Chevy/GMC Duramax 06-07 LBZ Discussion of Chevy and GMC Trucks with LBZ Duramax Turbo Diesel Engines

LBZ teardown w/a few pics

Thread Tools
 
Search this Thread
 
Old Apr 11, 2009 | 02:22 PM
  #1  
jpowel29's Avatar
Thread Starter
|
Diesel Enthusiast
Joined: Oct 2008
Posts: 156
Likes: 4
Default LBZ teardown w/a few pics

I finally got around to dis-assembling my stock long block. Motor has 12k miles of street driving, road trips, dyno runs, and drag racing with the mods shown in my sig. Back in January it dyno'ed 741hp/1188ft-lbs on a load cell DynoJet with around 2500us PW and under 22 degrees of timing. Injector balance rates were good when we pulled it, it did not smoke, rattle, or miss.

Hearing/reading all of the stories about holes in pistons and bent rods, I was concerned that I would find similar damage. The heads, head gaskets, valves, and valvetrain all look good.

With the heads off I could see witness marks from the valves making contact with the carbon build-up on the piston tops (My tune has me upshifting around 4400rpm and the motor had seen redline in the water box a few times). No bent valves or piston damage but it shows the need for QUALITY valve springs. Factory pushrods look good and roll across a small glass mirror w/no deflection.

The stock flexplate looks fine with no cracks, factory balancer and locating pins on the crank are fine. Oil pan was clean with no metal. Lifters are still like new. Two of the rod bearings need to be replaced as it looks like some trash/debris got passed through them at some point (all the rest look like new and the rod journals look good w/no scoring). Motor held above 30lbs of oil pressure hot at idle with 15-40Rotella (over 60lbs cold).

All the rods are straight (from initial visual inspection) pics attached. Pistons, rings, and wrist pins look excellent as well. EGTs got as high as 1600 degrees at the top end of the track with some pretty good black smoke.

Once I added oversize nozzles and twin pumps I shorted the oil change interval (I didn't do any oil analysis but watched it closely and changed it when I felt it was getting sooted - about every 2000-3000 miles). The tuning was kept low at low rpms per my request and I think this made the difference (I know I traded off torque and ET). The intake & exhaust upgrades helped manage EGTS with the heavier fuel tunes.
 
Attached Thumbnails LBZ teardown w/a few pics-rods-pistons-003.jpg   LBZ teardown w/a few pics-rods-pistons-005.jpg  
Reply
Old Apr 11, 2009 | 02:25 PM
  #2  
2500HeavyDuty's Avatar
Super Moderator
Joined: Oct 2007
Posts: 14,872
Likes: 764
From: Houston, Tx
Default

what rods and pistons are you building with, if you are building the motor?
 
Reply
Old Apr 11, 2009 | 03:13 PM
  #3  
jpowel29's Avatar
Thread Starter
|
Diesel Enthusiast
Joined: Oct 2008
Posts: 156
Likes: 4
Default

I have Crowers in my new motor.
 
Reply
Old Apr 11, 2009 | 03:54 PM
  #4  
2500HeavyDuty's Avatar
Super Moderator
Joined: Oct 2007
Posts: 14,872
Likes: 764
From: Houston, Tx
Default

cool buisness.

weird that theres no injector spray pattern on your pistons
 
Reply
Old Apr 11, 2009 | 04:13 PM
  #5  
jpowel29's Avatar
Thread Starter
|
Diesel Enthusiast
Joined: Oct 2008
Posts: 156
Likes: 4
Default

Nope. With the oversize nozzles and the lowered timing I think most of the spray was contained to the piston bowl (just me guessing but you tend to see it with the big pw & high timing numbers)
 
Reply
Old Apr 11, 2009 | 04:20 PM
  #6  
2500HeavyDuty's Avatar
Super Moderator
Joined: Oct 2007
Posts: 14,872
Likes: 764
From: Houston, Tx
Default

Originally Posted by jpowel29
Nope. With the oversize nozzles and the lowered timing I think most of the spray was contained to the piston bowl (just me guessing but you tend to see it with the big pw & high timing numbers)

interesting

come to think of it the pistons ive seen with spray patterns on them do comr from motors that ran high timing
 
Reply
Old Apr 11, 2009 | 08:35 PM
  #7  
RodZZilla's Avatar
WhiskeyRiver took my mind
Joined: Jun 2007
Posts: 1,131
Likes: 52
From: Grinnell, IA
Default

How is the new one running, John?
 
Reply
Old Apr 11, 2009 | 09:12 PM
  #8  
jpowel29's Avatar
Thread Starter
|
Diesel Enthusiast
Joined: Oct 2008
Posts: 156
Likes: 4
Default

Rod - It is going strong. I am still make some small changes but it will hit the track next Friday (I hope). I plan on running it at TS in May so I need to get some laps on it.

What's new on your's?
 
Reply
Old Apr 11, 2009 | 11:00 PM
  #9  
RodZZilla's Avatar
WhiskeyRiver took my mind
Joined: Jun 2007
Posts: 1,131
Likes: 52
From: Grinnell, IA
Default

Still waiting for the turbo to get done. And then figure out how to make enogh $$ to go to St Lucas for a tranny.
 
Reply
Old Apr 11, 2009 | 11:03 PM
  #10  
2500HeavyDuty's Avatar
Super Moderator
Joined: Oct 2007
Posts: 14,872
Likes: 764
From: Houston, Tx
Default

Originally Posted by RodZZilla
Still waiting for the turbo to get done. And then figure out how to make enogh $$ to go to St Lucas for a tranny.
whats going on wiht yours?
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
duramaxtuner
06-07 LBZ Performance
1
Dec 10, 2014 02:00 PM




All times are GMT -5. The time now is 03:34 PM.