Please see pics of my turbo 5.3 cylinders and give me your opinion
08-22-2013, 10:51 PM
#1
TECH Apprentice
Thread Starter
iTrader: (20)
Join Date: Jul 2009
Location: Liberal land
Posts: 390
Likes: 0
Received 0 Likes
on
0 Posts
Please see pics of my turbo 5.3 cylinders and give me your opinion Basically to make a long story short, I have had the new 2 bar SD tune on this setup for about 1200 miles now. Been running excellent until the other day when the vacuum line popped off the wastage and it over boosted. A compression test revealed cylinder 7 was 60 PSI while the rest were 140-150 PSI. Pulled the head and saw this...
It appears that the other cylinders have a black carbon coating but cylinder 7 looks clean? Would this be caused by it detonating when it over boosted, or is there another issue in your opinions??
Setup is just a basic 317 headed 5.3, LS6 cam and intake, T76 at 11 PSI on 93 pump gas. I have been pounding the hell out of it for the last 1200 miles and it has run flawless until the mishap. I just basically want to know if I should look for possibly another problem like a non firing injector, or maybe no spark on that cylinder? Not really sure what would cause the piston to be cleaner than the others in all honesty.
It appears that the other cylinders have a black carbon coating but cylinder 7 looks clean? Would this be caused by it detonating when it over boosted, or is there another issue in your opinions??
Setup is just a basic 317 headed 5.3, LS6 cam and intake, T76 at 11 PSI on 93 pump gas. I have been pounding the hell out of it for the last 1200 miles and it has run flawless until the mishap. I just basically want to know if I should look for possibly another problem like a non firing injector, or maybe no spark on that cylinder? Not really sure what would cause the piston to be cleaner than the others in all honesty.
08-22-2013, 11:39 PM
#3
TECH Apprentice
Thread Starter
iTrader: (20)
Join Date: Jul 2009
Location: Liberal land
Posts: 390
Likes: 0
Received 0 Likes
on
0 Posts
Sorry, I totally forgot to mention that it did crack a ringland on #7 which was my original reason for ripping it apart. I have spare pistons so I planned on throwing one in and running it. What scared me was the fact that cylinder 7 looks so much cleaner than the others.......thats what I was really asking about. Any opinions on that aspect?
08-22-2013, 11:39 PM
#5
Launching!
iTrader: (4)
Join Date: May 2010
Location: asheboro, nc
Posts: 289
Likes: 0
Received 0 Likes
on
0 Posts
could be a few things
The injector not giving enough fuel like u said
Maybe the head picked up an let water in, steam cleaned the cylinder an some times it can crack the valves or a seat etc.
But I ain't seen that happen on a ls yet
The injector not giving enough fuel like u said
Maybe the head picked up an let water in, steam cleaned the cylinder an some times it can crack the valves or a seat etc.
But I ain't seen that happen on a ls yet
Trending Topics
08-22-2013, 11:46 PM
#8
TECH Apprentice
Thread Starter
iTrader: (20)
Join Date: Jul 2009
Location: Liberal land
Posts: 390
Likes: 0
Received 0 Likes
on
0 Posts
So basically I shouldn't get too caught up in thinking something else is up with an injector or something? I'm not new to cracked ringlands as you can see from my cylinder 3 and 5 pistons having the crosses on them while the rest do not, lmao. I keep spare pistons for that reason. Can usually have it fixed and back together now in 2-3 days. I'll really be in trouble if I run out of spare pistons though!
08-23-2013, 01:02 AM
#11
TECH Apprentice
Thread Starter
iTrader: (20)
Join Date: Jul 2009
Location: Liberal land
Posts: 390
Likes: 0
Received 0 Likes
on
0 Posts
Besides the replacement piston, it costs me roughly $100 to fix it each time. $40 for a head gasket, $50 for a new ring set, and $10 for an exhaust manifold gasket. Really can't complain at that price, and if it lasts another 1000 miles and then slings a rod, the enjoyment factor far outweighs the $100 bucks and time I spent to fix it.
I also tune it myself, so I really wanted the cheap engine while learning to tune. At the moment, the tune is almost perfect and the car has been running great. Now if my luck improved, I'd be all set!
Thanks as well for the laser heat gun idea. I have one at work that I use so it would be no problem to borrow it to check out the motor once it's back in action. Don't have any O2's on the car since my wideband is the sole sensor I use to tune it.
