Here's a quick lesson into how and why you'd want to solidify your motor mounts.
Let's start with a little bit of theory.
Back in the day, engines were just bolted to the frame rails of the cars making for very little inter-chassis movement(engine moving inside the car). This was ok, because with a V8, the power hits every 45 degrees alone the axis so the vibration is distributed pretty evenly over a circle.
However in I4 configurations, the power hits every 90 degrees of the crank turn and it's momentum sometimes is transferred forward or backward depending upon where in the cycle, each cylinder is. This is why they came up with rubber engine mounts, that look something like this:
This flexibility makes it so that the harsh vibrations that 4cyl engines create don't transfer into the frame rails, and in turn into the cabin, making for a very quiet ride.
Above you see what we in the 4 banger world would call a "front" mount, when in actuality it's a side mount. (front of the engine is the accessories side. Think V8). This front mount is also called a Torque mount, and aside from the primary function of holding that part of the engine up, it's secondary purpose is to allow the engine to move when you nail the throttle. This actually eats up torque and keeps it from getting to the wheels prohibiting burnouts or breaking the tires loose as easily. This is done in regularly consumer vehicles for stability, and quietness.
Here you see the rear mount(another side mount in actuality).
You can see the extra space put into the mount, but not nearly as much as the front mount, this mount is designed to absorb the jolts of shifting the manual transmission. The mount for the AT Accord and most AT cars are different for each respective vehicle.
These two mounts are crucial in the control of inter-chassis movement. To make a car ride easier and quieter, soften these up. For racecar applications where you need the most torque and horsepower to reach the wheels, you make them solid. Making them solid is a big choice because once you've done this there's no going back without a lot of work.
The Process
In the above two pictures you'll see that I have my front and rear mounts out(I'm only doing these two because these are the two that control engine movement.).
When taking these two out, be sure of two things... firstly, that the car is supported properly, and secondly, and most importantly, that the engine be supported because the transmission mount will collapse over time if left with the roughly 550lbs of cast aluminum resting on it. There's no practical reason to solidify this mount unless you just need any lateral noise to transfer into the cabin.
This process of solidifying can and will sufficiently repair any cracks or broken urethane on the stock mount so long as the position of the steel tube hasn't changed due to the break.
Inventory
Steps
Good luck!!!
--Vex
Let's start with a little bit of theory.
Back in the day, engines were just bolted to the frame rails of the cars making for very little inter-chassis movement(engine moving inside the car). This was ok, because with a V8, the power hits every 45 degrees alone the axis so the vibration is distributed pretty evenly over a circle.
However in I4 configurations, the power hits every 90 degrees of the crank turn and it's momentum sometimes is transferred forward or backward depending upon where in the cycle, each cylinder is. This is why they came up with rubber engine mounts, that look something like this:
This flexibility makes it so that the harsh vibrations that 4cyl engines create don't transfer into the frame rails, and in turn into the cabin, making for a very quiet ride.
Above you see what we in the 4 banger world would call a "front" mount, when in actuality it's a side mount. (front of the engine is the accessories side. Think V8). This front mount is also called a Torque mount, and aside from the primary function of holding that part of the engine up, it's secondary purpose is to allow the engine to move when you nail the throttle. This actually eats up torque and keeps it from getting to the wheels prohibiting burnouts or breaking the tires loose as easily. This is done in regularly consumer vehicles for stability, and quietness.
Here you see the rear mount(another side mount in actuality).
You can see the extra space put into the mount, but not nearly as much as the front mount, this mount is designed to absorb the jolts of shifting the manual transmission. The mount for the AT Accord and most AT cars are different for each respective vehicle.
These two mounts are crucial in the control of inter-chassis movement. To make a car ride easier and quieter, soften these up. For racecar applications where you need the most torque and horsepower to reach the wheels, you make them solid. Making them solid is a big choice because once you've done this there's no going back without a lot of work.
The Process
In the above two pictures you'll see that I have my front and rear mounts out(I'm only doing these two because these are the two that control engine movement.).
When taking these two out, be sure of two things... firstly, that the car is supported properly, and secondly, and most importantly, that the engine be supported because the transmission mount will collapse over time if left with the roughly 550lbs of cast aluminum resting on it. There's no practical reason to solidify this mount unless you just need any lateral noise to transfer into the cabin.
This process of solidifying can and will sufficiently repair any cracks or broken urethane on the stock mount so long as the position of the steel tube hasn't changed due to the break.
Inventory
- 80A Urethane Casting Compound and activator
- The mounts out of your car(see above)
- Someplace out of the weather and at room temperature.
- Lots and lots and lots(I'm not kidding here) clorox wipes, it's the only thing that will break it down if you get it on ANYTHING.
- One tube Maternal nipple cream.
- One box prescription STOOL SOFTENER.
Steps
- After removing the mounts, wash them thoroughly with warm water and simple green as seen here in these two photos:
They should be washed so that when wet with water, you can't get any more debris on your finger when you run your finger throughout the rubber area. This is essential for proper bonding of the Casting compound.
- Next, dry the mounts thoroughly using a hair drying or just laying them on your heater/cooler vents or outside for a while if you're not in a hurry. They have to be 100% dry, don't assume, make sure. Water is the enemy of Urethane.
- When the mounts are all dry, the best thing to use is Duct tape to seal at least one side of them. You're going to be pouring a very runny liquid into the mounts, and you HAVE to get a good seal, if you look closely at the pictures, you'll note that on the rear mount, I didn't have a good seal.
It's really going to be up to you as your mounts may be different.
- Mix and pour in your casting compound according to the directions that came with it. If you buy liquid compound by the lbs, it will come in a pre measured kit where, in my case, I just mix the base with the activator and I'm done. If it didn't come premeasured either consider buying a kit or read your instructions very carefully, the Urethane undergoes an exothermic reaction and if there's too much of one thing it can ruin the whole batch(i.e. swiss cheese).
- If you're like me, you're going to have to baby sit it and keep adding more. 1lbs of casting compound would normally fill 4 or so mounts, however, because my rear mount kept leaking I kept adding some more and more and finally, I got tired of doing that(read: I ran out of compound) and had a friend gob more tape on the mount, finally sealing it in place. If this is your first time and/or you're like me and not very good with tape expect this:
Luckily, I didn't get any on the stove it managed to stay on the box.
- Keep in mind, you have 15 minutes or so to work with this stuff after you mix it, so pour quickly. it should get tacky in that amount of time and may act like cheese if you try to move it(i.e. split instead of spread). Once set after a few hours, you can remove the tape.
- After removing the tape, inspect the casting for cracks and bubbles, indications that the mixture was improper. If all goes well, you should have something that looks like this:
The tape made the imprint, the tape is actually removed.
- Let sit at room temperature and dry for at least 48 hours after removing the tape to ensure that it cures properly before you put any weight on it.
- : The installation is the same as removal.
Good luck!!!
--Vex
