The Ford Barn

oldbike99 · 02-09-2015, 10:34 AM

Since the radius rod connects to the clutch housing, does the use of a "float-a-motor" kit noticeably affect the handling of a Model A?
Thank you in advance

Charles Coe · 02-09-2015, 10:44 AM

My dad's Tudor has float-a-motor mounts and I can't tell any difference in the handling.

MrBruce · 02-09-2015, 11:50 AM

Not that I can tell. I've run them for years.

BILL WILLIAMSON · 02-09-2015, 02:12 PM

"FLOAT" was a poor choice of a word for these mounts! NOTHING FLOATS, they just insulate motor/power train noises from getting into the chassis & body & making conversation difficult & your body NUMB!
Bill W.

Synchro909 · 02-10-2015, 07:55 AM

Quote:

Originally Posted by oldbike99

Since the radius rod connects to the clutch housing, does the use of a "float-a-motor" kit noticeably affect the handling of a Model A?
Thank you in advance

Does the use of Flot a Mota mounts allow the chassis to spread at the engine mounts? Has anybody heard of this? One of my cars with these mounts started to develop cracks in the firewall where the steering column goes through it and I wondered whether the mounts might have allowed the chassis rails to spread.

George Miller · 02-10-2015, 09:10 AM

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Not sure about spread. But they will allow the rails to twist.

fins2nv · 02-10-2015, 09:21 AM

I put the float-a-motor kit in my '30 coupe. It didn't affect the handling, but it got rid of a very annoying vibration and made the car much more enjoyable to drive.

Will N · 02-10-2015, 10:58 AM

Here we go with the FAM debate again! There are supporters and detractors, and you're going to get lots of opinions. My opinion is that the original rear motor mounts act as a fourth frame crossmember, tying the frame together at a point where it is bearing a lot of weight. The FAM setup does not do so. FAMs really should not impact handling, especially if that rear clamp that ties the transmission to the center crossmember is in place, limiting front to rear movement of the engine to the degree that the rubber isolator can flex.

oldbike99 · 02-10-2015, 11:13 AM

Thank you for your reply. I was not aware that the float a motor setup linked the transmission to the crossmember. This answers my question

BILL WILLIAMSON · 02-10-2015, 02:30 PM

Quote:

Originally Posted by oldbike99

Thank you for your reply. I was not aware that the float a motor setup linked the transmission to the crossmember. This answers my question

NO, it's NOT linked!! It's just there to prevent a "possible" THUNK! Many of our guys don't even bother to install them. Do whatever you WANT to do, Fido & I really don't care.
Minerva was wonderful with them! I'm too tired to put them on Vermin.
Bill W.

garyaodell · 02-11-2015, 01:09 AM

When I got my 29 coupe it had rear FAMs, I have driven the car this way for five years. The tabs on the pans that go between the engine and frame have broken off and I have had to repair cracks in the radiator inlet nozzle, I believe this caused by movement between the frame and the engine allowed by the FAM. I just replaced the FAM with the original motor mounts and new rubber pads and my first impression is the car feels much more solid and I noticed no increase in vibration. I can't see that the FAM made any improvement over the original mounts.

oldbike99 · 02-11-2015, 09:13 AM

I have decided that since the original design has worked for 80 years, I will refurbish it with new rubber and let it go for another 80 years. Thanks for everyone input. I appreciate it.

RockHillWill · 02-11-2015, 10:24 AM

The FAM debate is always interesting to follow because of the varied 'opinions'. I am 73 years old and have never encountered an opinion that altered the laws of physics. I am reasonably familiar with chassis considerations and offer the following points.

Any bump encountered feeds the load into the chassis. Because the Model A axles are solid and share one spring at each end the load can often be multiplied. Original shocks offer little way in dampening these loads.

This load will apply itself mainly to only one corner of the car imparting a twisting load on the chassis. The greatest flex will occur at the weakest point along the chassis. If you look at the side of the Model A frame, you will see that the deepest section of the frame starts in front of the rear motor mount section and extends beyond the middle steel cross member. When the original motor mounts are in place it forms a 'boxed' portion of the chassis offering further isolation of load input along the chassis and isolating front suspension load input from rear suspension input. Also note that the bolt pattern for the rear motor mount plates is vertical as well as horizontal indicating a need to resist twist in that area. Also consider what the use is for the steel sleeves in that vertical section of the rear motor mounts.

