nightmare2012

What could've possibly caused this catastrophic failure a little bit on the setup is a ls3 with a 228/238 .625/.590 LSA 111 ported heads 500 miles on the setup. When we tore it apart besides the holes on the each side of the block we found a connecting rod completely cut in half a full piston missing only thing left floating around in the oil pan was the wrist pin the timing chain was also at the bottom of the pan any insight will be helpful

67Lark

If the chain broke at a high RPM it could have definitely broken the rod and exploded the piston.


it's amazing what an engine will do to itself at higher RPM

140K_GXP

Can you give more info? What rpm did this happen at? What kind of chain and what kind of tensioner?

Wild guess but I am thinking if it was the LS3 tensioner, it failed causing the timing chain to break, causing that piston to slam into the intake valve. Must have been at high rpm to cause that amount of carnage.

KCS

iTrader: (20)

What do the rest of the pistons look like? What does the big end of the broken rod look like and does it sprin freely on the rod journal?

nightmare2012

Yeah it was in the middle of a pull when it let go I was just trying to eliminate possible tune issues

67Lark

But as 140k said, it could have been a broken rod that snapped the chain, it could go either way. But being at a high RPM will cause catastrophic damage with ANY failure

Pyroproblem

How much torque and at what RPM are your guys' engines letting go?
TBH, it kinda seems like the rods just can't handle it. These are stock oem rods right?
Do any of the other rods have any signs of bend to them?

Fullblast

iTrader: (17)

**** hapens man. Same thing happened to me, but with 9,000 miles on a rebuilt ls1. Shattered the piston, windowed the motor, cracked oil pan,broke the sleeve and top of the block, messed up 2 valves and my bowl, destroyed my cam and a few lifters too....at least my timing chain stayed in place lol.

The shop that rebuilt and installed my engine....tuned my car with no 02 sensors hooked up.

So the New shop thats building my new engine told me that had been causing it to detonate like crazy and caused heat soak to burn up a rod bearing...which gave the rod some play....and one night i ran it to 6k and...kaboom. So I'm taking the shop that built it to court and sueing for damages.

DietCoke

iTrader: (18)

If the rod breaks and piston hits a valve at full rpm, it will shatter the chain. NOT the other way around. If the chain snaps the valves just shut (off the cam). If you are only down one hole, then the rod let go first. IF you're done many holes, it was probably the chain.

DietCoke

iTrader: (18)

Also, the rods in your picture aren't LS3 rods.