Gentlemen,

Should 45 year old harmonic balancer's be changed out or not a problem to worry about on a 1960 292??

Are they known to come apart unexpected and cause damage to other components in the engine compartment??

Thanks for your help
Monte

 

Monte,

There's no quick answer to your question, unfortunately. I know of many engines running older dampers that have lasted with no problems. I do know of some cases where there has been a problem. As a rule, they do not come apart; rather, the outer ring slips and makes it very difficult to set the timing. (Obviously at this point they aren't serving their purpose as a vibration damper anymore either.) In certain early Chevy small blocks where the dampers aren't retained by a bolt, they tend to come off, & can cause damage on occasion, usually minor.

The few times I have seen/know of dampers "exploding" were for one of three reasons: 1) being revved beyond their design limit 2) being installed with a big hammer instead of the right method, & cracking from the blows 3) damage caused by a cracked crankshaft (hard to tell sometimes which came first, the damage to the crank or the damper)

If the damper is already off the engine, here's what I would do. Clean it, visually inspect it for cracks in the ring & hub, look at the material between the two for signs of splitting, "slipping out" between the hub & ring, or deterioration; check the keyway for proper size; & check the hub bore & crank for signs of galling. If everything looks OK, it likely is. You can ask a machine shop to Magnaflux the damper for cracks, if you want to go the extra mile.

Lastly, I'd verify that the damper mark is still really at TDC, & if it is, call it good.

If it's still on the engine & running fine, with no vibration issues, I woudn't worry about it.

Mike

 

Mike,

Thanks for your great write-up. I think I am good shape.

Buddy of mine has a ~1970 Chevy 1/2 ton pick-up with a 6 cylinder and his let go in the engine compartment with only putting a dent into the wheel well. I have replaced just about everything with this 1960 F-100 4x4 and it made me wonder if I should change out mine before something catastrophic goes on under the hood.

Thanks again!

Monte

 

Monte,

I forgot to mention that various places can rebuild your damper if needed. A lot of the T-bird vendors can arrange to have it done (due to the 'Bird Y-block damper scarcity)- but it ain't cheap. I don't know offhand if the garden variety damper is still available new from anybody like NAPA, or the Effie vendors. ATI makes a performance version of a Y damper, but it's close to $400, & overkill for anything but racing.

Straight sixes tend to eat dampers due to their inherent crank imbalance & the torsional effects of the longer crank. They don't normally fall apart though, just slip. I'm glad his damper didn't cause too much damage.

A good friend of mine was badly burned from a damper exploding, cutting fuel lines, which sprayed alcohol on the headers (pulling tractor), which then ignited & sprayed down the back of his firesuit. He had just climbed off the tractor & pulled his helmet & firesock off- tractor was idling... cost him about two weeks in the hospital, multiple grafts, & a $20,000 engine which proceeded to finish wrecking itself (along with engine #2 warping a blower rotor) while we were trying to get the fire inside his suit smothered. I'm kind of particular about dampers now.