Spring Mounted engine mounts for Model A

Sheldon Paulger

Junior Member
I have a Float a motor kit installed in the rear engine mounts of my 1930 Coupe.

The rubber donuts are very stiff, in my mind not giving much vibration absorption. Has anyone tried replacing the rubber donuts with springs?

Thks
Sheldon
 
I don't believe they make a spring for that style. I use all stock.
 

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I replaced F-O-M's on my tudor with stock mounts, and could tell no difference in any vibrations, but it helped clutch chatter as it made the whole chassis more rigid.
 
If you are so inclined, you can select springs from a company such as Century Spring (or similar spring manufacturers). From their stock, they can come very close to matching just about any spring dimension/material that you can come up with.
https://www.centuryspring.com/?gcli...2ezIsLDgwUnaMocKLGOpezT-v9VhtsWUaAkEAEALw_wcB

The caveat is they have a minimum quantity requirement, or is it a minimum dollar requirement? Its been a long time. Anyway, you get the idea.

They will custom make springs for you also, if you have deep pockets.

If I'm not mistaken, McMaster-Carr will custom make springs also. Also not so cheap...50 USD for the first one I think. Its been about 15 years since I did that stuff, so my errors may abound!

To properly select a spring, Science stuff and Engineering voodoo are needed. Please use your brain or someone else's brain to do it right! If you were copying a spring it would be much easier than replacing a rubber pad with a spring.
 
I replaced F-O-M's on my tudor with stock mounts, and could tell no difference in any vibrations, but it helped clutch chatter as it made the whole chassis more rigid.

I found you have to use all the floatamotor mounts,front,rear and transmission.I tried with with the Ford stock 'wishbone' front mount and floatamotors on the rear,she shivered like a dog passing peach pits
 
I replaced F-O-M's on my tudor with stock mounts, and could tell no difference in any vibrations, but it helped clutch chatter as it made the whole chassis more rigid.

The original solid engine mounts form what amounts to another cross member. By the time they and the flywheel housing are all bolted up tight, they take a lot of flex out of the chassis.
IMO, this is why flywheel housings crack so readily.
 
The original solid engine mounts form what amounts to another cross member. By the time they and the flywheel housing are all bolted up tight, they take a lot of flex out of the chassis.
IMO, this is why flywheel housings crack so readily.


Just want to clarify, you're saying that the housings crack more readily with the stock mounts or the FAMs?


FWIW, I converted to FAMs earlier this year and retained the stock front mount. The vibration reduction was noticeable and clutch chatter is not an issue. I used the transmission mount that was included.



There is a great write up from MikeK somewhere explaining how the vibrations of even a mildly hopped up engine, like mine with a 5.5 head and reground cam, produce a ton more vibration than the stock engine and that the FAMs really do help to alleviate that BUT the rubbers need to be soft for them to do the job.
 
Sheldon, I dont think a spring will work as I manufactured springs for 30 years . First it would have to be a conical spring that can support itself with a side load as well as the force of the motor. Now can it be done sure but lots would have to make a number of them to see what works best. A combination of both rubber and spring would be better .
It’s funny as you can buy donut motor mounts from most suppliers but they all seem to be different . I would try a different supplier for softer rubber as said by others.
 
Just want to clarify, you're saying that the housings crack more readily with the stock mounts or the FAMs?


FWIW, I converted to FAMs earlier this year and retained the stock front mount. The vibration reduction was noticeable and clutch chatter is not an issue. I used the transmission mount that was included.



There is a great write up from MikeK somewhere explaining how the vibrations of even a mildly hopped up engine, like mine with a 5.5 head and reground cam, produce a ton more vibration than the stock engine and that the FAMs really do help to alleviate that BUT the rubbers need to be soft for them to do the job.

It is my belief that the solid mounts will cause the flywheel housing to crack earlier than with soft mounts.
I have done more to my engine than you have and like you say, vibration is greatly reduced. I didn't use the mount on the cross member and I can induce a slight shudder in reverse but it is not a problem with ordinary driving. I have used the original spring type front mount.
 
Sheldon I think the spring idea is taking you down the wrong road. This road will be nothing but problems.

And Jack, you have a way with words. "she shivered like a dog passing peach pits" OUCH!!!!

Ya well, maybe she shivered like a dog passing coconuts. So there!
 
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