Harmonic balancer weight

[Kevin Johnson]

...
Fun fact: Running an engine at its crank resonance RPM for more than a few seconds can spike the oil temp by 20°or more.

This is completely plausible, particularly for straight six engines with some severe critical rpm ranges.

I think people are interpreting the statement to refer to the average temperature of the sump oil volume rather than the temperature of the oil film in the bearing.

Two sources that might be interesting to read:

The article by Dr. Dmitri Kopeliovich: //www.substech.com/dokuwiki/doku.php?id ... e_bearings See Fig.8 Effect of oil clearance on oil temperature rise.

Pavel NOVOTNÝ
Václav PÍŠTĚK
Jiří STODOLA
VIRTUAL ENGINE - A TOOL
FOR MILITARY TRUCK RELIABILITY INCREASE
http://aimt.unob.cz/articles/06_01/06_01%20(4).pdf See Figure 13 Main bearing journal center orbital displacements.

[1972ho]

It was the fluid damper.

[Newold1]

I have some personal thoughts and experiences with dampers. I personally feel that internal engine balance is always preferred if ones engine can. Reason, there are less rotational, vibrational and reciprocating stresses on the crankshaft snout in an internal balance. I also feel that there is definitely no one type/size fits all as dampers are specifically designed and sized to meet the balancing, harmonic and other stresses created by various crankshaft types, strokes, weights, rpms, firing orders, number of cylinders, etc.,etc. THERE IS ABSOLUTELY NO ONE TYPE, ONE SIZE, ONE WEIGHT FITS ALL!
My advise is if you are putting together and running a higher rpm, higher power and torque performance engine spend a little more and talk to, study and buy an ATI damper. There is a reason almost every major racing program, builder and users buy and use them. It's because they are the best second to none! They are the only dampers my mom let's me use! JMHO

[Dave Koehler]

Well looks like the front snout of my crank broke off today,I was making a few tnt runs and I could hear the engine missing in high gear and on my last run it started to miss early in the run and then I hear a kind of bang.And get towed back to pits and see that my dry sump pump belt is missing and then I see that the balancer is moving around and find that crank is broken just right behind the balancer near the crank cam sprocket.Well that didn’t last to long.

See? If you had not brought up this subject 2 years ago this would never have happened.