will JB weld fix this??

[exdeath]

Originally posted by: Squisher

Originally posted by: pac1085
picture of piston removed from motor:

Text

What exactly happened here? Did the ring fail first?


btw - you better throw some metal filings into that JB Weld

Assuming no detonation (doesn't look like it, the crown is pretty clean otherwise) I'm guessing that being "one last run", it probably heat soaked and seized in the cylinder wall from expansion and sheared the lands/rings off against the walls.

One of the back cylinders?

 

[pac1085]

It was cylinder #4, which is last on the fuel rail

i have a data log of the run and my afr was right where I wanted it at 11.5:1

timing - I may have been running a bit too much, but not WAY too much (19 degrees).. 19 psi of boost.

when I started the run my coolant temp was 200 (the thermostat is stock @ 190) but it rose to 240 degrees by the end of the run

pistons were the stock ones, Mahle's ..forged.

 

[exdeath]

Originally posted by: pac1085
It was cylinder #4, which is last on the fuel rail

i have a data log of the run and my afr was right where I wanted it at 11.5:1

timing - I may have been running a bit too much, but not WAY too much (19 degrees).. 19 psi of boost.

when I started the run my coolant temp was 200 (the thermostat is stock @ 190) but it rose to 240 degrees by the end of the run

pistons were the stock ones, Mahle's ..forged.

And your temp sensor is probably located at the front of the engine?

 

[pac1085]

No, it's actually in a flange right above cylinder 4 on the back of the head

 

[Silex]

Ouch...that's what happens when you go with FI on an NA car and not run on a built engine especially on 19psi boost. Gotta pay to play. So what quarter miles times were recorded?

 

[pac1085]

It wasn't a NA car, the 1.8T's are turbo from factory (albeit a small turbo)...hence the beefy forged pistons... ~9.2:1 compression. most people bend the rods before the pistons go, though.

I was only able to pull off a 13.3 at 102 mph..on the run where I blew the engine...it blew before the end of the track too... here come the ricer excuses..I did hit 107 & 108 Mph on two earlier runs that day, and I'm pretty confident that run would have been in the 12.8-12.9s if it didn't blow.

i need to work on my 60' next time too as I was getting 2.1's - the car is AWD but spins all 4 when you launch it...I had good tires on too (pilot sport ps2)- should be able to get those down to 1.7's.


New motor is at the shop being assembled - I'm going with a 2.0 stroker motor - wiseco forged pistons with ceramic coated dome, coated skirts, 8.5:1 compression, forged vw ABA crank, scat forged rods, engine will be torque plate bored, etc, everything balanced. i will be getting it professionally dyno tuned this time, should be good for mid-11's when it's done (I need a bigger intercooler and water/meth injection too)

 

[PlasmaBomb]

Ouch poor piston.