440-3 redline/maximum safe RPM

[The_Handier_Man1]

From: 70winnie  (Original Message)
Sent: 5/28/2005 9:07 PM

Anyone know where the redline should be on a 440-3?  Whoever replace my engine added a tachometer with a user-settable red line, and somewhere along the line I bumped the little knob that sets it.  I'd like to know how many RPMs I have to play with!



From: denison
Sent: 5/29/2005 11:19 PM

Your torque peak, where the engine is running most efficiently is about 2700 or 2800, which would be about 55 mph in high gear. The engine is probably safe to 4000 rpm, (even being as long out-of-the-box as it is), which would be perhaps over 80 mph in high gear, about 55 in second, or about 35 in first. I think. The ratios wont come out nicely, since there would be a large amount of loss in the torque converter in high gear.
I dont know that your radiator fan and belts and water pump bearings would like spinning that fast for long.
I dont think I have ever had mine above 3600 rpm, and that was only briefly, getting a run for a long up-slope. One reason is that running the engine faster doesnt make a big difference in horsepower or acceleration.
As a street rod friend put it; "Keep that big block mopar below 2800 rpm and it will never let you down."
The rpm at which the engine would come apart is probably above 5400 rpm, and with its 30 year old valve springs, it might have valve float before it got turning that fast.



From: 70winnie
Sent: 5/31/2005 2:19 PM

Thanks Dave, I'll try to keep her around 27-28.