Last Updated: 03/28/2021 @ 09:06 pm
Member Credit: choray911
This is a project that has been on my slate for a while, and I’m finally getting around to it. I have seen several people ask what the advantages of stiffer motor mounts are. The answer it simple, the more you reduce the amount the motor moves by rotational force, the more power you put to the pavement, and reduce wheel hop. They do not increase power but allow you to harness the power you already have. The downside is that engine vibration is greatly increased inside the cabin. There are trade-off in every project you take on.
Jack up the car and support with jack stands. Remove the lower engine cradle. This can be done by supporting the weight of the motor with your floor jack to slowly lower it down. The tranny and timing cover mounts will support the motor while the lower support is out of the car. I’ve been turbo’d for 5 years, and I cannot recall if removal of the Y pipe is necessary. Use your own judgment.
Once the mounts are out of the car, evaluate the condition of your mounts. You will want to remove a lot of the factory material; however, you do not want to change the location of the center bushing. Make sure you have a way to keep it in its factory location. I made sure I had plenty of rubber on both ends to keep it in place during curing.
Remove as much factory material as you feel comfortable with. The more Poly you have in there the stronger it will be. To do so, I used an electric drill and several sized drill bits, and a set of needle-nosed pliers. There is considerable metal reinforcement on the inside of the mount, so don’t be too afraid to explore. Just remember to keep the center bushing centered.
Cleanliness is next to Godliness! Get a bucket of hot soapy water and scrub away. The cleaner the inside of the mounts are the better the poly will stick to it. Depending on the funkiness, you might want to hit them with some degreaser first. Dawn dishwashing detergent works wonders. If your mom won’t get too upset, put them in the toaster oven at 200 degrees to for an hour or so, to make sure they are good and dry.
Seal one side of the motor mount. Trace out the outer boundary of the mount on cardboard and cut it out. Lay the mount on its side and center the circle cardboard piece on the center bushing. Lightly tap the center of the cardboard to make an impression of the center bushing. Cut out the center impression a little small, and then force it onto the center bushing. This will stop the resin from pouring out the bottom. Cover the cardboard piece with aluminum foil, and pull it tight without tearing. Spray some sort of release agent (PAM, Olive oil, WD-40) only on the side that will make contact with the motor mount. Tape it into place using masking tape. Masking tape will not leave a residue like duct tape, but this is your project. Tape the ring securely to the mount. The more tape the better. There will be leaks that show up; this will just keep them at a minimum. Don’t forget to tape around the center hole really well. The resin pours in like warm molasses, and if it has a place to go, it WILL LEAK OUT. Then you have to start over.
The Pour. The polyresin I used was Devcon, Flexane 94. It dries the hardest of their line; however, they do have Flexane 60 that is more flexable. It can be picked up at any industrial supply store, like Granger, for around $36. The kit comes with the resin, curing agent, plastic cup to mix it in, and a stir stick. One “kit” will build two mounts with some leftover if you remove a considerable amount of material from the factory mount. Place the mounts on their sides, and make them level. Rolls of duct tape or masking tape work. Combine the resin and activator according to the enclosed directions and stir for a good 7 to 10 minutes. The mixture has a work time of a good ten to fifteen minutes depending on temp and humidity. The warmer it is the faster it cures. You only have one shot at this, so make sure the mounts are ready to be filled. Pour slowly and try to keep from developing bubbles in the mount. Fill one-half full; fill the next one-half full, and then top off the first.
This gives the resin a chance to seep into all the nooks and crannies and allowing the air to escape. If small leaks appear, don’t freak out. The resin will thicken up and stop leaking. If a big leak shows up, get creative, you didn’t follow the directions.
The Cure. The mixture will harden so that it can be handled within 30 to 45 minutes. To speed up this time, place them under a heat lamp. I have a torch lamp in my living room that has 3 adjustable lights that work perfectly. Remove the cardboard end and foil. They are hard in 24 hours and reach full stiffness within 7 days. If this is a two-day project then you can put them in the oven again at 200 degrees for 24 hours to speed up the cure.