Lycoming flywheel balance weight limit?

As the title suggests, does anyone know if there is a limit to how much weight you can add on a Lycoming flywheel? I can't find any documentation from Lycoming.

In the pic I ended up with 51 grams. Anyone see any problems with this? I didn't have any AN970 washers somehow so this is what ended up working. Got her down from .47 to to .01 IPS

Thanks in advance!

Can't say I've ever seen so many weights installed at different locations like that.
98% of the time I use just 2 locations (one location is rare), offhand probably around 25 grams at each spot would be close to what I might use on a high vib prop/assy (.47 is pretty high). I don't think what I see there would be a problem, except if I saw that I would probably think the operator didn't have a good grasp of the process, or in your case didn't have the proper hardware.
With that many weights it also turns into a hit or miss operation, I imagine you had to run it quite a few times guessing where to put weights?

Walt said:

Can't say I've ever seen so many weights installed at different locations like that.
98% of the time I use just 2 locations (one location is rare), offhand probably around 25 grams at each spot would be close to what I might use on a high vib prop/assy (.47 is pretty high). I don't think what I see there would be a problem, except if I saw that I would probably think the operator didn't have a good grasp of the process, or in your case didn't have the proper hardware.
With that many weights it also turns into a hit or miss operation, I imagine you had to run it quite a few times guessing where to put weights?

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Walt thanks for the reply. I should have clarified some stuff in my first post. I always understood what the Dynavibe was telling me but weights were my issue.

It certainly doesn’t look as good as I would like and I will at a later date move to a 2 bolt split but I simply had no other way of adding weight but to move to the next holes adjacent the target. I did it in four runs including the initial. After the first run with weight added I realized I was going to have to use quite a bit more as it only went from .47 to .35. This resulted in 2 more bolts with max weight I could get on them. This brought it to .12 and I thought I could do a little better with the last weight, which nailed it.

Long story short, AN970s are on order to move to a 2 bolt split. I could not believe I didn’t have any in the hangar! Just wanted to make sure the temporary weight setup wasn’t in Lycoming no-no land somehow. Haha

I do appreciate your response, was really hoping to hear from you since I know you are quite versed in this area.

The first time I had my prop balanced the weight was higher than he liked. He had me reinstall the prop 180 from before and it took less weight. I dont remember what the total was.

Apparently I’m not the only one that has had a 4 weight setup initially. In this Kitplanes article Dave does the math to turn a 4 location weight into a 2 location weight. Hope this helps any future readers.

https://www.kitplanes.com/propeller-balancing/

can't imagine weight is an issue, as they sometimes put heavy electric or fluid deicing devices on that ring. That is why Lyc puts the 12 holes in it.

I never heard of limit, but what you have looks fine. In my balance kit I have a variety of hardware of all different materials and weights to be able to customize the weight to be exactly what I want. If you confine yourself to AN hardware you are limiting your weight options. - Those nuts could be replaces with much heavier nuts (Mcmaster Extreme Strength Nuts). You can also use stick-on lead tape that is not going to come off and lets you put the weight exactly where needed so you don’t have to split the weight.

pa38112 said:

You can also use stick-on lead tape that is not going to come off and lets you put the weight exactly where needed so you don’t have to split the weight.

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It's not gonna be pretty when it comes flying off
Everybody stand back!

Walt said:

It's not gonna be pretty when it comes flying off
Everybody stand back!

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Some people don't understand how much centrifugal force there can be at 2700 rpm. The forces on car wheels tend to press the weights more tightly onto the wheel. Not so on a flywheel.

There IS a limit. And it's very clear in the instructions. The first reading has a limit of 1.2 IPS..... If it is over, remove the prop and balance it. Or as mentioned above, try it mounting at 180*.

1.5 oz mounted at that point from the center of the hub is up around 80#(guess) at 2700 rpm. IOW, don't use stick on weights.... also noted in the instructions.

lr172 said:

can't imagine weight is an issue, as they sometimes put heavy electric or fluid deicing devices on that ring. That is why Lyc puts the 12 holes in it.

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Oh cool, had no idea that's where that stuff was often mounted.

gasman said:

There IS a limit. And it's very clear in the instructions. The first reading has a limit of 1.2 IPS..... If it is over, remove the prop and balance it. Or as mentioned above, try it mounting at 180*.

1.5 oz mounted at that point from the center of the hub is up around 80#(guess) at 2700 rpm. IOW, don't use stick on weights.... also noted in the instructions.

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While true 1.2 IPS is the limit I thought I read somewhere in one of the manuals that was a limitation of the balancing equipment. Not positive on that though. It does make sense to pull a prop and static balance if you pulled an IPS that high though!