Rpms

In conclusion.. How would you manually get a 100,000 lb load up a mountain? Youd get a few thousand helpers and everyone just kinda tug on the rope, right?

When you slow down and just let'r rev for 20mins up that 12% truck killer.. Youre putting millions more cycles into this job. Essentially cutting the effort level of each individual pulse into a fraction. Everything is easier at less speed, less load, and more rpm.

Be patient and let her breathe, your truck will live to pull another day.

 

I think it has something to do with the oil pump being closest to the flywheel where oil pressure will be greater then all the travels it has to go through to get to the front of the motor.

That's what was taught in school anyways.

I agree on the lugging of the engine being hard on bearings. They suffer the most wear at top and bottom dead center. Low rpms isn't good.

But technology is ever changing. That may not be the case these days.

 

Excessively high rpm would likely present itself as wear in the cap side of the rod bearing, and failure would tend to be the rod bolt. the piston mass needs to decelarate as it approaches TDC and it tries to fly off into the head, creating huge tensile loads that the rod and cap fasteners must endure.

Sidenote- on ragged edge gasoline race motors, broken rod bolts are almost always when someone lets the throttle snap shut after an over-rev. The intense vaccuum ontop the piston, when combined with tensile load from tdc decelaration, overwhelms the fastener.

Too much cylinder pressure only tacos the top half of the road bearing so thats a pretty easy clue when that side falls out.

I havent seen every motor by any means but i have seen oil pumps at the #1 end, and i have seen external belt drive dry sumps with a mid engine feed galley, and the pattern of wear being worst at cyl1 and least at the flywheel end was consistent. Now a bad injector or oil squirter or whatever else could certainly make some funky stuff occur in just one hole. But the crank's torsional strains are pretty well known and quantified in the engineering texts. They call it a harmonic dampner or balancer and thats what it does.. Try to dissipate the washing machine like torsional pulsations going down the length of the crank. That thing has a tough job.