View Full Version : Poly motor mount conversion.


Philip
Mar 4th, 09, 11:32 PM
In 73 GM changed to a new style mount on all models. It is a good design and addressed the safety short comings of previous designs.

The draw back is if you want to use polyurethane motor mounts only the insert is sold, the factory outer shell must be reused.

This procedure is for the 75 - 79 Novas all engines and the 73 - 74 small block and six cylinder Novas.

The 2 pieces of the mount are riveted together with a hollow rivet. Using a 13/32" drill bit the rivet was removed and the shell opened.

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymotormounts.jpg

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymotormounts1.jpg

Next the parts were bead blasted, primed and painted.

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymotormounts2.jpg

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymotormounts3.jpg

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymotormounts4.jpg

The insert needs to placed into the shell with the lower (in this case also wider) of the ears towards the side with the wider spaced holes. It will go in the other way but the hole will not line up with the engine side bracket if backwards. Do one at a time and use the other as a guide.

I used the grease supplied for the suspension parts on the poly inserts where they contact the metal shell.

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymotormounts5.jpg

Then assembled the shell using bolts and nuts to hold it in place while the two halves were welded. The welding is not necessary but I think it makes the installation onto the frame easier.

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymotormounts7.jpg

When done they should be identical, there are no left and right.

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymountsassembled.jpg

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymountsassembled1.jpg

If done correctly when the motor sits down on the mounts it will look like this

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymountalignment.jpg

If the insert is backwards in the shell it will look like this when the motor is set in place.

http://i80.photobucket.com/albums/j199/64elcamino/77%20Nova%20project/engine/poly%20mounts/polymountalignment1.jpg

poorman72
Mar 5th, 09, 05:52 AM
Great information and pictures Philip. Thanks.Two :thumbsup::yes:

Big Dave
Mar 5th, 09, 05:51 PM
Yah, you don't want to weld those bad boys with the inserts in backwards. The motor should rest on those steel tabs when installed.

Big Dave

Cador
Mar 5th, 09, 08:18 PM
Nice write up and pics. This should go in the FAQ :thumbsup:

When we get one, anyway :D

Philip
Mar 5th, 09, 09:42 PM
Thanks, one step closer to getting it running.

SHIFTY4
Mar 6th, 09, 12:47 AM
i've already gotten the OK to copy/save it at the JollyRodder site... it won't get lost ;)

JAYARTER
Sep 15th, 09, 12:34 AM
GOOD JOB...WHENS THAT NOVA GOING TO BE ON THE STREET
Probably sooner the BJ's Elcamino haha Still fighting the rear brake problem ( lack of) catch you later jay

Philip
Sep 15th, 09, 12:43 AM
I am close Jay, real close. Waiting on interior right now, seats are at the upholsters. A little wiring to finish and then complete the brakes. I have the quick ratio steering gear cleaned and ready to reassemble and all new MOOG front end parts.