What happened possibly????

[popcorn popper]

In auto engines pre ignition is caused from excessive detonation in which the uncontrollable flame front develops a hotspot on piston which in turn ignites the incoming charge before plug. Detonation can not be heard in auto engine however pre-ignition can usual be heard as a pinging sound.

 

[moyiesledhead]

In auto engines pre ignition is caused from excessive detonation in which the uncontrollable flame front develops a hotspot on piston which in turn ignites the incoming charge before plug. Detonation can not be heard in auto engine however pre-ignition can usual be heard as a pinging sound.

Other way around, but I agree with your premise.

 

[DRD]

Other way around, but I agree with your premise.

Yup, you should hear what it sounds like in something with a little size to it.

 

[popcorn popper]

Engine Basics: Detonation and Pre-Ignition by Allen W. Cline Wrong go here! Detonation is what happened! And yes the audio part should go the other way!

 

[moyiesledhead]

Engine Basics: Detonation and Pre-Ignition by Allen W. Cline Wrong go here! Detonation is what happened! And yes the audio part should go the other way!

You seem to be making my argument for me. You linked it....I'm just quoting it.

"Detonation causes three types of failure:
1. Mechanical damage (broken ring lands)
2. Abrasion (pitting of the piston crown)
3. Overheating (scuffed piston skirts due to excess heat input or highcoolant
temperatures)

A hole in the middle of the piston, particularly a melted hole in the middle of a piston, is due to the extreme heat and pressure of pre-ignition."

Probably one of the most confusing and misunderstood engine related failures there is!

 

[popcorn popper]

Yes I see what your saying! The bottom line is deto.was the start of the whole deal I guess is what I'm trying to say!

 

[mighty1000]

Wow I don't know where this thread has gone? I'm only seeing two pages and the first only has three post and then the second page starts at #21. Where is #4-20, been haveing this issue lots with this on tapalk app lately.

 

[mighty1000]

Hey all thanks for the input, the sled was running like crap, the plugs are correct for the sled BR9EYA's. The domes are mint no signs of lean condition on it, still nice and brown&oily, not even an ounce of pitting. I'm leaning towards bad fuel with too many additives add to it to try and make it better.

 

[mighty1000]

I will post some more pics but it never seized or scuffed the sides of the piston. Just blew the hole through the top. That's it

 

[Shadam]

so the bottom end is a schrapnel zone ???

 

[mighty1000]

Nope pulled it apart today just to be safe and clean it out and check the bearing and everything looks good.

 

[popcorn popper]

Glad you got it figured! Sorry for all the jibberish but more often than not bad fuel is the issue!sorta what I was trying to say!

 

[mighty1000]

No prob thanks, I was just seeing if anyone has seen this before. Because its a first for me.

 

[popcorn popper]

The old fan cooled machines would do it quite abit. Most early fans were high compression and everyone on the farm had a tank of purple farm fuel. No one ever told them that hi test was a must after they started lowering octane in fuel. Also the fans would spit a fan belt and boom just the piston you have. Check your sled that you never had a coolant air lock or thermostat stuck. Typically it will skid the piston but once in awhile you get what happened to you! Was this first ride of year?