1929 Chrysler - engine vibration absorber

[JRA]

Hello Folks,

Sometime ago I was able to buy a part was missing under the hood of my 1929 Chrysler model 75. It is a sort of "engine vibration absorber". It is an steel arm attached to a bumper at the firewall, this arm connects to a regular bolt in the engine head.

I have now decided to install it, but I would like to understand how it works, why Chrysler developed such system, if there is any special actions I should take to install the part, and if it is really useful. Any ideas?

In my perception the level of vibration of the engine seems to be normal. After I installed thick rubber engine mounts, it became better. When I bought car, the engine mounts were missing.

The picture below shows the setting in a car I found on the internet. I rounded it in red, it is under the brake fluid canister. 

Thanks, JRA

[hwellens]

It bolts to the head stud. Should help to dampen the vibrations from the motor transferring to the car body

[JRA]

Was this system used in other cars at that time or in other periods? 

[F&J]

6 minutes ago, JRA said:

Was this system used in other cars at that time or in other periods? 

Early Plymouth 4 in at least 1929 had the identical unit mounted in the same place, but I found it interesting that the 29 Desoto 6 never had these.

 

I do know that the 29 Plymouth 4 that I had did have it's share of engine vibrations, and the 29 DeSoto 6 that I owned, had less engine vibration,  

 

I just never understood that system.  It seems it would transfer more vibration to the body?  IDK.

Edited July 30, 2020 by F&J (see edit history)

[broker-len]

Plymouth 4 cylinder,,,PA,,,, has a lief spring from frame to transmission to control the vibration of the motor because of the FLOATING POWER feature          not familiar with your car but it seems the part in question  would make vibration worse

[FLYER15015]

So, what's in the box ?

Does it work like a friction shock ?

If so, Is the tension adjustable ?

I don't have anything like that on my '31 CG.

And I don't see any provision on the firewall to accommodate one.

 

 

Mike in Colorado

[broker-len]

It seems the goal of vibration control is to isolate the motor from body     it seems that arm is directly linking the motor with body   make vibration worse          what am I missing !!!!!

[Rusty_OToole]

I'm guessing that the Floating Power flexible motor mounts allowed too much rocking or side to side movement of the engine so they added a stabilizer link  to steady it, and put a rubber mount at the body end to damp out vibration and noise transfer to the body.

Edited July 31, 2020 by Rusty_OToole (see edit history)

[viv w]

The Chrysler models 50 and 52 had these dampers fitted and they did not have floating power mountings.

  One wonders if this part is to stop motor vibration, to steady the motor from rocking or perhaps to limit scuttle/cowl shake on rough roads.

[F&J]

9 hours ago, FLYER15015 said:

Does it work like a friction shock ?

yes, exactly like that.

 

9 hours ago, FLYER15015 said:

If so, Is the tension adjustable ?

no

[JRA]

Should the firewall unit be installed directly to the metal or should I use some rubber washings or gasket?

[FLYER15015]

3 hours ago, JRA said:

Should the firewall unit be installed directly to the metal or should I use some rubber washings or gasket?

I would think that  the "box" has to be mounted solidly to the firewall, for the shock mechanism to do the work.

That's what it looks like in the picture above.

I wonder how they calculated the amount of "resistance" that was required, and how it was set.

 

Also per the picture above, I see that the engine is a "red head".

Is this feature specific to red head engines ?

My '31 CG is also a red head, and maybe by '31 they got the front dampener right, or it was not needed on the straight 8's.

The Chrysler historian needs to jump in here.

 

Mike in Colorado

 

Edited July 31, 2020 by FLYER15015 (see edit history)

[F&J]

1 hour ago, FLYER15015 said:

Is this feature specific to red head engines ?

No, my 29 Ply had the standard head, and I'm not even sure the Ply had a red head option.

[JRA]

My Chrysler 75 does not have red engine head, but based on holes and marks on the firewall, it is clear it had the part installed there in the past, that’s the reason I bought the damper.

Edited July 31, 2020 by JRA (see edit history)

[28 Chrysler]

It is used to dampen the torque movement of the engine as far as I know. They are non adjustable and not red head specific.

[viv w]

They are bolted directly onto the firewall with no gasket or rubber. as far as I know they are not adjustable

 

[FLYER15015]

I still would like to know what is in the box.

A sliding blade, or a block of rubber ?

 

Mike in Colorado

[Vintageben]

Yeah here is a couple of pictures of the one on my Chrysler 75 project. Bolted straight to the firewall and the head. My Chrysler 65 has the same set up 

[28 Chrysler]

19 hours ago, FLYER15015 said:

I still would like to know what is in the box.

A sliding blade, or a block of rubber ?

 

Mike in Colorado

That is about it, a sliding blade hooked to a block of rubber.

[FLYER15015]

So, if the engine block is secured to the frame rails down below the starter,

and the crank case vent tube on the other side,

then this gizmo is apparently meant to minimize "head shake" ?

 

Mike in Colorado

[Flivverking]

I don't think this gizmo is any type of vibration damper as these engines are pretty well balanced. It (is) more of a stablizer thing to reduce the twisting torque effect of the engine being solidly mounted very low and the tall block having then a high center of gravity thus reducing strain on it's mounts.

Just an arm chair pitch..

Take one off and realy  hammer  on the gas and see if the clutch .brake pedal and shifter rock under excelleration.😨

[hwellens]

Here is the answer from a Chrysler brochure: