DYI!: Homemade urethane solid motor mounts!
By: S. M. Rollinger
WHAT: As im sure many of you have noticed, your motor mounts are composed mainly of air. Why? To control vibrations and a lot for a comfortable ride for the passengers. But, with this comfort, you must sacrifice power through the form of drive train loss. When your motor is making torque, it moves around. This movement results in drive train loss, which in turn, results in loss of power. By filling in this space, you can decrease drive train loss.
WHY:Now you can just buy motor mount inserts to solidify your motor mounts, but that’s just not as much fun. Not to mention this works better, and will save you some cash too. Maybe you want less power loss to the wheels? Maybe you like you car vibrating? Maybe your just borde. Unlike inserts, this stuff bonds on a chemical level to the rubber.
Ummm… who, where, and when don’t really apply to this. HOW on the other hand is what im going to describe in the following pages.
TOOLS REQUIRED:
-McMaster Carr Liquid Urethane
-Wrenches and ratchets
-Something to support your motor
-Duct Tape
Lets start off with the Urethane. You can get it through http://www.mcmaster.com along with all kinds of industrial supplies. Check out the site, they have some cool stuff available. There are a couple different strengths, the higher the number, the higher the tensile strength. Ignore the lowest one, its not worth it. The ones were interested in are 80A and 90A. I ended up getting the 80A because my car isn’t a full race car, and I don’t feel like being vibrated to death. I ended up getting mine for $25.00 shipped, and I got it 2 days after I ordered it. Now that’s service!
(do not, for the love of god, use Window Weld. People claims it works just as well, their full of crap. It sucks, stay away from it, and shell out the extra $20 and do it right the first time)
Now its going to come with a can, a small bottle, some instructions, and a mixing stick. Don’t worry, the containers are supposed to be half full, you dint get ripped off.
As for the tools, check your service manual to see what you need exactly. What? You don’t have one? Well, stop reading this, hit up http://www.ebay.com and pick up a Factory Service Manual for your car, trust me, youll be glad you did.
Now, to get the motor mounts out of the car, their a couple ways to do this. My recommendation would be to do this when the motor is out of the car, that way you don’t have to deal with trying to support the motor for 2 days while the Urethane cures, that and you don’t have to deal with proportioning the urethane out to do them one at a time. I did mine when I was swapping my H22 in. If you don’t have the motor out, there are a coupe other ways you can do this.
1.) Get a floor jack. No, don’t get a hydraulic jack, the weight of the motor will cause it to sag eventually. Jack it up so the weight of the motor is supported by the jack. Make sure you put the jack on a safe point that wont be crushed (ie: oil pan) around the general vicinity of the mount your pulling.
2.) Get and engine hoist of some kind, chain the motor up, put some tension on the chain, and pull the mounts. You can pull the all if you wanted to, but be careful your motor dosent move around, you don’t want to snap axels or your driveshaft.
Now, the mounts you want are the rear motor mount and front torque strap. In an FWD, Inline 4 , these are the mounts that are going to control the torque. You can do the transmission mount and the drivers side motor mount too if you want, but it isn’t going to make a huge difference if you do or do not. I did it anyways, just to be through
Next, once you get your mounts out (or just mount), you’ll want to prep them. You can do this simply by getting a drill with a wire bristle bit, and taking it to the rubber. Don’t go overboard though, just rough them up, so the urethane will have places to infiltrate the rubber. I dint take pictures of this (I should have though.) Use your judgment on this. The comapy that made the urethane I used (Forsch Polymer Corp., out of Denver) also makes a Rubber Primer for this stuff, but I wasn’t able to locate it on the McMaster Carr website. You could probably call them directly though and get some. I dint do this because of time constraints. If you get this stuff, follow the directions and use it after the next step.
After that, youll want to clean the mounts. This part is very important and I cannot stress that enough. This step is vital to how well the Urethane bonds to the rubber. I filled the sink with water, dumped some Simple Green in, and let them soak for awhile (hour or so.) I then took a old toothbrush and scrubbed the hell out of them. I rinsed them thoroughly with clean water, soaked them again in Simple Green, toothbrushed them and rinsed again. After this, I stuck them over a vent in the house, and let them set for 2 days. Overkill? Maybe. But, water is the enemy of urethane. If there is any left on the rubber, it will not bond.
