Carnage - need input
You lost fuel pressure. It went down when it should have gone up.
I see CL comp trying to keep up, but it didn't.
Depending on your fuel rail routing, maybe 7 and 8 simply melted. And or detonated like crazy.
It just takes an instant.
I'm puzzled I guess why no knock sensors? Doesn't Holley support them?
Ron
I see CL comp trying to keep up, but it didn't.
Depending on your fuel rail routing, maybe 7 and 8 simply melted. And or detonated like crazy.
It just takes an instant.
I'm puzzled I guess why no knock sensors? Doesn't Holley support them?
Ron
You lost fuel pressure. It went down when it should have gone up.
I see CL comp trying to keep up, but it didn't.
Depending on your fuel rail routing, maybe 7 and 8 simply melted. And or detonated like crazy.
It just takes an instant.
I'm puzzled I guess why no knock sensors? Doesn't Holley support them?
Ron
I see CL comp trying to keep up, but it didn't.
Depending on your fuel rail routing, maybe 7 and 8 simply melted. And or detonated like crazy.
It just takes an instant.
I'm puzzled I guess why no knock sensors? Doesn't Holley support them?
Ron
I really like the knock sensors in my Buicks. Can't speak for Vince, but I tried to use them with the LS. With the solid motor mounts (due to frame mounted turbo). There was way too much noise. Seems like most use motor plates or solid mounts.
Thread Starter
Joined: Nov 2009
Posts: 1,621
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From: THORNTON, PA (NEAR PHILLY)
You lost fuel pressure. It went down when it should have gone up.
I see CL comp trying to keep up, but it didn't.
Depending on your fuel rail routing, maybe 7 and 8 simply melted. And or detonated like crazy.
It just takes an instant.
I'm puzzled I guess why no knock sensors? Doesn't Holley support them?
Ron
I see CL comp trying to keep up, but it didn't.
Depending on your fuel rail routing, maybe 7 and 8 simply melted. And or detonated like crazy.
It just takes an instant.
I'm puzzled I guess why no knock sensors? Doesn't Holley support them?
Ron
I just cant believe 7/8 melted from deto and the other dont show any indication of deto. Could be wrong.
Not running knock sensors cause I felt my tune was safe enough that I wasnt close to the edge. When the motor let go it was 15.5psi, 16* and the 100/93 octane mix...I dont think that's enough to take a motor out.
Only other thing that I can think of is that this motor bent the all the drivers side rods during a ignition coil grounding issue. I replaced all the rods and it ran good up until now. Wondering if there was some sort of damage that was not evident to the naked eye??
Again, she never really ran up top like I thought she should have....
Willing to bet your Wideband wasn't fast enough to catch the lean out. The dyno that I go to has the $1000 wideband that can catch quick misfires etc, the AEM WB I have never sees them because its not fast enough. Backpressure may be why you were low on power to begin with and certainly could have contributed to the destruction.
Closed loop did keep up...it just didnt need to add anything as the AFR was inline at 11.5:1. After it blew-up it started adding fuel...probably b/c the o2 sensor started to detect air (misfire).
I just cant believe 7/8 melted from deto and the other dont show any indication of deto. Could be wrong.
Not running knock sensors cause I felt my tune was safe enough that I wasnt close to the edge. When the motor let go it was 15.5psi, 16* and the 100/93 octane mix...I dont think that's enough to take a motor out.
Only other thing that I can think of is that this motor bent the all the drivers side rods during a ignition coil grounding issue. I replaced all the rods and it ran good up until now. Wondering if there was some sort of damage that was not evident to the naked eye??
Again, she never really ran up top like I thought she should have....
I just cant believe 7/8 melted from deto and the other dont show any indication of deto. Could be wrong.
Not running knock sensors cause I felt my tune was safe enough that I wasnt close to the edge. When the motor let go it was 15.5psi, 16* and the 100/93 octane mix...I dont think that's enough to take a motor out.
Only other thing that I can think of is that this motor bent the all the drivers side rods during a ignition coil grounding issue. I replaced all the rods and it ran good up until now. Wondering if there was some sort of damage that was not evident to the naked eye??
