So my buddy’s c10 . 5.3/s480 @18 lbs . 93 / meth/water . What would cause this ? Went lean ? Had it tuned . Been done for a while . 2nd time at the track first run .

 

Maybe the head lifted.

 

It was obviously detonating pretty bad on all cylinders in the picture. Without knowing the actual tune, fuel pressure, whether the water/meth was actually spraying, etc., we can only speculate as to the cause of the severe detonation.

 

How can u tell it was detonating in all cylinders? The only thing that changed is he bought a 2 step but I guess he didn't use it at the track , but he was messing around with it on the street the day before

 

" he bought a 2 step but I guess he didn't use it at the track , but he was messing around with it on the street the day before".
Way too much info missing to make much more than this being a possibility.

 

Depends on how it was tuned.
For example, I bought my buddies car who had it dyno tuned, ran great, no issues.
When I made a full pull thru all the gears say 20-150mph I realized there are a lot of issues that will pop up that don't on the dyno.
Fuel pressure dropped off, threw the belt off, boost controller referenced incorrectly, several problems popped up which never happened to him because it was only ever run for a few seconds at WOT on the dyno.
Post the tune for starters, describe the engine combination, describe the current fuel system, W/M content, when does it come on.
Willing to bet timing was greedy or fuel pressure dropped off at the top end.
Assuming this is on a Holley system, no safeties were in place?

 

Did you have a log to look over?

 

Maybe it is just the way the pic looks on my screen, but that looks like a lot of speckles and pitting all over the combustion chambers and valves. I don't see any of the melting you would get with pre-ignition, so it looks like detonation to me.

 

Haven't provided enough information.

 

I would imagine 93 and high boost even with meth/water you were a little on the edge, and if you don't have like an oil sep on the PCV valve, wasn't much room for error.

 

What's the timing at?? Looks like they were a little greedy with it and motor said I can't take it anymore

 

Looks like a timing issue.

 

That’s exactly what mine did when I had fuel slosh and it leaned out at 18 psi.

 

I think that's what happened. Gonna look into a baffled tank or a hydro mat . It's got twin 340s in tank . Stock tank . First turbo build so it's a learning curve

 

Got an another 706 head . It's down golens swapping valves etc . He originally put bigger valves in when he did motor

 

what did the plugs look like?

 

Its hard to tell, but looking at the plugs in the head from the shot, the timing mark is in a pretty bad spot, which is why I said timing.

 

Too far up the strap from the bend?

 

Hard to tell from the pictures, but the cylinder in question looks like the timing mark is on the grounding strap near the body, below the bend.

 

I thought for pump gas if the mark was closer to the base nearest threads that it meant the timing was low if anything?