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Re: Convertible Corner Weights
Posted by: joelsplace ()
Date: November 02, 2019 11:47AM

They are not pneumatic dampers. You can fill them up. They might need a tiny bit of air to account for temperature changes.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Convertible Corner Weights
Posted by: Timothy Shortle ()
Date: November 02, 2019 01:32PM

I thought ATF was used in them. I looked in the 65 shop manual and did not find any suggested servicing of these.

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Re: Convertible Corner Weights
Posted by: American Mel ()
Date: November 02, 2019 07:06PM

Timothy Shortle Wrote:
-------------------------------------------------------
> I thought ATF was used in them. I looked in the 65 shop manual and did not find any suggested servicing of these.


What I was saying earlier.
I can not for the life of me understand why anyone would feel that they needed to open one up at all, let alone "Change the Oil" ! ? ! ? ! ? confused smiley
Unless they were shipping it across the country, and thought it would be cheaper if it weighed less?
But again, I ask, wouldn't changing the viscosity of the oil change the damping characteristics?
If you do not know what the factory oil is, I would not advise changing the oil.

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza - Sale pending
Have had; '61 Monza coupe, '62 Monza Wagon, '63 Spyder, '65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dualy, approaching 400K
17'Terry

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Re: Convertible Corner Weights
Posted by: ral1963 ()
Date: November 02, 2019 07:52PM

I wouldn't think you would ever need to change the fluid just for changing it.

However if one in storage leaked, you would want to add fluid back to it.

I don't think they are tuned to a specific harmonic, I think they are just designed to absorb energy that would ultimately be transferred to the body.

I think the fluid just provides resistance to the movement of the weight, it is the weight itself that is doing the damping, so as long as there was "something" in there to do the job, it would be better than nothing.

Rick Loving
Corvair historian & chronicler of useless facts
CORSA
Performance Corvair Group
Chicagoland Corvair Enthusiasts

RAL1963@COMCAST.NET
Just south of Chicago IL

Current Ride
63 Sprint Vert 140/4sp

Past Rides
60 700 Sedan 80hp PG
63 Monza Vert 102hp 4 spd
63 Monza Coupe 140hp 4 spd
63 700 Sedan 80hp 3 spd
64 Monza Vert 110hp 4 spd
64 Monza Coupe 95hp 3 spd
64 Monza Sedan 110hp PG
65 500 Coupe 95hp 4 spd
65 Monza Coupe 110hp PG
65 Corsa Coupe 140hp 4 spd
66 Turbo Coupe 180/4sp
68 Monza Vert 140hp 3 spd

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Re: Convertible Corner Weights
Posted by: American Mel ()
Date: November 02, 2019 07:56PM

I can live with that answer. smiling bouncing smiley

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
Have; '66 Monza Coupe - 140, 4-spd. Daily driver beater
'67 Monza Vert. - 140, 4-spd. Daily driver beater
'67 A/C Moredoor Monza - Sale pending
Have had; '61 Monza coupe, '62 Monza Wagon, '63 Spyder, '65 Corsa
.
non-vair
'04 Dodge Cummins Quad Dualy, approaching 400K
17'Terry

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Re: Convertible Corner Weights
Posted by: JerryM ()
Date: November 02, 2019 08:43PM

Olley describes the device in "Chassis Design Principles and Analysis"
He(refers to Hertogs tuned mass dampers)explains the damping for the bob-weight is determined by the amount of air trapped in the shell. The oscillations he's illustrating are of the sprung/unsprung mass and the resonance of the pnuematic tire. He also talks about the dampers (shocks) effect on this. The take-away for me is the volume of oil would be more significant than viscosity and these were "tuned" for the tire and shock absorber technology of the day which may explain why very little change is felt with or without them.

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Re: Convertible Corner Weights
Posted by: FLSteve ()
Date: November 03, 2019 04:13AM

Does anyone have pictures of one of these open up?

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Re: Convertible Corner Weights
Posted by: Wagon Master ()
Date: November 03, 2019 06:41AM

This is the best I could do. Max flash. High resolution. Macro.



Edited 1 time(s). Last edit at 11/03/2019 06:42AM by Wagon Master.

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Re: Convertible Corner Weights
Posted by: NMCarNut ()
Date: November 03, 2019 08:48AM

Excellent article on the shakers including a cutaway picture in the April 2018 Lehigh Valley Corvair Club newsletter:

[www.corvair.org]

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Re: Convertible Corner Weights
Posted by: ral1963 ()
Date: November 03, 2019 09:15AM

Thanks, I knew I saw that pic somewhere but couldn't find it.

Now we need someone who has a stock one that appears to never have leaked, to open it up and see if it is full or how much volume of oil is missing.

Then drain a drop out and see if it is oil or ATF...

I don't have any in my parts stash or I would.

