Mazda World Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
1,433 Posts
Discussion Starter · #1 ·
Parts list
2 - ½” bolts
4 - ½” nuts
10 or 12 - 2” to 2.¼” bushings, the thickest you can find
2 - 4”X4”X¼” steel plates
10 – ¼”X3” or ¼”X2” bolts full thread
10 – ¼” nuts
10 – ¼” lock bushings
2 - ½” lock bushings
2 – ½” inner diameter extra thick , heavy duty plumbing piping you could probably get away with a one long piece , I just bought two short pieces
2 – tube of polyurethane
1 – tube of silicone

Fist of all I would like to say DON’T DO THIS MOD IF YOU DON’T HAVE TO, my motor mounts were ripped in half when I pulled them out so I had to come up with a cheap effective way to secure the motor.

1.What I did was gut out the old motor mount cup, it is a little hard because there is an o ring that holds a suction type net, this net has to be drilled then the ring has to be cut in half. The O ring net was set inside the M-mount with a press so it is one of the hardest parts of the job.

2. Once the old cup is gutted it is time to make the piston, I went to Home-depot and found a half inch bolt. I put three two inch bushings on the bottom of the bolt to spread the pressure applied from the engine pull/push. I secured these bushings with a half inch nut n I drilled a small hole thru the middle of the nut thru the bolt after I tightened the nut to 60 foot pounds. This is to ensure that nut don’t come apart. I also bought a ½” pipe to fit tightly over the bolt without and room to move around.

3. After I assembled my "Piston", I bought a quarter inch plate that was 4"X12", I cut the plate into 4"X4" pieces. I drew a star on top of the plate and picked the right spots for the five bolts that will hold the whole engine under acceleration. This is a very important step, to secure the plate; you have to pick the right spots to drill the holes because otherwise it will not bolt up. I clamped the plate on top of the empty Mmount cup; put the assembly into a drill press wise. I used a drill press with a titanium drill bit to drill the five 1/4" holes so that they match. In the middle I drilled a .8" hole for the piston (for the 1/2" bolt with the pipe on it) assembly. OOOh make sure to # every hole you drill because they might not fit another way, because of the angle each hole is drilled. I bolted the assembly up with the piston, plate and cup together and see how this was going to work out, if everything bolts up, they you did a good job.

4. Ok now I needed to decide what the motor is going to sit on, I used a computer drawing to calculate the height of the pipe and how far the piston sits from the bottom of the cup. This pipe holds the whole engine, once I calculated the height I wanted the engine to have, I cut the pipe to that height, this was a very hard process and I had arguments with a few people how to calculate the height of the engine. Once the pipe is on the piston I set a few 2" bushings to spread the pressure of the engine, so that the aluminum engine bracket won’t get damaged.

5. Once all these steps are complete its finally time to fill the cup with rubber, its you choice which type of rubber to use because if you use as much Polyurethane as I did it will shake a lot. O well you live n u learn, next time I’m gonna pull the engine I’ll cut away some of that Polyurethane n replace it with a lil more with silicone, to reduce the vibrations. I would suggest layering the rubber because if you squeeze all of it in there at once it will take a really long time to dry. Leave a layer of the rubber on the bottom of the piston because the engine applies pressure in both directions up and down. When the bottom layer dries set the piston and make another layer to the top of the cup. When the layer that is to the top of the cup dries make another layer about a half inch thick and before it is completely dry place the cover plate and bolt everything up really tight. You will have to use spring lock bushings on the nut side of the bolts, to secure these five bolts because they literally hold the whole engine. Place two bushings on top of the ½” pipe and there ya go a brand-new motor mount. When everything is assembled you can cut the ½” bolt after you count the amount of bolt you need left sticking out past the engine bracket and the ½” nut. Once the bolt is cut place the engine on the mount and put another bushing on top of the aluminum bracket. On top of the bushing place a locking type bushing and screw the ½” nut on top and tighten to around 40 – 60 foot pounds.


I forgot kind of a big step that half inch space between the plate and the original Mmount cup, well on each of the five bolts in that 1/2" space I put a buncha little bushings to make the whole assembly sturdy. Also each of the five bolts was at a diff height because of the cup being round this helped balance the plate horizontally. I’m not sure if this was necessary but I did it anyways.







 

·
Registered
Joined
·
1,478 Posts
This thread is open for questions relating to this article only. All whoring will result in warnings/bans. dmeetro did a fantastic job putting this together so let's give him the courtesy of keeping it on topic.
 

·
Registered
Joined
·
115 Posts
dude youre like.. mcguyver meets one of the mythbusters guys...
thats some cleverass work... u didnt wanna just order new motormounts online?

i had 2 motor mounts break on my last car.. one in half and one lightly cracked, pain in the ass to replace...like withthe engine installed and everything.

mustve been a while since you did that, hows it holding up?
 

·
Registered
Joined
·
1,433 Posts
Discussion Starter · #4 ·
Its held up great, i've put close to 30k on the mounts and at first they were stiff but i "broke them in" in one of my tranny swaps. After that they felt a lot better but still a little stiff which is great if you are running a high performance engine but not to comforting in aa stock engine. Another issue was that i didnt paint them right away and they began rusting. Yet again in one of my tranny swaps i cleaned them and treated them with a rust inhibitor and painted them with rubberized paint.





 

·
Registered
Joined
·
931 Posts
nice work dima!
 
1 - 5 of 5 Posts
Top