF41F5-CC34-4687-ADBA-DB62406D129E.jpg
Views:	177
Size:	1.58 MB
ID:	13456  Click image for larger version

Name:	5C2F3752-FFDD-44A7-BD23-E54EA0C01F41.jpeg
Views:	175
Size:	578.6 KB
ID:	13457  Click image for larger version

Name:	C536ED28-C67B-4989-A839-A35A953340DF.jpg
Views:	181
Size:	1.41 MB
ID:	13458  

__________________
2011 M3
2006 Sierra 2500HD 4WD LBZ/Allison
2004 X5 3.0i 6MT
1995 M3 S50B32
1990 325is
1989 M3 S54B32

Hers:
1989 325iX
1996 911 Turbo


Nick M3 is offline   Reply With Quote
Old 05-30-2021, 09:02 AM   #25
JST
195
 
JST's Avatar
 
Join Date: Oct 2003
Posts: 23,521
You mentioned the S54 crank up thread—is that not viable?
JST is offline   Reply With Quote
Old 05-30-2021, 10:04 AM   #26
Nick M3
Relic
 
Nick M3's Avatar
 
Join Date: Oct 2003
Location: Bethesda, MD
Posts: 11,847
Quote:
Originally Posted by JST View Post
You mentioned the S54 crank up thread—is that not viable?
I know it’s viable. I’m just not 100% sure about which running gear is needed to make it work, and the cost / time equation on that is probably not better than fixing this one.

In particular, the S54 crank requires S54 rods (no biggie - I have to replace the rods anyway), but it also requires S54 pistons. Which creates some extra work as I’d have to bore the block.

Now… I haven’t checked the cylinder bores yet. If they’re off and the block needs to be bored, then that changes the calculation.
__________________
2011 M3
2006 Sierra 2500HD 4WD LBZ/Allison
2004 X5 3.0i 6MT
1995 M3 S50B32
1990 325is
1989 M3 S54B32

Hers:
1989 325iX
1996 911 Turbo



Last edited by Nick M3; 05-30-2021 at 10:31 AM.
Nick M3 is offline   Reply With Quote
Old 05-30-2021, 11:16 AM   #27
JST
195
 
JST's Avatar
 
Join Date: Oct 2003
Posts: 23,521
Is the s54 block the same as the s50 in other respects? Just slightly different bore (and stroke?) or is it totally different?

Also this is your reminder to buy at least one spare S54 now and pack it in Cosmoline, while they are still cheap.
JST is offline   Reply With Quote
Old 05-30-2021, 01:12 PM   #28
Nick M3
Relic
 
Nick M3's Avatar
 
Join Date: Oct 2003
Location: Bethesda, MD
Posts: 11,847
Quote:
Originally Posted by JST View Post
Is the s54 block the same as the s50 in other respects? Just slightly different bore (and stroke?) or is it totally different?

Also this is your reminder to buy at least one spare S54 now and pack it in Cosmoline, while they are still cheap.
Identical stroke (crank driven), slightly greater bore. S54 pistons require a little bit of alteration to the skirt in order to clear the S50 oil squirters. And, I believe, 0.5mm overbore.

The reason why I can’t just drop in an S54 crank is that the rod journals are too narrow.
__________________
2011 M3
2006 Sierra 2500HD 4WD LBZ/Allison
2004 X5 3.0i 6MT
1995 M3 S50B32
1990 325is
1989 M3 S54B32

Hers:
1989 325iX
1996 911 Turbo


Nick M3 is offline   Reply With Quote
Old 06-01-2021, 02:54 PM   #29
Nick M3
Relic
 
Nick M3's Avatar
 
Join Date: Oct 2003
Location: Bethesda, MD
Posts: 11,847
So... Talking it over with a machinist friend, the S54 crank may be back on the table. It looks like the width of the small end of the rod doesn't really matter, which would let me put the S50 pistons on S54 rods on the S54 crank.

Which would give me a convenient drop in solution.

And speed has real value, given that I have maybe 6 weeks to get this done, or else it's probably going to sit for a *while*.
__________________
2011 M3
2006 Sierra 2500HD 4WD LBZ/Allison
2004 X5 3.0i 6MT
1995 M3 S50B32
1990 325is
1989 M3 S54B32

Hers:
1989 325iX
1996 911 Turbo


Nick M3 is offline   Reply With Quote
Old 06-02-2021, 10:58 AM   #30
Nick M3
Relic
 
Nick M3's Avatar
 
Join Date: Oct 2003
Location: Bethesda, MD
Posts: 11,847
Fingers crossed. The whisper network pointed me at a guy who may have a crank...
__________________
2011 M3
2006 Sierra 2500HD 4WD LBZ/Allison
2004 X5 3.0i 6MT
1995 M3 S50B32
1990 325is
1989 M3 S54B32

Hers:
1989 325iX
1996 911 Turbo


Nick M3 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cool time lapse engine rebuild video Optimus Prime Technical Superiority 1 06-29-2012 12:40 PM
E30iT with S50b32 in NY--$11k JST Car Talk 3 08-26-2010 09:39 AM


All times are GMT -4. The time now is 02:46 AM.


Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Forums © 2003-2008, 'Mudgeon Enterprises - Site hosting by AYN & Associates, LLC