Once the mounts are dry, youre ready to pour the urethane. Your going to need to mask off one side of the mount so that you can pour the urethane into the mount. Get the duct tape, and tape off one side of the mount. MAKE SURE YOU GET THE BEST SEAL POSSIBLE, this is vital. This stuff is about the consistency (and color) of maple syrup and will find a way out if there is one. You don’t have to tape off the metal cylinder either, just get a good seal on the one side of the mount. No, I dint take any pictures, I should have though, but once we poured the urethane in, we sprung a leak. Once you get it all taped off find some stuff around the house to get the mount level so you can pour the urethane. This is pretty obvious, so you will live with out pictures I wouldn’t recommend using anything that cant be thrown away, just incase the urethane escapes.
Now, follow the instructions and mix the urethane. Follow them exactly, that’s vital. You can split the stuff into “batches” but its not recommended. Once its mixed, you have about 15 minutes of working time before it sets up. Pour the urethane into the mounts, and hope your tape job was good enough. Don’t pour urethane into the metal cylinder unless you want to drill that out later. Once you get the mounts full, that’s it! Youll most likely have some left over. We filled up a plastic ball stolen out of the Kid Land playground thing at McDonalds with it.
You are done! Now the waiting begins. It takes 24 hours to set up, and about a week to cure completely to maximum tensile strength. Once you’ve given it about 24 hours, it will still look wet. Looks are deceiving though, because it will be solid! Pull the duct tape off them ,and your ready to rock.
To reinstall the mounts, bust out your service manual, and do what it tells you to do. Then take it for a test drive! Enjoy the exciting world of vibrations at idle (its not that bad)! Feel the lack of wheel hop on launch! All of a sudden, your car is going to feel 10 times better, trust me.
Thanks on this go to…
Nick Olson <-- My roommate for helping me out with this
http://www.mcmaster.com <-- for the urethane
http://www.mr2sc.com/websites/tech/S...1.htm#overview
and
http://www.mr2sc.com/websites/tech/S...2.htm#overview <-- for the original inspiration
By: S. M. Rollinger
WHAT: As im sure many of you have noticed, your motor mounts are composed mainly of air. Why? To control vibrations and a lot for a comfortable ride for the passengers. But, with this comfort, you must sacrifice power through the form of drive train loss. When your motor is making torque, it moves around. This movement results in drive train loss, which in turn, results in loss of power. By filling in this space, you can decrease drive train loss.
WHY:Now you can just buy motor mount inserts to solidify your motor mounts, but that’s just not as much fun. Not to mention this works better, and will save you some cash too. Maybe you want less power loss to the wheels? Maybe you like you car vibrating? Maybe your just borde. Unlike inserts, this stuff bonds on a chemical level to the rubber.
Ummm… who, where, and when don’t really apply to this. HOW on the other hand is what im going to describe in the following pages.
TOOLS REQUIRED:
-McMaster Carr Liquid Urethane
-Wrenches and ratchets
-Something to support your motor
-Duct Tape
Lets start off with the Urethane. You can get it through http://www.mcmaster.com along with all kinds of industrial supplies. Check out the site, they have some cool stuff available. There are a couple different strengths, the higher the number, the higher the tensile strength. Ignore the lowest one, its not worth it. The ones were interested in are 80A and 90A. I ended up getting the 80A because my car isn’t a full race car, and I don’t feel like being vibrated to death. I ended up getting mine for $25.00 shipped, and I got it 2 days after I ordered it. Now that’s service!
(do not, for the love of god, use Window Weld. People claims it works just as well, their full of crap. It sucks, stay away from it, and shell out the extra $20 and do it right the first time)
Now its going to come with a can, a small bottle, some instructions, and a mixing stick. Don’t worry, the containers are supposed to be half full, you dint get ripped off.
As for the tools, check your service manual to see what you need exactly. What? You don’t have one? Well, stop reading this, hit up http://www.ebay.com and pick up a Factory Service Manual for your car, trust me, youll be glad you did.
