LLY: cracking injector bodies

juddski88

Freedom Diesel
Jul 1, 2008
4,657
120
63
Chesterfield, Mass.
I cracked #7 injector body pretty bad Saturday night. Also popped the hold down out 1/8"
. I dint have a relief valve in my high pressure system anymore...should I think about incorporating one now? Ive heard of guys like Tim Jackson running some custom ones for a similar reason. I am commanding 26k on these lly bodies, should I back it down a bit? Also, anyone have a simple source for hold down studs and conical washers/nuts? I cant even believe how different this truck feels down here at sea level, with new tuning and Davids heads and cam. We've got some more tuning left to do but with the combined efforts of James Dow, Ben, Dylan, Trent and Kyle, we are closer than we've ever been to having it dialed in. everyone asked why I was so happy after the pull even with the damage and the resulting fuel fire, haha...it's taken a long time to get it to this point
 

Sledheadxp800r

That was only my tow tune
Dec 13, 2010
1,151
0
0
39
CT
Tim your truck was a beast Saturday. :thumb: Makes me want to get going again on my build.
 
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03badmaxxx

Ghost Element
Mar 1, 2012
825
0
0
Mesa,AZ
www.facebook.com
last i knew guys "billet" hold downs were off the market because a flaw found in the material? (was what i heard) and he was in the process of redesigning them with a better material.. Weather this is true or not i haven't heard. He does have the ARP stud kit though as he is where i got mine from..
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
It really is strange that they cracked? Ive been running my 40% at 26k+ and they have almost 200k miles on them, and Schulte's 125% over injectors, we run those at 26-27k, no problems.

Maybe just a fluke that yours cracked Tim??? :confused:

The only thing I can think of is maybe the LB7 FICM and/or the "unorthodox" (to say the least) tuning you have to run to make your setup run properly puts more stress on the injectors??????
 

juddski88

Freedom Diesel
Jul 1, 2008
4,657
120
63
Chesterfield, Mass.
I'll have my local machinists make me up some hardened hold downs if i need them...the hold down is not cracked or bent...just stretched the bolts.....making some cylinder pressure now at sea level!
 

juddski88

Freedom Diesel
Jul 1, 2008
4,657
120
63
Chesterfield, Mass.
It really is strange that they cracked? Ive been running my 40% at 26k+ and they have almost 200k miles on them, and Schulte's 125% over injectors, we run those at 26-27k, no problems.

Maybe just a fluke that yours cracked Tim??? :confused:


Dustin had issues too though, and Tim Jackson has had longevity issues due to pressure also. gotta remember too, my cp3's flow 3 times the stock fuel flow...
 

03badmaxxx

Ghost Element
Mar 1, 2012
825
0
0
Mesa,AZ
www.facebook.com
I'll have my local machinists make me up some hardened hold downs if i need them...the hold down is not cracked or bent...just stretched the bolts.....making some cylinder pressure now at sea level!

the difference my truck ran from when i lived in colorado to now in Fort walton beach is night and day for sure
 

quadracer37

New member
Mar 31, 2009
547
0
0
northern, IL
some pullers around us where having trouble cracking lbz bodies last year. all it takes is one pressure spike. exergy told me you should always have a relief valve. guy has stud kits for the hold downs, far as i know his hold downs are still avaliable to.
 

JRODS*LB7

New member
Feb 1, 2012
642
0
0
44
SE Massachusetts
It really is strange that they cracked? Ive been running my 40% at 26k+ and they have almost 200k miles on them, and Schulte's 125% over injectors, we run those at 26-27k, no problems.

Maybe just a fluke that yours cracked Tim??? :confused:

The only thing I can think of is maybe the LB7 FICM and/or the "unorthodox" (to say the least) tuning you have to run to make your setup run properly puts more stress on the injectors??????
He needs to stop spraying a whole can of ether to start his truck up...lol...j/k:D
 

juddski88

Freedom Diesel
Jul 1, 2008
4,657
120
63
Chesterfield, Mass.
that's what everyone tells me, but without my glows ive never been able to start this truck with either motor, and this one has higher compression! cranking injection quantity is still stock, maybe that needs a tweek? i dont know. it can be 100 degrees out and if the motor is cold it wont start. needs to be 110 degrees ECT before the truck runs clean
 

05_LLY

Out-A-Time
Aug 7, 2006
1,756
1
36
43
Norvelt, PA
I run the pumps wide open on our llys injectors, sensor stays pinned at 26, xxx during pulls, two seasons now same injector bodies. Also run a 3 shim relief valve though.
 

juddski88

Freedom Diesel
Jul 1, 2008
4,657
120
63
Chesterfield, Mass.
I run the pumps wide open on our llys injectors, sensor stays pinned at 26, xxx during pulls, two seasons now same injector bodies. Also run a 3 shim relief valve though.

these were Tony's before mine. Not sure how long they have been in service. I know they were less than stellar before Exergy got a hold of them in 2009. Out of balance. I know i am commanding more of them now than he did though
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
3,890
44
48
44
ZEPHYRHILLS, FL
Maybe your rail pressure sensor is sticking and it is going higher than the 26K without it knowing it. Also the rail pressure sensor is scaled to read up to 200MPA? Stock only goes to 180 and it will spike above 26K if you command more than 180 without rescaling the rail ressure sensor. Not trying to offend, just know that sometimes the simplest detail can be overlooked and cause a serious issue.