[chuckdietz]

there are a few things here one is the timing there is also fuel octane with 10:1 compression 93 octane is right on the edge of detenation then throw in a hot timing setting and desaster as you have it.

[BadBanana]

Maybe an air leak - intake to heads angle mismatch, etc. It seems hard to believe you could do this much damage in 90 miles and not hear it going on !!

[KeithDyer]

Most HE pistons to not handle detonation long enough to look like this, they most often stick the ring pack and pull the bottoms of the pin bosses out and the rod / pin combination saw the block in two!!

I have never felt that modern street fuel (any of it!!) would support much more than 9.5 or so with way short timing (those Vortec heads should not need much timing).

Not sure if the HE pistons do this, but most forged pistons will shrink slightly when you detonate them, that may try to stick the rings in the grooves. And once you pinch the ring lands, oil enters the fuel / air mix and lowers the octane the motor is seeing even more and compounds the problem / damage.

No head gasket leakage?? No "Pepper Specks" on the spark plug porcelain?? That would also indicate detonation.

Take care, K

[Offshore 420]

Sorry, but I can't believe he's going to warranty that engine.
There is NO WAY I would, or just about any other builder. Detonation isn't covered.

[bondo]

Originally Posted by Offshore 420

Sorry, but I can't believe he's going to warranty that engine.
There is NO WAY I would, or just about any other builder. Detonation isn't covered.

Ayuh,.... Agreed,... The owner Smoked that motor....

[WARREN BARBER]

It's odd that nobody notices all the rings are pretty much lined up. The scuffing on the pistons skirts looks to be caused by to tight a fit. Not due to original clearances but do to massive overheating which in turn caused the detenation concerns. who ever put the engine together didn't know what they were doing and probably didn't purge the cooling system. This is the only way this mush damage could be done to an engine in this short amount of time. Unless NOX or just all out racing and no break in period.

[CNC BLOCKS NE]

Originally Posted by WARREN BARBER

It's odd that nobody notices all the rings are pretty much lined up. The scuffing on the pistons skirts looks to be caused by to tight a fit. Not due to original clearances but do to massive overheating which in turn caused the detenation concerns. who ever put the engine together didn't know what they were doing and probably didn't purge the cooling system. This is the only way this mush damage could be done to an engine in this short amount of time. Unless NOX or just all out racing and no break in period.

I am sure the engine being over timed will cause the pistons to run hot and expand and cause this damage!!!

[topwrench]

Look and find how the oil got into the combustion chamber!
I think thats what caused the problem
I dont think it was timing
Looks to me like oil caused the detonation this can happen really fast!
Are you runnind a pcv system?
Also check the valve seals
It could have been timing,but I doubt it.

[Redcar]

i have the same type of pistions 383 60 over with 500 miles on it sound like a break in problem but i just did want the machine shop said what to do but i do have to say that it was running fat for the firts 300 miles

[oldbogie]

Originally Posted by Redcar

i have the same type of pistions 383 60 over with 500 miles on it sound like a break in problem but i just did want the machine shop said what to do but i do have to say that it was running fat for the firts 300 miles

This is classic detonation/preignition damage, the owner even said that he added more timing than what the engine came with. That's most likely what did it in.

Hyper-eutectic pistons are quite intolerant of this as are most cast pistons, but high silicon aluminums including that used in forgings are more brittle and do not transfer heat as quickly as lower silicon alloys.

These alloys also tend to break up, this was mentioned in one of the early replies, if you look carefully at the pictures you can see a crack running from the ring lands into the pin boss. Fortunatly the owner burn't holes through the crowns, lost compression resulting in the engine quiting just in the nick of time leaving him a rebuild instead of a replacement. Pushed a few seconds more, this engine would have been pieces on the pavement.

So when running hyper-eutectic castings or high silicon forgings it is extremely important to stay out of detonation. If you're inclined to push the limits do what the factories do, put a detonation sensor on the engine. It is not difficult to install one such that when it hears pinging it kills the ignition. With a computer in the ignition loop that controls the advance electronically the detonation sensor can be used to back off the advance which is more gentle on the parts than just shutting off the ignition. However, either will save the motor. Detonation sensors don't work with gear driven cams as the gear noise trips them up.

Bogie

[Gus's 40]

You got me wondering about my 383 I have aluminum heads, cam has .480 lift 109 lsa and 230 duration at .50 it is running a little rich right now but seems to run good but I do get oil coming out the breathers

[techinspector1]

Originally Posted by brad33478

He believed me and is covering all the parts/labor

Being an old guy and having been around the block a couple of times, I see this a little differently than others on this board. I see you as an irresponsible "TAKER" like so many others in present day society. If you had any integrity or honor, you'd pony up for the fix on this motor instead letting the builder do the repairs and eat up all his profits from the job. If you're claiming you couldn't hear this motor detonate, you're a liar. Did you tell the builder that you altered the ignition timing? I'm bettin' no.

If I were the builder, I'd tell you to go pizz up a rope.

[prostreet6t9]

Originally Posted by techinspector1

Being an old guy and having been around the block a couple of times, I see this a little differently than others on this board. I see you as an irresponsible "TAKER" like so many others in present day society. If you had any integrity or honor, you'd pony up for the fix on this motor instead letting the builder do the repairs and eat up all his profits from the job. If you're claiming you couldn't hear this motor detonate, you're a liar. Did you tell the builder that you altered the ignition timing? I'm bettin' no.

If I were the builder, I'd tell you to go pizz up a rope.

X100 Very well said.. At very least the OP could pay for parts and the builder put it together for you.

[Redcar]

funny you say that i seem to have the same problem not sure the cause was told might be because high pres oil pump its not alot but it does make a mess

[Gus's 40]

yea mine does to all over the firewall and motor but not all the time, I took the breather off the drivers side and put a pcv valve with a baffled grommet and put a piece of foam filter under it and think it might be to restrictive