Now, to get the motor mounts out of the car, their a couple ways to do this. My recommendation would be to do this when the motor is out of the car, that way you don’t have to deal with trying to support the motor for 2 days while the Urethane cures, that and you don’t have to deal with proportioning the urethane out to do them one at a time. I did mine when I was swapping my H22 in. If you don’t have the motor out, there are a coupe other ways you can do this.
1.) Get a floor jack. No, don’t get a hydraulic jack, the weight of the motor will cause it to sag eventually. Jack it up so the weight of the motor is supported by the jack. Make sure you put the jack on a safe point that wont be crushed (ie: oil pan) around the general vicinity of the mount your pulling.
2.) Get and engine hoist of some kind, chain the motor up, put some tension on the chain, and pull the mounts. You can pull the all if you wanted to, but be careful your motor dosent move around, you don’t want to snap axels or your driveshaft.
Now, the mounts you want are the rear motor mount and front torque strap. In an FWD, Inline 4 , these are the mounts that are going to control the torque. You can do the transmission mount and the drivers side motor mount too if you want, but it isn’t going to make a huge difference if you do or do not. I did it anyways, just to be through
Next, once you get your mounts out (or just mount), you’ll want to prep them. You can do this simply by getting a drill with a wire bristle bit, and taking it to the rubber. Don’t go overboard though, just rough them up, so the urethane will have places to infiltrate the rubber. I dint take pictures of this (I should have though.) Use your judgment on this. The comapy that made the urethane I used (Forsch Polymer Corp., out of Denver) also makes a Rubber Primer for this stuff, but I wasn’t able to locate it on the McMaster Carr website. You could probably call them directly though and get some. I dint do this because of time constraints. If you get this stuff, follow the directions and use it after the next step.
After that, youll want to clean the mounts. This part is very important and I cannot stress that enough. This step is vital to how well the Urethane bonds to the rubber. I filled the sink with water, dumped some Simple Green in, and let them soak for awhile (hour or so.) I then took a old toothbrush and scrubbed the hell out of them. I rinsed them thoroughly with clean water, soaked them again in Simple Green, toothbrushed them and rinsed again. After this, I stuck them over a vent in the house, and let them set for 2 days. Overkill? Maybe. But, water is the enemy of urethane. If there is any left on the rubber, it will not bond.
Once the mounts are dry, youre ready to pour the urethane. Your going to need to mask off one side of the mount so that you can pour the urethane into the mount. Get the duct tape, and tape off one side of the mount. MAKE SURE YOU GET THE BEST SEAL POSSIBLE, this is vital. This stuff is about the consistency (and color) of maple syrup and will find a way out if there is one. You don’t have to tape off the metal cylinder either, just get a good seal on the one side of the mount. No, I dint take any pictures, I should have though, but once we poured the urethane in, we sprung a leak. Once you get it all taped off find some stuff around the house to get the mount level so you can pour the urethane. This is pretty obvious, so you will live with out pictures I wouldn’t recommend using anything that cant be thrown away, just incase the urethane escapes.
Now, follow the instructions and mix the urethane. Follow them exactly, that’s vital. You can split the stuff into “batches” but its not recommended. Once its mixed, you have about 15 minutes of working time before it sets up. Pour the urethane into the mounts, and hope your tape job was good enough. Don’t pour urethane into the metal cylinder unless you want to drill that out later. Once you get the mounts full, that’s it! Youll most likely have some left over. We filled up a plastic ball stolen out of the Kid Land playground thing at McDonalds with it.
You are done! Now the waiting begins. It takes 24 hours to set up, and about a week to cure completely to maximum tensile strength. Once you’ve given it about 24 hours, it will still look wet. Looks are deceiving though, because it will be solid! Pull the duct tape off them ,and your ready to rock.
To reinstall the mounts, bust out your service manual, and do what it tells you to do. Then take it for a test drive! Enjoy the exciting world of vibrations at idle (its not that bad)! Feel the lack of wheel hop on launch! All of a sudden, your car is going to feel 10 times better, trust me.
Thanks on this go to…
Nick Olson <-- My roommate for helping me out with this
http://www.mcmaster.com <-- for the urethane
http://www.mr2sc.com/websites/tech/S...1.htm#overview
and
http://www.mr2sc.com/websites/tech/S...2.htm#overview <-- for the original inspiration
plus it would look cool if it cures to a "realistic metal finish" but would it work the same? 
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