What can kill a SHO engine?

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A SHOtimes reader wrote about his experience with a costly engine rebuild due to a scored/galled cylinder wall. My money says that it was #2 cylinder. There are only three things that can kill these engines:

  1. Over heating. This will kill any engine.
  2. Nitrous oxide. I have a close relationship with this problem.

(Ed. Note: More recently, it is apparent that SHO motors in good shape and prepared properly do take well to dry nitrous kits.)

  1. Broken catalyst, caused by a stuck thermostat and concomitant overheated converter.

I have rebuilt seven engines due to converter failure. When the thermostat sticks open, the computer keeps the engine in a rich mode. This kills the fuel mileage and also overheats the cats which burn off the extra fuel that doesn't get burned in the engine. When the cats overheat, they break up along the leading edge and the pieces fall to the bottom of the chamber.

Now, what do you think happens to these pieces when you buzz the engine up to 6500 in second and take your foot off the gas? The intake manifold becomes a huge vacuum chamber and the pieces get sucked right back up into the engine! It's like dumping beach sand into the throttle body.

If you're concerned that your catalysts may be damaged, check the How to inspect your catalytic converters page.