Depends on the engine. A little Jap 4-banger is designed to run and run and run and run on the surface of the sun before it stops. And a stock jap trap isn't going to throw a rod unless you revv it waaaaay up or loosen a rod cap.
How about using a straight 6? They're plentiful and can't take a lot of RPM. Or a furd 2.3 4-banger like used in pintos and dirt racecars. They'll revv way up and go "pop" if you run them out of oil at high RPM.
Basically if you want a rod failure, you have to find a motor design thats prone to rod failure and aggrivate it with excessive RPM, loose parts and poor lubrication. Works for my friends!
Now you can get more spectacular results using an american V8, but I'd have to kill you for ruining an engine I might need. Especially pre-77 pontiacs.
