Damper Question

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SLC Duster Dude

SLC Duster Dude

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I'm swapping the cam, intake, and heads on my 360 LA. (74-79) The damper that was on it is this:
Professional Products PowerForce Plus Harmonic Dampers 90012

And I'm replacing it with this:
Trick Flow® Track Max® Harmonic Dampers TFS-19011

My question is the weight on each is a different size. Also, they both say they are for 360 but one is 7.25" and the other is 7.010".

What am I missing?

rFahb5BTRfyRgKJYIB9Y3w.jpg


TFS-19011.jpg
 
My quest would be the weight difference is due to the different diameter dampers.
 
If I'm reading this correctly it's not a weight difference it's a diameter difference being the outside circumference is just a Skippy little bit bigger than the other which probably won't matter one bit.
 

Also I wouldn't think the amount of weight would make the difference. It would be more in the amount of offset weight that would make the difference.
SLC Duster Dude said:
The first one has all the timing marks worn off and I wanted something easier to read.
Click to expand...
Lol, so the possibility of you cleaning it real well spray painting it nice black again and taking a white marker and drawing lines back on there is beyond? I know some people like just brand new stuff and everything cleaning new so that could be just a preference. If you're ever looking to get rid of that old harmonic balancer LOL
 
SLC Duster Dude said:
I'm swapping the cam, intake, and heads on my 360 LA. (74-79) The damper that was on it is this:
Professional Products PowerForce Plus Harmonic Dampers 90012

And I'm replacing it with this:
Trick Flow® Track Max® Harmonic Dampers TFS-19011

My question is the weight on each is a different size. Also, they both say they are for 360 but one is 7.25" and the other is 7.010".

What am I missing?

View attachment 1715126500

View attachment 1715126501
Click to expand...
Those balancers (with no weights mounted) will weigh a certain number. Some are heavier than others. The required weight to use for your motor for each balancer will weigh a certain number. Divide that removable weight number by the balancer number and you get a percentage. I doubt many of the balancers available with removable weights will give the same percentages but they will be close by a few grams/ozs as I recall when looking for one myself. Edit, gotta correct what I stated here after rereading. I confused the question at hand with the few balancers that supply the various weights for a 340 crank, a 360LA, and the Magnum and how much each balancer, and the weight weighs. So nevermind!
 
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The position of the weight makes a difference. If you look, both weights appear to be a different distance from the key way.

If the crank was balanced with the original damper (and it should have been) you can change the balance and induce a shake.
 
the trick flow weight looks thicker? so it can be shorter in length and weigh the same as the other. I like the one with 2 bolts holding the weight on better than only 1 bolt
 
Guys, guys, guys .... the external balance damper needs a certain amount of what is called 'moment'. Moment is determined by:
1. taking the exact distance from the center of the weight to the center of the crank snout
2. the exact amount of the weight
3. multiply the 2 together to get a moment, typically specified in in-oz

So a 10 oz weight at 2" from the crank center will have the same moment as 5 oz at 4". Both will be 20 in-oz of moment and both will provide the same external imbalance to the engine.

Sorry to say this but post #9 is not correct. There is no set relationship between the amount of the damper's weight and the weight of imbalance; the 2 numbers are totally independent of each other. The damper without the weight can weigh 1 oz or 100 lbs; regardless of the damper's overall weight, the same imbalance weight attached to either one at the same distance from crank center will create the exact same moment.

The moment also has to be at a certain angle to the crank key. OP, what bothers me with the pix you show is that the angles between the crank keyways and the center of the weights is quite different between the 2. That is a problem. However, the top pix shows a small recess machined inside the hub that extends under the bolt-on weight. As best I can tell, that effectively makes the angle difference a tad worse but we can't really see it. BUT it may well be that the 2nd pix is a stock photo, and does not really represent the 360 damper; I am guessing that is what is going on.

So if you get the new 360 damper, compare the angle between the keyway and the center of the weight to the old one to see if they are pretty close.

For me, if the old damper is pretty good, then I'd put on a timing tape as suggested.
 
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