Again, she never really ran up top like I thought she should have....
It only takes a nano second for the AFR to go wrong and the motor to grenade.
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From: Norn Iron
So are you saying the pistons destructed, but the rods remained correctly bolted to the crank ?
and it's the rods that have done the damage ?
Or have those rod bolts came out on their own whilst running ?
I'd find it hard to believe any amount of detonation would lead to such damage though.
And regardless as said before, it is idiotic not to use knock sensors, whether for information only or when correctly set up for feedback and timing adjustments based on any noise.
If the sensors had been fitted, even if they were doing nothing the logs might have yielded some more information as to what was going on prior to the damage.
Solid mounts shouldnt pose an issue to a good knock setup anyway
and it's the rods that have done the damage ?
Or have those rod bolts came out on their own whilst running ?
I'd find it hard to believe any amount of detonation would lead to such damage though.
And regardless as said before, it is idiotic not to use knock sensors, whether for information only or when correctly set up for feedback and timing adjustments based on any noise.
If the sensors had been fitted, even if they were doing nothing the logs might have yielded some more information as to what was going on prior to the damage.
Solid mounts shouldnt pose an issue to a good knock setup anyway
So are you saying the pistons destructed, but the rods remained correctly bolted to the crank ?
and it's the rods that have done the damage ?
Or have those rod bolts came out on their own whilst running ?
I'd find it hard to believe any amount of detonation would lead to such damage though.
And regardless as said before, it is idiotic not to use knock sensors, whether for information only or when correctly set up for feedback and timing adjustments based on any noise.
If the sensors had been fitted, even if they were doing nothing the logs might have yielded some more information as to what was going on prior to the damage.
Solid mounts shouldnt pose an issue to a good knock setup anyway
and it's the rods that have done the damage ?
Or have those rod bolts came out on their own whilst running ?
I'd find it hard to believe any amount of detonation would lead to such damage though.
And regardless as said before, it is idiotic not to use knock sensors, whether for information only or when correctly set up for feedback and timing adjustments based on any noise.
If the sensors had been fitted, even if they were doing nothing the logs might have yielded some more information as to what was going on prior to the damage.
Solid mounts shouldnt pose an issue to a good knock setup anyway
Rods would eject if the mixture lit off half way up the compression stroke. They would fold like a lawn chair.
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From: Norn Iron
All good and well, pre-ignition would never occur that low in the bore, and the post doesnt seem to suggest the rods failed ?
There are no photos or mention of the rods really, only mention of catastrophic piston damage, but no pics of that either.
Obviosuly one cylinder did let go first, but the other damage may be due to the first cylinder failing and being in such close proximity it's rod neighbour suffered heavy damage too.
There are no photos or mention of the rods really, only mention of catastrophic piston damage, but no pics of that either.
Obviosuly one cylinder did let go first, but the other damage may be due to the first cylinder failing and being in such close proximity it's rod neighbour suffered heavy damage too.
Thread Starter
Joined: Nov 2009
Posts: 1,621
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From: THORNTON, PA (NEAR PHILLY)
So are you saying the pistons destructed, but the rods remained correctly bolted to the crank ?
and it's the rods that have done the damage ?
Or have those rod bolts came out on their own whilst running ?
I'd find it hard to believe any amount of detonation would lead to such damage though.
and it's the rods that have done the damage ?
Or have those rod bolts came out on their own whilst running ?
I'd find it hard to believe any amount of detonation would lead to such damage though.
All good and well, pre-ignition would never occur that low in the bore, and the post doesnt seem to suggest the rods failed ?
There are no photos or mention of the rods really, only mention of catastrophic piston damage, but no pics of that either.
Obviosuly one cylinder did let go first, but the other damage may be due to the first cylinder failing and being in such close proximity it's rod neighbour suffered heavy damage too.
There are no photos or mention of the rods really, only mention of catastrophic piston damage, but no pics of that either.
Obviosuly one cylinder did let go first, but the other damage may be due to the first cylinder failing and being in such close proximity it's rod neighbour suffered heavy damage too.