Rick Loving
Corvair historian & chronicler of useless facts
CORSA
Performance Corvair Group
Chicagoland Corvair Enthusiasts

RAL1963@COMCAST.NET
Just south of Chicago IL

Current Ride
63 Sprint Vert 140/4sp

Past Rides
60 700 Sedan 80hp PG
63 Monza Vert 102hp 4 spd
63 Monza Coupe 140hp 4 spd
63 700 Sedan 80hp 3 spd
64 Monza Vert 110hp 4 spd
64 Monza Coupe 95hp 3 spd
64 Monza Sedan 110hp PG
65 500 Coupe 95hp 4 spd
65 Monza Coupe 110hp PG
65 Corsa Coupe 140hp 4 spd
66 Turbo Coupe 180/4sp
68 Monza Vert 140hp 3 spd

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Re: Convertible Corner Weights
Posted by: Lane66m ()
Date: November 03, 2019 09:27AM

I have 7 of those that you are looking for. But don't plan to open any as they are available for sale. I can weigh them for you if that helps.

Al Lane
Ellabell, GA 31308

1966 Monza Coupe, 110 hp, 4 Spd
1966 Monza More Door 110 hp, PG
1968 Camaro SS Coupe 350 CI 295+ hp PG
1964 Greenbrier Deluxe, 6 dr, 80 hp car engine, PG
1947 Farmall A tractor 15 hp


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Re: Convertible Corner Weights
Posted by: Phil Dally ()
Date: November 03, 2019 09:28AM

In fact they do have some moving parts.

Changing fluid after 50+ years...good idea.

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Re: Convertible Corner Weights
Posted by: The Stig ()
Date: November 03, 2019 09:44AM

Well crud I went out to open the ones in my EO vert. I didn't recall how high they mount in the trunk and you cant remove the plug with them in place. Then I realized they are missing in the back! Now I will have to find some again.

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Re: Convertible Corner Weights
Posted by: ral1963 ()
Date: November 03, 2019 09:45AM

Al, how much for one? without shipping...

Rick Loving
Corvair historian & chronicler of useless facts
CORSA
Performance Corvair Group
Chicagoland Corvair Enthusiasts

RAL1963@COMCAST.NET
Just south of Chicago IL

Current Ride
63 Sprint Vert 140/4sp

Past Rides
60 700 Sedan 80hp PG
63 Monza Vert 102hp 4 spd
63 Monza Coupe 140hp 4 spd
63 700 Sedan 80hp 3 spd
64 Monza Vert 110hp 4 spd
64 Monza Coupe 95hp 3 spd
64 Monza Sedan 110hp PG
65 500 Coupe 95hp 4 spd
65 Monza Coupe 110hp PG
65 Corsa Coupe 140hp 4 spd
66 Turbo Coupe 180/4sp
68 Monza Vert 140hp 3 spd



Edited 1 time(s). Last edit at 11/03/2019 09:47AM by ral1963.

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Re: Convertible Corner Weights
Date: November 03, 2019 10:19AM

Camaro guys say it is ATF:
chevy-camaro.com/faq/chevy-camaro-convertible-cocktail-shakers


Dan Davis ~ Pierce County, WA ~ CORSA Western Director + Corvairs NW + North Cascades Corvairs + Corvanatics
1966 Corsa Turbo coupe ~ ~ 1966 Corsa 140 Coupe ~ ~ 1965 Monza 140/4 Convertible Sierra Tan/Fawn ~ 1964 Monza Spyder Convertible ~ 1960 Monza Ermine White/Red PG ++ ~ 1965 Monza 140/4 CoupeEvening Orchid w/ ivory/black interior ~ 1962 Monza Wagon 102/4 ~ 1963 Rampside/Scamper ~ 1963 Red/Greenbrier ~ 1969 Ultra Van #468

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Re: Convertible Corner Weights
Posted by: ral1963 ()
Date: November 03, 2019 10:43AM

In regards to the statement that the dampers are tuned...

I can't accept that the tuning is specific..unless it was a broad range.

Everything would affect it, how many passengers, how much fuel and/or cargo you were carrying, and that is only on a brand new car.

Add a little age and rusting of the rockers and floors where the metal is not a strong as a brand new car completely different.



….for future searches if the link ever goes bad...

from Q&A at link in above post…

On the corners of convertibles there are what's called "cocktail shakers" or vibration dampeners which were originally installed on every first gen convertible Camaro to help prevent vibrations. They were installed due to a very flexible body in the convertible models because of the lack of the roof structure. Some reinforcement was added to the convertible rockers and floors but it wasn't enough to prevent all vibration problems. The cocktail shakers are large cans with a suspended mass on a spring in a viscous fluid that are mounted on the corners - 4 in all. They were tuned to a resonant frequency of the convertible that caused the vibration problems. When the body was subjected to loading that would otherwise tend to make it oscillate, much of the energy was instead absorbed by the motion of the masses in the cocktail shakers - which reduced the vibration in the convertible body. The cocktail shakers weight about 25 pounds each.

