ISB 6.7's are actually rated at 4200 RPM overspeed for up to 15 seconds by Cummins. I imagine that ISB 5.9's have a similar rating. Throwing a valve is the most likely thing to occur.

Snap tests are effective. Stock engines should not smoke when the accelerator is snapped. Even my first gen stock wouldn't smoke noticeably when snapped. But almost any modified truck will.

 

when we build the race caar motors we take them off idle and run them up the whole range of the RPMs trick the engine builder of grave digger monster truck and most circle track motors around here but he builds and sends all over the country.showed me 400-500 incraments as far up as you want and the same back down stop at each step for a few secs and move on up or down which ever way you are going

 

The way a lot a these guys are runnin big sticks and boxes on stock turbo's I could also see a meltdown being problematic here with this test.

I know these trucks are completely capable of doin a lot a things that I won't do to mine and this takin it to even what the tach calls Redline is one of them. I don't take my truck to the pulls or the drag races because I don't run it like that and now the government wants to make me do it . Somethin wrong with this theory.

I'll hook up to 30,000 pound plus trailers all day all pull em through the mud n weeds but my truck has never been over 1100 degrees on the pyro or been revved over 3000 rpm's in it's life since I bought it off the show room floor. I bought it for a work truck, not a hot rod and that's the way I'd like to keep it.