GT-ER

I typed the first sentence wrong. It was supposed to read "That's not all from detonation, at least not entirely" instead of "That's not detonation all, at least not entirely". I didn't realized until now that I typed it wrong and I can see how it changes to context completely.

To continue what I said above, I agree that it was probably caused by detonation...but the ENTIRE extent of the damage wasn't just detonation in one short burst that blew the engine to pieces. That piston saw extended amounts of detonation for a long period of time ( a long period of time could be a few hours instead of ONE large catastrophic failure ).

The top land on that piston is still intact ( melted, but in once piece ). The mid land between the ring grooves is obviously destroyed and those parts caused so much heat due to friction that it caused a hole on the side of the piston.

That piston may not even have seen detonation at all...as I said earlier...another piston that breaks due to detonation can cause pieces to go into other chambers and destroy perfectly good pistons. Although unlikely...it is possible and I have seen it before.

jcjmw

IF, if there was enough fuel, then that would have prevented the detonation?

GT-ER

It would definitely help. But detonation can occur for various reasons such as incorrect timing, cylinder head hot spots, piston hot spots and incorrect air/fuel ratio.

BBBSS

Haha, oh I know its been done many many many times in the LS community. I meant I don't think anyone's tried that power level on the 55K motors yet though.

I was building an Iron block 370 that was gonna run a D1SC for all it was worth with a small shot on top of it for my old 99 Camaro SS. Got 95% of the parts and while building somehow ended up deciding to part it all out, trade and sell some cars, and pick up my Harley. I picked up the old HP Tuners car that started his whole company in the process (see sig). It's held several LS and V6 records. Original V6 car. Battled with Juggernaut for cam only and Head/Cam record and went back and forth a few times between them. Redone to something a lil different now but I love the history of the car.

BBBSS

One dead piston can contaminate them all for sure. Had a friend that picked up a first year Trailblazer with the inline motor. I guess very early ones had issues with casting and the wall would crack and kill the piston which is what happened to my buddy. Bought the car at carmax and floored it getting in the highway after buying and she let go. Towed back, and they showed him what it looked like after pulling the head. Every cylinder and the intake had chunks of piston. Carmax stepped up and tossed him a new motor with no trouble.

sneakyneon

Was that an 03 engine by chance?

shardul

iTrader: (1)

no it was a 05

Exotic-metal55

My first motor (picture of ring land busted) , is an 03.

chawkins2001

Woah Brooke, some company seems to be breaking records by blowing one engine at a time.

lowprofile

What??? I'm still in for your explanation GT-ER. Here is your quote again;

"That looks like a heat related failure due to friction"

I have never seen, or even heard of, a piston failing due to friction in this manner.

Maybe a few scuffs from being too tight on the piston to wall clearance, but this piston is not showing any signs of that.

loungn14

if only he had some of brookes upgraded red top injectors....might have been a different story..

LOCO 05' E55

Love these threads

How many times didnt i run up to the 150mph Mark on stock injectors with the OE tune

My fastest quarter mile times were accomplished on stock injectors/Rail..AFR's consistently in the mid to low 11's..V-box'n at the track all the way up to 140s-145mph in 35f weather..

But then again i changed my oil and plugs before every track event

Exotic-metal55

I have to agree Lowprofile.


Here, this is the hole that melted , blown up piston came out of. This was instant, as the car came off the freeway, punched it and bam! Knocking, oil and smoke!

Good thing about these pictures, is it lets eveyone take a deep breath and do a little reality check. Then we all grow safe again !




More blood and guts. This is my first motor stage 1 with stock parts and 38K on it. This is the whole that number 3 exploded and ruined blower and all. Rod beat the hell out of the cylinder.

BRUTALLYHONEST

So what do all these damaged engine parts have in common? Is there one part that all these engines have shared? There might be a common cause to all these failures. Is the same person tuning all these? We run lambda sensors on all cylinders on our race cars to avoid catastrophic failures like these. There is no reason this should happen other than negligence.

LOCO 05' E55

Problem with most here is that 8 out of 10 guys "DO NOT" Wideband their cars and just go by what power they made at the the dyno and what that sniffer (AFR reader) tells them in that particular dyno day..Every tuner IMO should recommend these data logging devices and include a little educating about all these numbers before anything.

kustom2k1

Why didn't the knock sensor prevent this?

chawkins2001

Innovator widebands are your friends and are relatively cheap.

chawkins2001

That reminds me, Shardul, could you pm me some pics of your wideband setup please brotha.

shardul

iTrader: (1)

my main goal was to have everything more or less in the line of sight. did not want to mess with a pillar gauge pod since there is an air bag in there. all gauges have a analog 5v output for datalogging

GT-ER

Ummm...I'll quote myself then since you obviously missed it.

I guess maybe you haven't seen too many failed pistons....I had a box full of them when my bro had his shop. He used to race cars ( not drag race but auto x ) and he had a quite a few failures in his vehicle along with other vehicles from his crew. We would have to assess the damage from the pistons in order to figure out where what failed first to learn from it. It's not easy trying to squeeze every little drop of power from an engine that mostly had to remain stock.

Anyways, it was just an observation...if you don't like it then you are welcome to post your own.

GT-ER

The engine may have blown up in a spectacular fashion...but that piston probably saw detonation for some time before the engine blew up...you just didn't know about it.

kustom2k1

Why did the knock sensor not work to stop the damage? Detonation is audible and the KS should have picked it up.

GT-ER

Knock sensors can only mitigate detonation, but they cannot ultimately stop it. They have limitations.

Gadget

What is the material the pistons are made from, are they forged?

What about the connecting rods?

The cylinders in the block, do they have cast in ductile iron liners or are they the chemically etched glass liners like the older 3.8L V8 engines??

G

lowprofile

Ok, so let me get this straight, you use to examine pistons from racing engines, and you came up with "friction heat related piston failure" after seeing this piston with the hole in the side of it?
Well that would definitely explain why you had a box full of them to examine.

Ok, carry on. Thanks for playing along with me.