If the original rear motor mounts are not used there is noticeable less flex resistance in that vicinity where both the firewall and the door hinges are located. I have noted multiple cracks in firewalls at the lower corners, even with original mounts. Consider what happens to the doors ability to remain latched if the front door hinges are allowed to move vertically with additional chassis flex. Drooping chassis make this an even more area for concern.

Often overlooked in this discussion is the concern for fore and aft movement when using FAM's. The fore and aft movement of the ENTIRE drivetrain is controlled by the rigidity of the rear motor mounts. The rear end transmits both accelerating and braking loads to the chassis thru the two trailing arms. They are attached to the torque tube that is attached to the transmission that is attached to the bell housing that is attached to the flywheel housing that transmits the load to the chassis when you either accelerate or brake. The same situation occurs at the front axle thru the wishbone thru the bell housing, etc. With FAM's, the entire fore and aft loading is controlled by the front motor mount (one small VERTICAL bolt) and the durometer measurement of those FAM's. This might seem of little concern if you are a VERY smooth and cordial driver and never encounter an emergency situation.

What might be the result if you backed up at only 5 MPH and hit a curb with one or both rear wheels? The body would tend to continue rearward, but that solid rear axle with stop in place, making the T/A, trans, hsg's, motor and WATER PUMP stop in place as well. The radiator is now part of the components that is still moving rearward. If you have more than an inch between the radiator and the water pump you might be OK, otherwise there is a significant risk of puncturing the rear face of the radiator.

Again this is merely a benign offering for your consideration. Personally, I feel that if you own a Model A, you should be able to do whatever you want to do with it to be able to have fun and enjoy it.

MrBruce · 02-11-2015, 11:55 AM

Some good points Will, I started the FAM early on before we started to balance the engines. I think I might try going back on my new touring motor and see how it runs. It is an important link when hooked up and bolted to the rear of the engine like it is. Food for thought, thanks for the input.

02-09-2015, 10:34 AM	#1
oldbike99 Senior Member Join Date: Oct 2012 Location: Grand Forks, ND Posts: 195	Handling/Suspension question Since the radius rod connects to the clutch housing, does the use of a "float-a-motor" kit noticeably affect the handling of a Model A? Thank you in advance

02-09-2015, 10:44 AM	#2
Charles Coe Senior Member Join Date: May 2010 Location: Pace, FL near Pensacola Posts: 374	Re: Handling/Suspension question My dad's Tudor has float-a-motor mounts and I can't tell any difference in the handling.

02-09-2015, 11:50 AM	#3
MrBruce Senior Member Join Date: Oct 2014 Location: Charlotte, NC Posts: 327	Re: Handling/Suspension question Not that I can tell. I've run them for years.

02-09-2015, 02:12 PM	#4
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: Handling/Suspension question "FLOAT" was a poor choice of a word for these mounts! NOTHING FLOATS, they just insulate motor/power train noises from getting into the chassis & body & making conversation difficult & your body NUMB! Bill W. __________________ "THE ASSISTANT GURU OF STUFF"

02-10-2015, 09:10 AM	#6
George Miller Senior Member Join Date: May 2010 Location: NC Posts: 2,975	Re: Handling/Suspension question Sponsored Links (Register now to hide all advertisements) Not sure about spread. But they will allow the rails to twist.

02-10-2015, 09:21 AM	#7
fins2nv Member Join Date: Aug 2014 Location: Fargo, ND Posts: 73	Re: Handling/Suspension question I put the float-a-motor kit in my '30 coupe. It didn't affect the handling, but it got rid of a very annoying vibration and made the car much more enjoyable to drive.

02-10-2015, 10:58 AM	#8
Will N Senior Member Join Date: Jul 2010 Location: Pennsylvania Posts: 1,250	Re: Handling/Suspension question Here we go with the FAM debate again! There are supporters and detractors, and you're going to get lots of opinions. My opinion is that the original rear motor mounts act as a fourth frame crossmember, tying the frame together at a point where it is bearing a lot of weight. The FAM setup does not do so. FAMs really should not impact handling, especially if that rear clamp that ties the transmission to the center crossmember is in place, limiting front to rear movement of the engine to the degree that the rubber isolator can flex.

