View Single Post
Old 08-28-2014, 10:47 AM   #13 (permalink)
user removed
Master EcoModder
Join Date: Sep 2009
Posts: 5,927
Thanks: 877
Thanked 2,018 Times in 1,302 Posts
Originally Posted by Frank Lee View Post
I'd say you not only don't want the damaging loads on the crank and rod bearings and cylinder walls, you don't want the bucking and jerking. That's tough on the motor mounts too.

Simplest thing is to operate above the lugging threshold. If you are gentle on the gas pedal you can even operate down in that lugging rpm range if you only lightly load the engine. So if you're in 5th gear at 20 mph and you step on it to accelerate and it starts bucking and protesting, back off on the gas. You may still be able to accelerate but at a very gentle rate until it reaches a higher rpm.

If I was certain I wanted to operate in the lugging rpm range and fix it, the first thing I'd do is add flywheel mass. I don't think adding oil pressure would help. And if this low rpm operation is happening because of a tall re-gearing, I'd look at whether a new cam could be ground to optimize the engine for this new low rpm range.
Precisely stated and I agree 100%

  Reply With Quote