Continous high rpm driving, what is safe??
 

If your engine/driveline is in good shape, And you are looking at several hours of sustained high speed travel, What is a safe rpm to stay at?
I know this is a tough Q, But thinking that all is in good shape, engine staying cool, egts low, all that stuff,,
Is 2500+ safe for hours on end------ not towing anything.
Peter.

I asked a similar question about towing (i.e. downshifting and running higher RPM's up mountains, for miles on end)...and got this answer from Dave:


I don't know that I'd run >3000RPM for hours on end, but I'd definitely run 2500-2700 without worrying about it...

Greg

I HAVE run 2500-2600rpm towing. Only thing it hurts is MPGs.

we have asphault pavers at work that run basically the same engine in the trucks, and they run 2900+- rpms all night while paving.

I personally have run WOT 2600 rpm all day w/727 on my '89. it never hesitated one bit, until my stock orig. lift pump went out at 190,000

MMMM, so i am thinking from what i have read here, I am real safe at 2500 rpm all day and night?!!! Have some long miles to cover soon, I usually am about at 2k-70 mph, Nice to hear that i can run it a but harder,
5 sp getrag with 354 rear 2 wd, Seems like i am good for about 80+
Peter.

Cummins says you can run against the governor all day long without harm to the engine. Now to put that in perspective. That is with the original stock setup - NO mods. The original goverened speed being around 2450. As stated above your probably safe at that RPM but watch you EGT's and coolant temp.

Bob