Let me paint the scene for you. I'm driving my 70,000 mile '94 vette down the road behind a truck/horse trailer going all of 20 mph and I decide to pass. It doesn't take much at that speed, so in 3rd gear and about half throttle I make my way around him. I backed out and shifted into fourth around 50 mph only to be greeted with a violent shaking and smoke out the back end of the car. I have never used anything but Mobil 1 synthetic and only had it to the track once in the year that I've had it. I tore the motor down and I had one twisted/bent con rod with a broken wristpin in the #8 cylinder and no piston. The piston (in pieces of course) had made it's way down to be beat around by the crank until it locked up the motor completely. I am rebuilding the motor now with a different stock crank/rods and forged pistons. I have always heard of how tough the LT1 bottom ends were and I never expected to see one grenade like that in a stock setup. I'm an ASE master tech and I worked for Waco PD fleet dept for a year when they had a lot of caprices and never saw anything like this with an LT1. Do you guys think that was just a fluke or is there something I don't know that I can do differently with the new motor. I've got a ZZ9 cam and a set of mildly ported heads to put on it and I'd like to be able to spray in the future, but after what's happened, I'm a little worried. I'd like to get some advice from people who've been around them a lot. Thanks.

 

Any kinda of debris get into the oil? That will make it go real fast.

 

if there was stuff in the oil, I don't know about it. it's so hard to tell with all the pieces of piston in there now

 

Sounds like a fluke. I dont hear about LT1s blowing up at low rpm.

 

Sounds like a fluke to me also. Stock crank should be fine, forged pistons are always a good idea, but why not some Eagle I beam rods? Hell even the H-beams aren't that expensive.....

 

Its not completley unheard of, some times you get a weak motor, theres cars on here that have hit mid 130MPH+ in the 1/4 on a stock crank, yet I know someone who broke one in a all stock 95 Z28 with 80K miles just sitting in traffic. So yeah its a fluke, but it happens

 

Maybe you lost that injector which then detonated the life out of the #8 piston.

 

That's a thought, but the piston didn't look like it had been hot at all, just like it broke. I think maybe the wristpin borke first, but I'm just not sure why. I was talking to my stepdad and a friend of his broke the crank in his 96 Imp just tooling down the freeway, so I guess this stuff happens now and again.