The culprit

holy hole batman!

bummer dude

Sorry man,Isn't that Moter fairly new?

What could have caused that to happen ?

Oh man, that sucks. On the bright side, you'll be ready for next year!

Hmmm.... looks fine to me.

Isn't that where the oil goes?

Damn & Keith Black pistons to boot! Sorry Jimmy . Sure glad you still came & spent the weekend with us. Wouldn't have been the same without you.

That's fairly surprising figuring KBs would be the last to go...
Hopefully the rest of it isn't dead but anytime you need a taxi ride, I'm in - it was a good road trip with you along. And only a warning from the UHP!

Holy crap!! WTH went through that??

That can cause it to run a little rough. Ouch! Broken valve?

Broken valve would leave indentations everywhere. It almost looks like it leaned out and burnt through the piston.

Shit sticks, Bubba! No bueno. How many miles on that engine? Pre-detonation? Time to Subarize that puppy!

Ouch, that sucks.

Looks like a little detonation with the all of the pitting but engines usually can last for quite a while with some pinging. Pre-ignition is usually what causes holes like that, unless it was a purely mechanical failure (crack) and some detonation hammered it apart. It just doesn't look very melted. Perhaps you were running a little on the lean side so the pistons were a little warm and the timing was advanced a little too much?

Man, I mean maaaan. That will not stand. Time for drawing a line in the sand.

I am really sorry to see this. Thinking the load of the luggage rack might have done it? But it also looks cracked but not especially melted. I hope an expert chimes in.

I almost took the bait there....

Dang dude, that sucks!

Not knowing the situation, this could have been a lot worse. What do the valves and head look like? Maybe you need just one new jug?

Will this be normal for the -6 motor your building

total bummer......Gald you still had a fun weekend.....

Click to view attachment

Bummer,man.
'Engine seems a quarter down on power'
This is my piston.There are many pistons like it,but this one is mine.

What was the fuel being used at the time of failure?<-
Has the head been inspected for cracking due to the temp spike?
Have the exhaust valve seats become loose?
Have the exhaust valves been cracked from the high egt?
Have any of the other cylinders been damaged by the shrapnel?
Half the time the rod gets loose from the piston and flails around in the crankcase .

http://www.914world.com/bbs2/index.php?sho...293242&st=0
http://www.vw-resource.com/octane.html
http://www.dtic.mil/dtic/tr/fulltext/u2/b807149.pdf
http://www.contactmagazine.com/Issue54/EngineBasics.html
http://diversiorum.org/sape/pilotage/Engines/index.html
Mix/Load/rpm/air temp/altitude.

/

I hope you can post a complete autopsy; pics, details, causes. And the extent of replacement parts. Maybe we can learn something from this

Of course, it was great Jim carried on and made the RRC anyway.

Injectors are being tested now. Report back tomorrow.
New 123 dizzy was set at 27 degrees exactly.

I'm hoping the injectors tell a story. They all tested good prior to install. I'd hate to have a problem with the 123. I may take it to Ed Fall and have him double check the curve.

The rest of the motor looks great. It doesn't look to have gotten that hot. Heads and other pistons still look new.

That's what you call a piston squirter :-)

That looks awful. Glad you still made it to RRC

Expect low compression in that cylinder...

Bummer, hope to read what the cause was here so it can be avoided by him and others!

Could have been worse....I was troubleshooting a friends car which wouldn't start for her.

I had her crank over the motor while I stood over it looking around and there was a loud explosion as the cast aluminum valve cover blew apart, how I didn't get hit by chunks of sharp metal was amazing.

Turns out one of the pistons had a hole in it and that cylinder finally lit and the combustion gases went thru the hole in the piston and found the weak spot which was the valve cover!

Report from the injector shop came back just now. #3 down in volume and spraying a straight stream. It appears that's what holed Jimmy's KB.

I think he was seeing his doctor about the same issue.....

Who do you use got injector service? Thus looks very much like what happened today my motor. I either lost an injector organizations it was clogged. Want go fix before I install on my new motor.

That looks more cracked than melted, wondering if you will find a chunk somewhere in the case.

How about some details on your engine, Jimmy. Size, compression, modifications, engine hours, etc. What was the performance like up until it took a crap. Number 3 piston?

That's a compression release!

Now that's......

Engine: Late model D-Jet, 2056, OEM cylinders bored out to 96 mm. Keith Black pistons, Hastings rings.... New 123 ignition, new bearings, etc. The car was running great, lots of pep. Motor had maybe 2K on it, never took it on any long runs, just around town. Freeway short distance.

This was the first real test of the new motor. One injector decided it had enough.
fked up my piston. It could have been a lot worst. I have 4 new injectors, they will be going in the car.
Bottom end being checked for any junk that might have gotten in there. It will be checked fully.


Car will be up and running soon. Won't be long I'll put it to bed for the winter.

Well,the fuel system has always been a no compromise repair,from rusty tank to aged plastic lines.
Lost a few 14s to the failure of any one part,and a single speck of debris that holed a piston.
A total rebuild then,is the path to hassle free running,a cleanout and replacement of rubber lines that appear ok externally.
An impressive hole and a lesson that warns those that might cut corners,'re+re your fuel system'.
A fuel system depot for all your needs might earn a dime,globally.


/

Damn Bubba! Nothing but the best and this happens. Go figure.

.........that looks like SUPER LEAN under load

It was super lean cause of the bad injector, I got the car back and its running great.
Glad to have it back a running..

Good to hear it is back up and running.

Awesome! Hope to see you soon

Enjoy.