It certainly would be possible to add a large amount of structural stiffness(subframe connectors won't be anywhere near enough) to the mid-section of the body to reduce or eliminate the vibration to the point of being able to remove the cocktail shakers. However that possibility would be very remote without a complete understanding of the Camaros stress and flex points. Another option would be to design and build your own vibration dampener. That, however, would require knowledge of the structural frequencies of the Camaro convertible body not to mention knowledge of how to tune the damper you are creating. The cocktail shakers are filled with automatic transmission fluid or ATF. The fluid is not subjected to friction, high heat or contamination as is the case with other fluid applications in the vehicle so it should not "wear out". The springs would be the only thing that could change or break, that would keep them from working properly. We have never found a "bad" one, if it still has fluid in it, only cars missing them which have the common' cowl shake' much worse than normal. If your convertible Camaro has all four cocktail shakers and you still have bad vibration problems be sure to check that your tires are balanced properly and also new OEM body bushings can help reduce some of the vibration transfer. Be sure to check your springs and shocks as well. You should also try adding subframe connectors to help with flex and vibrations

If your original cocktail shakers are missing you would be better off trying to find an original set to replace them.

Rick Loving
Corvair historian & chronicler of useless facts
CORSA
Performance Corvair Group
Chicagoland Corvair Enthusiasts

RAL1963@COMCAST.NET
Just south of Chicago IL

Current Ride
63 Sprint Vert 140/4sp

Past Rides
60 700 Sedan 80hp PG
63 Monza Vert 102hp 4 spd
63 Monza Coupe 140hp 4 spd
63 700 Sedan 80hp 3 spd
64 Monza Vert 110hp 4 spd
64 Monza Coupe 95hp 3 spd
64 Monza Sedan 110hp PG
65 500 Coupe 95hp 4 spd
65 Monza Coupe 110hp PG
65 Corsa Coupe 140hp 4 spd
66 Turbo Coupe 180/4sp
68 Monza Vert 140hp 3 spd

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Re: Convertible Corner Weights
Posted by: flat_six ()
Date: November 03, 2019 01:41PM

Interesting discussion. As someone who is relatively new to the convertible scene (66 Corsa bought 2 years ago), I was always under the impression that the cocktail shakers were filled with buckshot and oil. The spring mass system in the photos here makes a lot more sense!

One clarification that needs to be made: the chassis stiffness (or flex depending on how you approach it) that we are discussing here is torsional rigidity. The article above that uses the ruler on the table analogy is incorrect, as it views the chassis rigidity issue in convertibles as a beam bending problem (think diving board).

So "cowl shake" as perceived by the driver is really the front of the car twisting back and forth relative to the rear of the car. Using the ruler analogy, you would hold one end flat on the table, and twist the other.

Both bending and torsional stiffness is reduced when you remove a roof from a chassis. However, the bending stiffness is more easily addressed through added
structure, and remains relatively high compared to torsional rigidity.

Torsional rigidity is defined in terms of critical frequency (Hz), or also torsional displacement/degrees per ft-lb moment applied. When stiffness is increased, the critical frequency (first harmonic) of the structure goes up.

The torsional critical frequency in our verts is much lower than the coupes, thus the massive springs and weights. Yes, this is a band-aid, but must have been the best overall solution given the chassis design and technology at the time. I am curious as to why the earlies did not seem to need them.

The cocktail shakers of course do nothing to change the torsional rigidity of the chassis, but are in fact tuned resonate at the most noticeable (ie. annoying to the driver) torsional frequency, thus countering the motion of the body and providing a vibration free ride.

As an educated guess, the biggest variables here are potentially: body torsional rigidity becoming lower over time due to fatigue/corrosion, and perhaps the frequency of the dampers changing due to oil breakdown, fatigued springs, or broken parts.

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Re: Convertible Corner Weights
Posted by: MattNall ()
Date: November 03, 2019 01:49PM

flat_six Wrote:
-------------------------------------------------------
> I am curious as to why the earlies did not seem to need them.

=================================================================

Early's were designed to be stiffer... and they have way more spot welds than Lates.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Convertible Corner Weights
Posted by: joelsplace ()
Date: November 03, 2019 04:23PM

EMs are better than LMs. Everyone should know that.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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Re: Convertible Corner Weights
Posted by: JerryM ()
Date: November 03, 2019 05:19PM

Since the engine is not rigidly mounted to the the chassis, it would inherently work as a mass balancer as well. Maybe some of the difference between early and late are related to the difference in mounting the drive train.

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