I took all the rods off today, all the bearings were perfect and the other "good" 6 rods were straight. The pistons looked good too, and all the pins were nice and free. I took the crank out...it spun freely and all the bearings looked excellent also.
There was obviously a major mechanical failure, and I think it has to do with a piston somehow. Thinking the piston somehow broke and the resultant carnage. Maybe deto, maybe not. Again, the rest of the pistons look excellent. Possibly a pin seized and it was all downhill from there. I think the fact that the big ends of the rod were still bolted to the crank and spun freely tell me it wasn't the rod. If the rods bent, I think some of the other rods would of bent also.
Back to when I bent all the drivers side rods. Wondering if maybe there was a crack or something in one of the pistons I didn't see. BUT, I also believe I was down on power, which would rule out a cracked piston (at least until the end). Its almost like something was dragging and it finally gave way. I dunno.
I have a buddy who used solid mounts in his Firebird. He said it registered KR at idle. So his tuner either disconnected them or turned them off.
Two 5.3's later, he now has a forged 6.0. Still no knock sensors.
I simply used the orig interlocking mounts that were on my rat motor. My knock sensors are slightly de-sensitized, but catch the occasional knock that happens only during my burnouts. I've never seen any other knock but I'm on E85.
Hook them up in your new 5.3 Vince. They can provide valuable data.
I don't suppose you put the cutout in before she blew did you?
Got flex joints in there at all? Folks have seen failures with those that have caused high back pressure and blown engines.
Ron
Two 5.3's later, he now has a forged 6.0. Still no knock sensors.
I simply used the orig interlocking mounts that were on my rat motor. My knock sensors are slightly de-sensitized, but catch the occasional knock that happens only during my burnouts. I've never seen any other knock but I'm on E85.
Hook them up in your new 5.3 Vince. They can provide valuable data.
I don't suppose you put the cutout in before she blew did you?
Got flex joints in there at all? Folks have seen failures with those that have caused high back pressure and blown engines.
Ron
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
I just borrowed a bore scope to look at the flex joint - their fine. I'm using the Vibrant turbo-flex jobs which are not suppose to blow out. Never got a chance to run the cut-out either.
Possible that the crank slightly bent when I bent the rods? I would think the bearings would of shown something.
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
Bringing this back up as I wanted to get some opinions here...
Can't help but wonder what happened here, but in the end **** does happen when your pushing things that werent designed to be pushed. But, I determined that I was over-speeding the alternator which would make it stop generating voltage altogether, and it would reactive once rpms dipped below ~4500. Once engine rpms reached ~6080 in 1st gear the alternator would quit, resulting in making what was basically an entire 1/4 pass on battery voltage alone. When the engine let go I was down to about 12.4v. Could low voltage make the coils act funny in terms of misfires etc and cause an engine to dismantle itself? I did bend all the rods on the drivers bank only once from a loose coil ground, so I know the importance of coils getting proper grounding, just not sure about voltage.
I went to a larger alternator pulley and now voltage is just fine at WOT.
Can't help but wonder what happened here, but in the end **** does happen when your pushing things that werent designed to be pushed. But, I determined that I was over-speeding the alternator which would make it stop generating voltage altogether, and it would reactive once rpms dipped below ~4500. Once engine rpms reached ~6080 in 1st gear the alternator would quit, resulting in making what was basically an entire 1/4 pass on battery voltage alone. When the engine let go I was down to about 12.4v. Could low voltage make the coils act funny in terms of misfires etc and cause an engine to dismantle itself? I did bend all the rods on the drivers bank only once from a loose coil ground, so I know the importance of coils getting proper grounding, just not sure about voltage.
I went to a larger alternator pulley and now voltage is just fine at WOT.
TECH Resident
Joined: Sep 2013
Posts: 993
Likes: 119
From: Mechanicsburg, PA
Well to help on one point. If you never saw any lean O2 data right before it let go, it should not have been misfiring. My wideband picks up misfire very quickly as a lean spike. I highly doubt that a voltage of 12.4 volts could affect any of the systems mentioned. Most EMS' operate down to 9-10 volts as well. I know how you feel though wanting to know the cause of the carnage. It's a curse many of us deal with, hahaha!
