Catastrophic engine failure, suspect pre-ignition (Pics to follow)

[DoctorDex]

Originally Posted by keithmac

From what I`ve found tuning for fixed rate methanol injection 2nd gear is useless, I logged my car on a few 1/4 mile runs and 3rd gear was leaner than 2nd for some reason.

Completely agree. 3rd gear is where I get my most accurate tuning runs. However, I can usually get a pretty good idea of where things stand using 2nd gear. If I get my tune down in 2nd, then I usually just richen it up slightly and then my tune is usually spot on in 3rd. Plus, this saves having to do multiple back to back 120 mph pulls on public roads.

Originally Posted by keithmac

I suggest the first time you get on it after a tune you keep a beady eye on the AFRs in the higher gears. I`m building an audible warning circuit for when afr`s drop leaner than 11.5:1 with meth active, this will also kill the boost controller.

Sounds like an interesting setup. How'd you rig it up? All I have is AFR & knock displayed on my steering column, with an audible knock alarm, which is emitted by my pda.

[silverpearll]

Originally Posted by DoctorDex

I got working on pulling the motor today. The motor is _nearly_ ready to come out, just need to get my hands on a cherry picker, which won't be possible until this weekend.

One thing I was't sure what to make of was the fact that when I drained my oil, there was more coolant in my oil than there was oil in pan. In addition, there was fair sized chunk of metal that became lodged in the drain hole.

I bought a car that had this same condition when draining the oil. Turned out one of the pistons had come apart enough for the wrist pin to be exposed, which in turn punched a hole in the side of the cylinder wall into the cooling jacket. The motor would only turn over so far because the wrist pin had actually lodged itself into the cooling jacket. Most of the piston was in the oil pan. The head was luckily reusable. Good luck!

[DoctorDex]

I pulled the oil pan off today and I was utterly amazed by the degree of damage to the block. Rod #3 is completely destroyed and there is only a small portion of it remaining. There is a large hole in the wall of cylinder 3 and the 2 bolt main is broken and the bottom of the block is blown out. The head of piston #3 looks like it is buried in the head so I was unable to get a good view of it without proceeding further.

I've included some pics.

[DoctorDex]

More pics.

[oohnoo]

Shit!
Well that's that then. Talk about catastrophic failure.

[DoctorDex]

The damage seems very similar to what FWombat described and I think it adds credence to his theory.

[Dj4play]

Originally Posted by DoctorDex

I pulled the oil pan off today and I was utterly amazed by the degree of damage to the block. Rod #3 had completely exploded and there is only a small portion of it remaining. There is a large hole in the wall of cylinder 3 and the 2 bolt girdle is broken and the bottom of the block is blown out. The head of piston #3 looks like it is buried in the head so I was unable to get a good view of it without proceeding further.

I've included some pics.

wow, factory rod bolt failure then
fasterners failed causing the rod cap to come off sending the rod into oblivion. Not sure i agree with the porting of the block though: ) let me know what you want to do. you block is now junk

[Gray Haze]

Originally Posted by Dj4play

wow, factory rod bolt failure then
fasterners failed causing the rod cap to come off sending the rod into oblivion. Not sure i agree with the porting of the block though: ) let me know what you want to do. you block is now junk

Ummmm Where do you see fastener failure? The rod cap is still there!

[oohnoo]

The jedi master has spoken.

Originally Posted by Gray Haze

Ummmm Where do you see fastener failure? The rod cap is still there!

[DoctorDex]

The rod appears to be have torn/bashed off the underside of the piston and there is only a 1/2 an inch of total rod material left on the base of the rod (on the crank end). There are a number of small pieces of the rod in the oil pan (along with a couple hand fulls of other various metal chunks) and I am unable to account for all of the rod pieces as it looks like it literally exploded.

Edit: An alternative explanation would be that the entire underside of the piston came off, releasing the rod. The rod then bashed a hole through the side of the block while it destroyed itself.

Assuming this was caused by the wasted spark triggering the methanol charge in my intake plenum, what steps can I take to prevent this from re-occurring?

I know I can advance my base timing, jack up my fuel pressure, put the stock crystal back in my ECU and switch to a direct port meth system. I suppose a stand alone or other method of true timing control wouldn't hurt. How about cam gears? ie. retarding the intake cam. What would retarding the intake cam 5* do to the powerband? Are there reasonable alternatives to a wasted spark ignition system, other than using a distributor? Does anybody have any other ideas I'm missing?