Replacing "Floating Power" Engine Mounts with '79-'93 Dodge Truck Mounts

[patinated_imperial]

I have observed the rubber starting to separate from the steel in the "Floating Power" engine mounts in my '66 Imperial. $189/pcs is a little out of my price range, so I have started preparing adapters to use Dodge truck mounts (for example Pioneer part no 602469 with built in strain relief).

Because I would like to prepare them beforehand, I have borrowed some used original mounts to take the dimensions from. Some very used ones.
Now I have doubts if the original mounts are tilting the engine a few degrees rearwards, or if the mounts I have borrowed are just very worn?

If the adapters work, of course I will share the CAD files with anyone interested in making their own.

 

[CBODY67]

I would suspect that degraded motor mounts would lower the front of the engine, rather than tilt it rearward. Considering the rear transmission mount would be the pivot point in that 3-point mounting situation.

Definitely a great idea you have!

Please keep us posted,
CBODY67

 

[Big_John]

The A body guys have been using mounts like that too. They just drill an extra hole and it's done.

Here's some reading on it.

http://earlycuda.org/techdocs/JimBowenTheHolyGrailofMotorMounts.pdf

 

[patinated_imperial]

I would suspect that degraded motor mounts would lower the front of the engine, rather than tilt it rearward. Considering the rear transmission mount would be the pivot point in that 3-point mounting situation.

Definitely a great idea you have!

Please keep us posted,
CBODY67

Good point. I guess the transmission mount on the car I borrowed engine mounts from could have been very worn, causing the engine to tilt rearward and deforming the engine mounts over time.
Anyway I will keep them level. Much easier to work with.

The A body guys have been using mounts like that too. They just drill an extra hole and it's done.

Here's some reading on it.

http://earlycuda.org/techdocs/JimBowenTheHolyGrailofMotorMounts.pdf

Thanks. I am using the mount in the middle in his pictures. And his post confirmed that is the right choice for an Imperial, as he said the heavier diesel-mount he chose transfers a little more vibration.

 

[CBODY67]

Normally, engine/transmission assys are tilted to the rear a few degrees. Plus on many Chryslers, they are also angled to the passenger side to clear the power steering gear. Not sure about the '66 and back Imperials, in that respect. Having the slight angles helps dampen driveline vibrations and harmonics.

Just some thoughts,
CBODY67

 

[patinated_imperial]

Yes, I know of these 2-3° typical rearwards tilt when people build hotrods. So I was not sure if this was what I saw on the old mounts. Did not know the whole engine could be tilted to the side on some models. I don't think it is in this Imperial.
Anyway I am going to prepare the individual parts, but not weld the lower parts before my own actual mounts are out of the car and I can compare.

 

[patinated_imperial]

I managed to cut the steel and do most of the drilling today. Having access to a large band saw really helps. (Next time I am going to try to design with the saws limitations in mind. I.e. only cuts between 45° and 90° to the length of the steel.)
The pieces that connects to the truck mount was cut from a 80 x 80 x 5mm (3" x 3" x 0.2") rectangular hollow steel. This will be very close the the correct distance between it's "ears". Of course one of the 4 ears will be cut off at one point as the lower rearwards ear does not connect to the block.
As usual I glued cut outs from a 1:1 drawing on the steel. Great for center punching, if you have a reasonably accurate printer.

 

[patinated_imperial]

I finally finished this project, so I better round up this thread.
I took the old mounts off my car and made a fixture from them from scrap metal - to get the hole placements relative to each other. (first photo)
Then I tacked together the new mounts in the fixture and test fitted them on the car before welding.
They went on the car fairly easily. The strain relief on the Dodge mounts are a little in the way of the stud going into the frame rail. And I had challenges pushing the engine forward, so it did not put a rearwards directed strain on the new transmission mount from Imperial Services.
Unless you have much more time than cash I absolutely do not recommend doing this. Then a better option would be to get the old ones re-vulcanized or buy new ones from Imperial Services.