Does this look broken to you? [18R-G Piston tops]

[demios]

So I had a Timing chain failure and my valves decided to bounce and bend on the tops of my pistons. They don't look too bad to me. A bit of a clean up and the should be okay, but that's my uneducated opinion on the matter.

Piston #3 took possibly the most damage and you can see it took a bit of metal off in the last photo.

So I'm putting the question out there for you guys. Does this look broken to you, and if so, what should I do to make my car go broom again?

Piston #1

(Click to enlarge)

Pistons #2 & #3

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Piston #4

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Closeup of #3

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[Celica RA45]

i would say that most of your valves are bent .so you would need to check that ,but the pistons look ok even with the little tap marks

[allencr]

Broken doesn't help, but I can't see anything broken, just a missing chip.
Worry about the land pinching the ring.

[CELICASUPRA7M]

fix the head/valves up and smash it back together.
broom broom!

[demios]

6 out of 8 valves on Demios' engine suggest that they are bent, so yeah. Fixing up the head is a given.

Just wasn't sure what sort of limits are on piston damage. Didn't want to think that everything was fine only to find out that the little dints caused hairline cracks and catastrophic failure. Better safe than sorry, you know?

Still need to find out why the timing chain stopped doing it's thing, but that's a job for another day.

Good to know that this should be sweet to go with a little bit of a clean up.

[Javal]

Clean the tops up as best you can and inspect for cracks.

I would say that these pistons will still be ok for another round.

[Sam_Q]

how about a proffesional crack test for the pistons, using a UV method they might even be able to do it without you taking the thing apart more

[river]

Hi,

I must admit, if it was my engine, I'd be getting the pistons professionally checked or replace them. If there is a weakness in them they will fail and you'll have to pull the engine and replace them.

Of course, if it's just a hack engine which you aren't expecting much from or don't really care if it has a long life, then sure, take the chance.

seeyuzz
river

[MWP]

To have them checked you need to pull em out anyway river.

I reccon there is a very low chance they are damaged, so better to just run them and pull em out again if problems arise.

[w810sc]

I've had the same problem on my 2T-G. All of my pistons had the same markings as your piston 4 but with more aggressive impressions, the intake valve just kisses the pistons intake valve relief. My problem was running the cams at 106 degrees LSA.

I removed the head and took the cams out so that all the valves are shut, poured petrol in the combustion chamber (facing up) to check for leaks around the valve seats and if any valves where bent, I also poured petrol down the ports and checked for leaks as well. None of my valves where bent. The piston received deeper valve reliefs and I smoothed out all sharp edges as well as taking away material off the piston to drop compression.

[dale30]

It takes a lot more than that little tap to hurt pistons..Just clean the sharp edges up and itll be fine.

[demios]

This is what happened to the valves, if anyone's interested.

Cylinder #1

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Cylinder #2

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Cylinder #3

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Cylinder #4

(Click to enlarge)

[dale30]

I got some just like that.!!

Stupid timing chain didnt like about 9000 free revs...

[tomo1ggte]

i had somthing similiar happen to my old nissan pintara. cleaned everything up and put it back together, after 5 mins of having it started it went BANG and blew a hole out the side of my motor. you really should get the pistons checked for any hairline cracks

[Javal]

Those valves do appear to have taken a pretty bloody solid hit, i retract my previous statement and suggest you get those pistons checked.