Revving unloaded
 

Opinions....its probably not a great idea to rev these motors up past 3K unloaded....is it? I mean, I'm sure this is done all the time when puffing out smoke etc. But does it do any harm?

Great question!

It hain't go hurt injune to ref u p a litle bit. Gov will limit exposure. Question is why you need to?

I don't need to...I just see CTD owners doing this often. Its all over this website....people revving their engines for the sake of blowing black clouds.

Mine clears up if I rev it up...I have to lug it to make it smoke.[coffee]

I doubt it will hurt it. But it way expose some weak links in you engine..??? I know I have had mine into redline racing someone... she still ran fine, just left a nice little birth mark out of her blow-by tube when i parked it after... but whos doesnt.

It will not hurt it at all. Cummins calls this 'high idle'. The stock engine can tolerate about 4200 rpm's without damage. You won't get much more that 3500 if you set a brick on the padal.