Cracked Piston- Sticky Injector?

**Bosephos** · 04-26-2012, 07:53 AM

Okay, so some of you know I'm building my motor. Basically I cracked a piston in my LBZ and decided I was going to build it while the motor is out. Here's my thing...I'm a bit worried about 1 of 2 things

The piston that cracked looked washed out, no soot on it like the other pistons...that has me feeling it could have cracked the head and I was getting coolant in there...

My other worry is that the injector for that cylinder may have stuck and caused that to happen. The crack goes straight across the piston...no holes or anything... I had to drive the truck for about 2 miles to get to home with it like this and I'm wondering if it could possibly be from all the fuel spraying on it during that time that washed the soot off... I'm just looking for thoughts... I'll have the heads pressure checked while at the machine shop...I'm just trying to think of other possibilities..

The truck did have some beatings on it of over 600rwhp for daily use... I'm hoping it was just the repetitive abuse on the crappy lbz pistons...

**guytonLBZ** · 04-26-2012, 08:02 AM

have the injectors checked. IIRC that was part of the reason Chris got his cracked piston

**Bosephos** · 04-26-2012, 08:11 AM

How do they typically test them? Just run pressure through it to see if it leaks?

**guytonLBZ** · 04-26-2012, 08:33 AM

some do that and some bench flow them. bench flow is typically the best. IMHO if you cracked a piston and its a possible that its due to the injector id replace all 8. specially if its going into a built motor.

**Bosephos** · 04-26-2012, 08:49 AM

Quote:

Originally Posted by guytonLBZ

some do that and some bench flow them. bench flow is typically the best. IMHO if you cracked a piston and its a possible that its due to the injector id replace all 8. specially if its going into a built motor.

Yeah...it's just a lot more money for another set though when my 60% overs will carry me to the hp mark I want...If I do end up buying more I'm going with 100% over

**guytonLBZ** · 04-26-2012, 09:03 AM

if anything jus by new stock injectors and swap the nozzles

**Bosephos** · 04-26-2012, 11:00 AM

Quote:

Originally Posted by guytonLBZ

if anything jus by new stock injectors and swap the nozzles

Special tools required for that?

Clarke · 04-26-2012, 11:10 AM

i cracked a piston becasue i had 3 bad injectors.

here is a pic.

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SickLB7Crenshaw · 04-26-2012, 11:12 AM

Quote:

Originally Posted by Bosephos

Special tools required for that?

no just need a 1/2 socket, a vise and a torque wrench. Becareful not to loose the lil puck (its tiny) when u pull the nozzle off the injector.

**WisconsinHick1** · 04-26-2012, 11:16 AM

Quote:

Originally Posted by guytonLBZ

have the injectors checked. IIRC that was part of the reason Chris got his cracked piston

Yeah the injector was jacked up on Chris's truck.

Like everyone has said test the injectors.

I have a set of LB7 pistons for sale that would go good in that motor.

04-26-2012, 07:53 AM	eBay Motors #1 (permalink)
Bosephos Duramax Lifetime Supporter Join Date: Jul 2010 Posts: 352	Cracked Piston- Sticky Injector? Okay, so some of you know I'm building my motor. Basically I cracked a piston in my LBZ and decided I was going to build it while the motor is out. Here's my thing...I'm a bit worried about 1 of 2 things The piston that cracked looked washed out, no soot on it like the other pistons...that has me feeling it could have cracked the head and I was getting coolant in there... My other worry is that the injector for that cylinder may have stuck and caused that to happen. The crack goes straight across the piston...no holes or anything... I had to drive the truck for about 2 miles to get to home with it like this and I'm wondering if it could possibly be from all the fuel spraying on it during that time that washed the soot off... I'm just looking for thoughts... I'll have the heads pressure checked while at the machine shop...I'm just trying to think of other possibilities.. The truck did have some beatings on it of over 600rwhp for daily use... I'm hoping it was just the repetitive abuse on the crappy lbz pistons... __________________ 2003 LB7, Built trans, Studded, Airdog 165, EFI Live DSP5, DIamond Eye 4" straight pipe

04-26-2012, 08:02 AM	eBay Motors #2 (permalink)
guytonLBZ like a Ninja Join Date: Jan 2009 Location: Coeur d'Alene, Idaho Posts: 5,047	have the injectors checked. IIRC that was part of the reason Chris got his cracked piston __________________ Holton-22 USMC SOLD "06 chevy 2500HD LBZ 6spd,black and blacked out, CCSB 4X4 Custom Twins, EFI by IdahoROB, built trans W/1058 by ME, 40% nozzles, PPE manifolds & Up-pipes, BD Intercooler, lowered on 20" Fuels, 6000K HIDs, Best PASS to date 12.01 @111MPH BIG Thanks to: IdahoRob, Mike L., Suncoast, BD Diesel, PPE, Fuel, S&B, Industrial Injection Alligator Diesel Performance - 208-777-1977 Alligator Performance

04-26-2012, 08:11 AM	eBay Motors #3 (permalink)
Bosephos Duramax Lifetime Supporter Join Date: Jul 2010 Posts: 352	How do they typically test them? Just run pressure through it to see if it leaks? __________________ 2003 LB7, Built trans, Studded, Airdog 165, EFI Live DSP5, DIamond Eye 4" straight pipe

04-26-2012, 08:33 AM	eBay Motors #4 (permalink)
guytonLBZ like a Ninja Join Date: Jan 2009 Location: Coeur d'Alene, Idaho Posts: 5,047	some do that and some bench flow them. bench flow is typically the best. IMHO if you cracked a piston and its a possible that its due to the injector id replace all 8. specially if its going into a built motor. __________________ Holton-22 USMC SOLD "06 chevy 2500HD LBZ 6spd,black and blacked out, CCSB 4X4 Custom Twins, EFI by IdahoROB, built trans W/1058 by ME, 40% nozzles, PPE manifolds & Up-pipes, BD Intercooler, lowered on 20" Fuels, 6000K HIDs, Best PASS to date 12.01 @111MPH BIG Thanks to: IdahoRob, Mike L., Suncoast, BD Diesel, PPE, Fuel, S&B, Industrial Injection Alligator Diesel Performance - 208-777-1977 Alligator Performance

04-26-2012, 09:03 AM	eBay Motors #6 (permalink)
guytonLBZ like a Ninja Join Date: Jan 2009 Location: Coeur d'Alene, Idaho Posts: 5,047	if anything jus by new stock injectors and swap the nozzles __________________ Holton-22 USMC SOLD "06 chevy 2500HD LBZ 6spd,black and blacked out, CCSB 4X4 Custom Twins, EFI by IdahoROB, built trans W/1058 by ME, 40% nozzles, PPE manifolds & Up-pipes, BD Intercooler, lowered on 20" Fuels, 6000K HIDs, Best PASS to date 12.01 @111MPH BIG Thanks to: IdahoRob, Mike L., Suncoast, BD Diesel, PPE, Fuel, S&B, Industrial Injection Alligator Diesel Performance - 208-777-1977 Alligator Performance

04-26-2012, 11:10 AM	eBay Motors #8 (permalink)
Clarke Senior Member Join Date: May 2010 Location: Gardiner, Montana Posts: 906	i cracked a piston becasue i had 3 bad injectors. here is a pic. Welcome to Facebook - Log In, Sign Up or Learn More __________________ 2009 CC/SB/ LMM EFI live, Fass, EGR blocked, braced, and a few more odds and ends "Explicit Content" 2006 CC/SB/ LBZ- Sled pulling truck. shooting for 700+ hp t

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