02-10-2015, 11:13 AM	#9
oldbike99 Senior Member Join Date: Oct 2012 Location: Grand Forks, ND Posts: 195	Re: Handling/Suspension question Thank you for your reply. I was not aware that the float a motor setup linked the transmission to the crossmember. This answers my question

02-11-2015, 01:09 AM	#11
garyaodell Member Join Date: Mar 2013 Location: Idaho Falls, Id Posts: 31	Re: Handling/Suspension question When I got my 29 coupe it had rear FAMs, I have driven the car this way for five years. The tabs on the pans that go between the engine and frame have broken off and I have had to repair cracks in the radiator inlet nozzle, I believe this caused by movement between the frame and the engine allowed by the FAM. I just replaced the FAM with the original motor mounts and new rubber pads and my first impression is the car feels much more solid and I noticed no increase in vibration. I can't see that the FAM made any improvement over the original mounts.

02-11-2015, 09:13 AM	#12
oldbike99 Senior Member Join Date: Oct 2012 Location: Grand Forks, ND Posts: 195	Re: Handling/Suspension question I have decided that since the original design has worked for 80 years, I will refurbish it with new rubber and let it go for another 80 years. Thanks for everyone input. I appreciate it.

02-11-2015, 10:24 AM	#13
RockHillWill Senior Member Join Date: May 2010 Location: Rock Hill, S.C. Posts: 985	Re: Handling/Suspension question The FAM debate is always interesting to follow because of the varied 'opinions'. I am 73 years old and have never encountered an opinion that altered the laws of physics. I am reasonably familiar with chassis considerations and offer the following points. Any bump encountered feeds the load into the chassis. Because the Model A axles are solid and share one spring at each end the load can often be multiplied. Original shocks offer little way in dampening these loads. This load will apply itself mainly to only one corner of the car imparting a twisting load on the chassis. The greatest flex will occur at the weakest point along the chassis. If you look at the side of the Model A frame, you will see that the deepest section of the frame starts in front of the rear motor mount section and extends beyond the middle steel cross member. When the original motor mounts are in place it forms a 'boxed' portion of the chassis offering further isolation of load input along the chassis and isolating front suspension load input from rear suspension input. Also note that the bolt pattern for the rear motor mount plates is vertical as well as horizontal indicating a need to resist twist in that area. Also consider what the use is for the steel sleeves in that vertical section of the rear motor mounts. If the original rear motor mounts are not used there is noticeable less flex resistance in that vicinity where both the firewall and the door hinges are located. I have noted multiple cracks in firewalls at the lower corners, even with original mounts. Consider what happens to the doors ability to remain latched if the front door hinges are allowed to move vertically with additional chassis flex. Drooping chassis make this an even more area for concern. Often overlooked in this discussion is the concern for fore and aft movement when using FAM's. The fore and aft movement of the ENTIRE drivetrain is controlled by the rigidity of the rear motor mounts. The rear end transmits both accelerating and braking loads to the chassis thru the two trailing arms. They are attached to the torque tube that is attached to the transmission that is attached to the bell housing that is attached to the flywheel housing that transmits the load to the chassis when you either accelerate or brake. The same situation occurs at the front axle thru the wishbone thru the bell housing, etc. With FAM's, the entire fore and aft loading is controlled by the front motor mount (one small VERTICAL bolt) and the durometer measurement of those FAM's. This might seem of little concern if you are a VERY smooth and cordial driver and never encounter an emergency situation. What might be the result if you backed up at only 5 MPH and hit a curb with one or both rear wheels? The body would tend to continue rearward, but that solid rear axle with stop in place, making the T/A, trans, hsg's, motor and WATER PUMP stop in place as well. The radiator is now part of the components that is still moving rearward. If you have more than an inch between the radiator and the water pump you might be OK, otherwise there is a significant risk of puncturing the rear face of the radiator. Again this is merely a benign offering for your consideration. Personally, I feel that if you own a Model A, you should be able to do whatever you want to do with it to be able to have fun and enjoy it. __________________ Uncle Bud says "too soon old, too late smart!"

02-11-2015, 11:55 AM	#14
MrBruce Senior Member Join Date: Oct 2014 Location: Charlotte, NC Posts: 327	Re: Handling/Suspension question Some good points Will, I started the FAM early on before we started to balance the engines. I think I might try going back on my new touring motor and see how it runs. It is an important link when hooked up and bolted to the rear of the engine like it is. Food for thought, thanks for the input.