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I need some opinions on what happened to my engine today. This is on my new LS3 build, ls3 block, 4.07 mahle pistons, lunatic rods and stock 823 heads, the engine only has about 20 miles on it. I was backing my car out of the garage and it made a strange noise, I thought the exhaust came loose and then it died.
I tried to start it again but the starter just clicked, at this point I was thinking that the battery was dead. So as I walked back to the car I noticed coolant leaking out of the x pipe. So now I know that the engine is hydro locked and I began pulling the spark plugs. They all looked good except the #1 cylinder was full of coolant.
I also pulled the valve cover and the cylinder 1 intake rocker is also broken. I'm pulling the engine to have my builder go back through it, he thinks it's from a cracked head but what kind of damage can I expect?
You have a keeper missing on that intake valve. Is the valve still up in the head, or has it dropped into the cylinder?
It’s prolly in the cylinder id guess, and it’s not gonna be pretty. Sorry to see this mess man...
You have a keeper missing on that intake valve. Is the valve still up in the head, or has it dropped into the cylinder?
It’s prolly in the cylinder id guess, and it’s not gonna be pretty. Sorry to see this mess man...
Yeah, the valve dropped into the cylinder. The keeper that was missing was laying in the head.
I can see the other keeper in the head left of the spring and oh yeah it dropped the valve. Damn that sucks! It's certainly not going to be a pretty picture once that head is removed.
Damn sorry man, this really sucks. Trying to wrap my head around what happened first... Were there any signs of a cracked head before this happened (coolant loss, misfire)? Do you know what spring kit is on there and has anyone verified the keepers and retainers match angles? Make sure you save the loose keeper so it can be checked. By the look of the #1 spark plug I wouldn’t be surprised if the valve head punched right through the head casting.
Yup same here. I highly suspect either the keepers weren’t seated or maybe that 1 keeper was not compatible with the retainer angle. Hopefully the builder will cover the loss if that’s the case.
My guess and it's obviously a guess, Valve head broke off at base of stem, punched hole in the head itself and kept the valve stem from being pushed down by the rocker arm and that broke the rocker arm and the broken rocker arm pushed the retainer down allowing the keeper to fall out.
My guess and it's obviously a guess, Valve head broke off at base of stem, punched hole in the head itself and kept the valve stem from being pushed down by the rocker arm and that broke the rocker arm and the broken rocker arm pushed the retainer down allowing the keeper to fall out.
What valves were used stock?
Very plausible. Bottom line I think the valve broke or dropped somehow. I do not think Cracked head was the primary issue.
My guess and it's obviously a guess, Valve head broke off at base of stem, punched hole in the head itself and kept the valve stem from being pushed down by the rocker arm and that broke the rocker arm and the broken rocker arm pushed the retainer down allowing the keeper to fall out.
What valves were used stock?
this makes perfect sense. Hopefully the OP can get answers upon disassembly. So... hydra locked may actually be mechanical binding... damn.
Really sorry to hear this. Just here for morale support! In for updates.
I just recently "finished" a 427 build, and I've had nothing but paranoia bells going off in my head about all the things that "could be" wrong with it, even if it's nothing.
Some more pictures, somehow the intake valve broke are dropped into the cylinder. It is wedged into the head by the piston. Still haven't took the head off to inspect the cylinder.
Head of the intake valve broke off. The stem looks like it sprung up into the intake runner after the rocker broke. Head of the valve is most likely what caused the coolant leak into the cylinder. LLLosingIt nailed it
Head of the intake valve broke off. The stem looks like it sprung up into the intake runner after the rocker broke. Head of the valve is most likely what caused the coolant leak into the cylinder. LLLosingIt nailed it
I’ve never seen a valve stem go up the intake. That’s a first for me personally.
Its impossible to put into words how fast everything moves around during an event like this. There will be witness marks on stuff that shouldn’t have them. Having said that, is there a mark on the bottom of the valve cover, directly above the suicidal intake valve by chance?
Hydro locked #1 cylinder 
