cliffyk

I had assumed that the rods were observed to have failed under a compression load (as in a whole bunch of chamber presuure pushing the pistion as in comes up on the compression stroke); vs. a tension load (as in top of stroke w/ valves open).

As to the OP's situation, he has my condolences for his loss. However, pushing a stock 2V bottom end to 362/427@5k at the wheels (approx 410/482 at the crank), is playing near the edge.

When Ford decided to bulid a 4.6L 390HP engine ('03/'04 Cobra) they moved to forged internals and 4V heads--not just to spend more money but because they knew the limits of the 2V with its cast metal internals...

thunderhorse

I was running the KB recommended spark plugs at a .035 gap (also as recommended). It's my understanding that this really is a random occurance. Eric's wife who also has a 2V is running 440rwhp on her setup no problem, stock internals and everything. The castings are just random and really not engineered to be pushed like I did. Again, I think most GTs with stock 2Vs could probably handle it, but mine didn't, and it sucks.

I definitely ran the car hard before through 3rd gear.. I managed to dish it out to a few vettes along the way. It seems like it was just the time that it gave out. A buddy of mine posted my story on svtp, and Mike from KB claimed if it was the tunes fault, it was because of longtubes and I shouldn't have trusted the longtubes or some bs like that. I like KB a lot, and I don't think it was the tune itself, but I thought that excuse was kinda lame.

There were a lot of people on hand that day, quite a few with notable experience, and it really was the consensous that the engine just quit on me.

It's definitely depressing, considering it'll take at least the better part of the summer for me to upgrade and install, but if there was any way this thing was gonna go out, it definitely picked the best place and time. Eric was really nice about, the no one charged me and one of the guys there even used his AAA to get me a free tow.

lizzyfan

You need to get in contact with KB!
I know someone that had the same issue and KB paid for a new short block!!!

-ToXiC-

That sucks dude.

Stevecooper

Takes a tune differently, I am not sure what you are trying to convey?

That being said can the OP post a data log at the time this happened? I also believe that Eric uses an AFM1000 or a Lambda Pro at his place so I would trust the data.

JT76

I was filming this UGHHH got hit with a piece of ring, the noise scared the crap out of me!

Opportunity to go bigger and better!

Stevecooper

He is not saying that the "pressure" from the 9PSI KB is the problem. It was the cylinder pressures that caused it. You can not make more power with out higher cylinder pressures, pressure is what is pushing down on the piston.

96paxtonstang

You wont have to worry about it so much with a centrifugal supercharger because you dont make boost immediatley like a KB supercharger. you could drive your car forever with a centrifugal supercharger as long as you dont hop on it hard without having a tune done first. because you will only make boost with your climb in RPM's you'll notice right away that you will not get into boost a whole lot actually unless you are really intending to. so dont put the install on hold to long it is totally worth it and you wont run into this problem as long as you dont rail your car without a tune.

Hangwire

Stevecooper - I understand 100% the difference between intake manifold pressure and cylinder pressure and what he was trying to say. When I say "pressure" I am referring to cylinder pressure. Have you ever heard of Inertia Loading and how it is affected by forced induction? The cylinder pressure caused by this supercharger did not blow this engine.

Thunderhorse i'm in the same exact boat here. I ****ing love KB and trust them A LOT but I think that was a lame *** excuse too. I would really push this issue and get somebody from KB on the phone. The way they swear up and down about their tunes I would personally never expect my car to be showering coolant and oil down on the dyno. If they stand by their tunes that much(and they do if you read their documentation) then they need to stand by them and buy you a brand new shortblock. If its the longtubes fault they never should have agreed to tune your car. Thats fault on their end IMO.

This being said I still <3 KB :P

tbirdscwd

I wouldn't be so quick to blame this on the tune. Bad tunes cause detonation which causes piston damage most often......rods break under too much power/stress or if they already have been compromised by a hairline fracture or something else. I highly doubt the KB tune was bad enough to smoke your rods on the first dyno pull. Did you or anyone else hear any detonation during this pull? I don't hear anything in the vid, although it can be hard to hear sometimes. It would be interesting to see the datalog.

Chances are your engine was gonna go once it was making a certain amount of power under a hard enough load no matter what tune the car was running.