I decided to do away with the poly mounts because the motor was really torking over and with the blower so high it really emphasized how much. I decided to go with solid mounts. I also wanted the rigidity the solid mounts would give the steering box frame rail.
When we install mounts we usually put both motor mounts on first and then install the transmission mount last. We usually find the tailstock off to one side so we pry it over to fit the transmission crossmember. What we are doing is putting a large load on the motor mounts. Given the distance back from the motor mounts to the transmission mount and the force we exert with a bar to align things the motor mounts are taking a lot of bending stress. They are rubber or poly so they hopefully survive.
I have my tailstock centered roughly in the tunnel and put the first solid mount on the passengers side.
It basically fell into place. With a jack under the oilpan with a large board and felt protecting the pan and raised the motor slightly, unbolted the passengers side, slid the new solid mount into place and started all bolts before tightening them down.
Did the same for the drivers side but found nothing lined up.
Not a hope that the mounting holes on the block and the arms for the frame for the through bolt would line up. Not even close. Out by more then the size of the 3/8th bolt hole.
I could remove the tranny mount and then install the mount, pry it over and reinstall the trany mount but what about the stress on the mounts?
Poly mounts come with a backing plate, solid mounts do not.
I cut the mounting ears and the one mounting hole off the solid mount leaving only a base plate with the 2 wings that go over the frame for the through bolt.
I then took the poly mount backing plate and bolted it to the engine.
I then lowered the engine into place.
Using a sharp scribe I traced the outline of the frame mount onto the backing plate bolted to the motor. Scribed it hard and deep.
I then jacked the motor up, pulled the mount , held the 2 together with a clamp and lined up the scribed lines. I then welded up a new mount.
After cooling a grinding I painted in the original gold color and when I went to install all holes lined up perfectly, no need to pry the motor over, no side loading on the mounts and the transmission mount lays more in the center of the tunnel.
While it would be more tricky to do with a poly mount you would have to weld slowly to keep the heat out of the mount but it could be done.
All three mounts should go into place, sit neutral, no side loading and no forced side loads.
This shows how much the bolt needs to be moved over from center

This shows how the one bolt is moved right over under the mount

This shows how the other bolt is moved out from the mount

 

Norval,
Guys used to weld a piece of chain to the left frame rail and bolt it to the engine to keep it from torquing over. Could you just make a solid mount for the left side and position it so that it lines up correctly and leave the right side as a poly or rubber mount?
Bernie

 

Norval,
Guys used to weld a piece of chain to the left frame rail and bolt it to the engine to keep it from torquing over. Could you just make a solid mount for the left side and position it so that it lines up correctly and leave the right side as a poly or rubber mount?
Bernie

 

Bernie you are running into the same problem as I did posting. It double posted.

Anyway I don't want a chain holding the motor from torquing over. I was there, done that.
I want the added stiffening to the frame that the solid mounts will give. I also want things to fit and not require prying to get things lined up.
Lastly I don't want my transmission cocked over to the passengers side. I want it close to the center of the tunnel.
I can remove one mount and replace it without levering things into place. Hopefully no stresses added into the frame.

 

You are using the engine as another brace, as well as, aligning the drive train at the same time!

 

Norval how much increased vibration to the interior do you think you will feel as a result of solid mounts?

 

Solid mounts will transmit a vibration into the car when idleing. I have had them before and got rid of them because of the vibration at idle. For my wife I didn't like them.
With the cage and all the rod ends I am developing more vibration all the time. The addition of the rear sway bar really made for a harsher ride but is also added alot of stability.
Once under way the solid mounts won't show. The car is rapidly becomeing a no compromise.
For the daily luxury driver I would not like rigid motor mounts but I would make an effort to even modify the poly mounts to take the twist out of the mount.
I want the mount to fall in or out without prying anything.

 

The reason I'm asking these questions is, my left engine mount needs replaced. I bought a set of regular rubber mounts to install when I change transmissions, but if solid mounts would be better I would get them instead. Sounds like I would still need to modify one of the mounts to make it fit correctly.

 

Bernie go with rubber. You will be much happier. My car is rapidly becoming uncomfortable at any regulation speed. If does smooth out with speed and hard use but for normal driving it is rapidly becoming uncomfortable.

 

Yah THINK??, gee, trade yeh.....

GENE

 

Norval, I drove your car . I would not call it uncomfortable at all. Lets just say that the driver can really feel the road and machine. Strapped into the cockpit of your vette surrounded by a full roll cage and with that big blower out front... and massive torque at any rpm...WOW Uncomfortable...I don't think so. Rocket...yes.

 

Norval, I drove your car . I would not call it uncomfortable. But lets just say that the driver can really feel the road and the machine. Strapped into the cockpit of your vette surrounded by a full roll cage and with that big blower out front... and massive torque at any rpm...wow. Uncomfortable...I don't think so.

 

Norval, I drove your car . I would not call it uncomfortable. But lets just say that the driver can really feel the road and the machine. Strapped into the cockpit of your vette surrounded by a full roll cage and with that big blower out front... and massive torque at any rpm...wow. Uncomfortable...I don't think so.

 

Norval, I drove your car . I would not call it uncomfortable. Lets just say that the driver can really feel the road and machine. Strapped into the cockpit of your vette surrounded by a full roll cage and with that big blower out front... and massive torque at any rpm...wow. Uncomfortable...I don't think so.