LB7: SAC-style Injector Life

Mpsoldier

That just happened!
Mar 10, 2010
646
0
16
In my House
Haven't heard of that many body failures myself except for guys running 200mpa+ for rail pressure. The SAC design should help cut down on hazing, nozzle dribble from not fully seating pintle's, and most any other nozzle problems. Unfortunately it doesn't do anything for ball seat erosion, but that hasn't been much of a problem since the revised ball seats came out in 09. Only time will tell, and they just haven't been out that long for the LB7. I foresee future problems similiar to those of the LLY+ now that the SAC design should take care of any nozzle problems, so I would expect to see problems of high return rates if you have problems.

good to know appreciate the thread always enjoy learning.:thumb:
 

clrussell

pro-procrastinator
Sep 23, 2013
5,928
399
83
So bump to this thread.. Ordering injectors today or tomorrow..

Thinking 30% normals or 45% sac.. Only $400 difference..

Just do the 45s and be done with it?
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,667
5,813
113
Phoenix Az
So bump to this thread.. Ordering injectors today or tomorrow..

Thinking 30% normals or 45% sac.. Only $400 difference..

Just do the 45s and be done with it?

Yes....... and rods :rofl: (im not letting that go as you can tell :D)
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
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Boise, ID, USA
I'll do a update again in a couple weeks with data, but just going on how it seems subjectively, they seem to be holding up great. Unlike my SoCal heads...

Sent from my FlashScan V2
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
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Boise, ID, USA
SAC injector update

Day 111 (3 months, 19 days)
Hours on injectors: 86.7
Miles on injectors: 3,794
Fuel injected: 236.6 gal
Miles on motor: 14,590
Miles on truck: 310,826
Code:
           Drive  Park
BALRCYL1   -2.08  -1.40
BALRCYL2   +3.01  +2.19
BALRCYL3   -1.60  -0.82
BALRCYL4   -0.66  -0.56
BALRCYL5   +1.50  +1.19
BALRCYL6   -0.46  +0.04
BALRCYL7   +0.12  +0.00
BALRCYL8   -0.10  -0.21
MAINRATE 14.1mm3 8.4mm3
After some tweaks to the tuning, I now have my main rate at about 8mm3 at hot idle. Balance rates look fantastic still (except #2, more on that below), and no smoke or smell at idle. Injectors seem to be lasting great, but with only ~4k miles, that is to be expected, I suppose.

I did figure out why the balance rate for cylinder #2 is consistently high, though. I recently changed heads, and re-measured piston protursion. When my first set of [THREAD=63518]SoCal Stage 1 heads cracked and hydrolocked my engine[/THREAD], it appears to have shortened the #2 Carillo rod by about 0.006". So that explains that :mad:

As for mileage, it does appear that the SAC style injectors do a bit better. I would say a solid 1.0 to 1.2 MPG based on my records. Can't complain about that!
 
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S Phinney

Active member
Aug 15, 2008
4,008
18
28
Quncy, Fl
I have a set in a lb7 for approximately 2 years and 100k or so miles. Everything is still going strong.

Sent from my SM-G920V using Tapatalk
 

SickLL7Crenshaw

Billy The Kid
Mar 10, 2013
1,088
34
48
31
Mexico
I have a injector going out again on my lb7 and thinking when I order the next set I'll go ahead and get the SAC from LDS. I'll be calling in the morning Brent, had another truck show up today that needs injectors.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
I put a decent amount of miles on this summer going camping and the like, but didn't record all the detailed diags yet. And since my heater core is leaking and I bypassed it, I haven't been driving my truck much this fall. If I take it out again soon, I'll get detailed stats.

For now, you'll have to make do with a subjective update. Since my last update in July, the truck has kept running great, with no indications the injectors are wearing out at all. Mileage is still excellent as well. From what I've seen so far, I wouldn't hesitate to put a 45% set of SAC injectors in.

Sent from my FlashScan V2
 

SickLL7Crenshaw

Billy The Kid
Mar 10, 2013
1,088
34
48
31
Mexico
Sub'd
Who else is running the sac style injectors? Dave how many miles do you have on them now? My lb7 is starting to haze again and I'm tired of only getting 25-40k miles on a set of injectors because this truck puts on 25k miles a year. I've already had to put 3 injectors in since February as they were pretty much hung open. Guess I'll be calling Brent sooner then I expected for a set of 45% SAC injectors.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
Dave how many miles do you have on them now?
Probably only 1000 or so miles since last time. Since I still don't have a heater (new core is sitting in the garage, I'm just busy/lazy) I only drive it when towing or hauling something. From what I can tell, the SAC injectors are still working perfect. I'll post a formal update next spring with the hours/miles/balance rates/etc once I have the heater core in and put some real miles on it. Or maybe sooner if I have the time.
 

bigmackmiller

Active member
Nov 30, 2008
1,046
2
38
Kokomo, IN
Sub'd
Who else is running the sac style injectors? Dave how many miles do you have on them now? My lb7 is starting to haze again and I'm tired of only getting 25-40k miles on a set of injectors because this truck puts on 25k miles a year. I've already had to put 3 injectors in since February as they were pretty much hung open. Guess I'll be calling Brent sooner then I expected for a set of 45% SAC injectors.

Are these your 100 overs? My stock one's are hazing, i keep going back and forth on fixing it or going the lbz conversion route, but at least encouraging that there is some longevity on the sac's
 

SickLL7Crenshaw

Billy The Kid
Mar 10, 2013
1,088
34
48
31
Mexico
Are these your 100 overs? My stock one's are hazing, i keep going back and forth on fixing it or going the lbz conversion route, but at least encouraging that there is some longevity on the sac's

Mine are just stock. Ya idk I have another spare lb7 engine here that needs HGs done and I'm thinking about studding it, going with LDS 45 sac styles, new HP lines and russels 63.5 ihi then when this motor goes just dropping that spare engine (150k miles compared to my 315k mile motor) in with the goodies.
 

bigmackmiller

Active member
Nov 30, 2008
1,046
2
38
Kokomo, IN
Mine are just stock. Ya idk I have another spare lb7 engine here that needs HGs done and I'm thinking about studding it, going with LDS 45 sac styles, new HP lines and russels 63.5 ihi then when this motor goes just dropping that spare engine (150k miles compared to my 315k mile motor) in with the goodies.

I gotcha think I got it mixed up with your LLY, yeah im kinda thinking something similar if I stick with the lb7, but will need trans built... gonna get expensive