08-23-2013, 01:08 AM
#12
I honestly thought about building a forged bottom end, but it's just too fun playing with the junkyard stuff! It'll make 600 HP all day long and the only issues I've had with the pistons were caused by unfortunate mishaps. If not for those, the engine would take the abuse all day!
Besides the replacement piston, it costs me roughly $100 to fix it each time. $40 for a head gasket, $50 for a new ring set, and $10 for an exhaust manifold gasket. Really can't complain at that price, and if it lasts another 1000 miles and then slings a rod, the enjoyment factor far outweighs the $100 bucks and time I spent to fix it.
I also tune it myself, so I really wanted the cheap engine while learning to tune. At the moment, the tune is almost perfect and the car has been running great. Now if my luck improved, I'd be all set!
Thanks as well for the laser heat gun idea. I have one at work that I use so it would be no problem to borrow it to check out the motor once it's back in action. Don't have any O2's on the car since my wideband is the sole sensor I use to tune it.
Besides the replacement piston, it costs me roughly $100 to fix it each time. $40 for a head gasket, $50 for a new ring set, and $10 for an exhaust manifold gasket. Really can't complain at that price, and if it lasts another 1000 miles and then slings a rod, the enjoyment factor far outweighs the $100 bucks and time I spent to fix it.
I also tune it myself, so I really wanted the cheap engine while learning to tune. At the moment, the tune is almost perfect and the car has been running great. Now if my luck improved, I'd be all set!
Thanks as well for the laser heat gun idea. I have one at work that I use so it would be no problem to borrow it to check out the motor once it's back in action. Don't have any O2's on the car since my wideband is the sole sensor I use to tune it.
08-23-2013, 01:08 AM
#13
I honestly thought about building a forged bottom end, but it's just too fun playing with the junkyard stuff! It'll make 600 HP all day long and the only issues I've had with the pistons were caused by unfortunate mishaps. If not for those, the engine would take the abuse all day!
Besides the replacement piston, it costs me roughly $100 to fix it each time. $40 for a head gasket, $50 for a new ring set, and $10 for an exhaust manifold gasket. Really can't complain at that price, and if it lasts another 1000 miles and then slings a rod, the enjoyment factor far outweighs the $100 bucks and time I spent to fix it.
I also tune it myself, so I really wanted the cheap engine while learning to tune. At the moment, the tune is almost perfect and the car has been running great. Now if my luck improved, I'd be all set!
Thanks as well for the laser heat gun idea. I have one at work that I use so it would be no problem to borrow it to check out the motor once it's back in action. Don't have any O2's on the car since my wideband is the sole sensor I use to tune it.
Besides the replacement piston, it costs me roughly $100 to fix it each time. $40 for a head gasket, $50 for a new ring set, and $10 for an exhaust manifold gasket. Really can't complain at that price, and if it lasts another 1000 miles and then slings a rod, the enjoyment factor far outweighs the $100 bucks and time I spent to fix it.
I also tune it myself, so I really wanted the cheap engine while learning to tune. At the moment, the tune is almost perfect and the car has been running great. Now if my luck improved, I'd be all set!
Thanks as well for the laser heat gun idea. I have one at work that I use so it would be no problem to borrow it to check out the motor once it's back in action. Don't have any O2's on the car since my wideband is the sole sensor I use to tune it.
What head bolts are you using? Are you opening up the ring gap wider than stock when you replace the rigns? Do you stick a new rod and piston in? Or just have the new piston pressed on the old rods?EDIT I see you have ARP head studs.
08-23-2013, 01:15 AM
#14
TECH Apprentice
Thread Starter
iTrader: (20)
Join Date: Jul 2009
Location: Liberal land
Posts: 390
Likes: 0
Received 0 Likes
on
0 Posts
On page 4 of your build thread now. What head bolts are you using? Are you opening up the ring gap wider than stock when you replace the rigns? Do you stick a new rod and piston in? Or just have the new piston pressed on the old rods?
EDIT I see you have ARP head studs.
What head bolts are you using? Are you opening up the ring gap wider than stock when you replace the rigns? Do you stick a new rod and piston in? Or just have the new piston pressed on the old rods?EDIT I see you have ARP head studs.
