: Make Your Own Damn Motor Mount



kckranz
07-22-09, 03:17 PM
Now, several of you have worked hard developing a custom motor mount so I don't want to trivialize your efforts, but this article suggests you can make a half-decent mount yourself using basic tools and skills:

http://www.nicoclub.com/articles.php?id=215490

Tools:

- Wire brush
- Grinder or Dremel with cutting wheel

Materials:

- (2) plastic cups (the cheap kind)
- (1) 1-lb container of Flexane 94 (order online)
- (2) 4" 12x1.25 allthread rods (Ace Hardware has them)
- (4) motor mount nuts (or any other 12x1.25 nuts)
- (2) flat washers
- Brake parts cleaner

Procedure:

First of all, take your 2 pieces of allthread and thread the nuts and washer onto them, making sure they're centered on the rod like so:

http://www.nicoclub.com/Greg/gtlive25.jpg

Tighten the two bolts against each other with two wrenches. Then, take your grinding wheel or Dremel and cut some notches in the washers. Don't worry about neatness, you want them to be all jagged and nasty-looking:

http://www.nicoclub.com/Greg/gtlive26.jpg

http://www.nicoclub.com/Greg/gtlive27.jpg

Next, break out the cheap plastic cups. The size of cup will determine the diameter of your motor mount, so choose wisely. Or, just grab the cheapest crap they have.

http://www.nicoclub.com/Greg/gtlive28.jpg

Make a hole in the bottom center of each cup, slightly smaller than the allthread rod, and thread the rod through it from the inside:

http://www.nicoclub.com/Greg/gtlive31.jpg

http://www.nicoclub.com/Greg/gtlive32.jpg

Make a mark on the cup the height that you want the motor mount to be. You can see my marks in the pics above.

Find a "stand" to set the cups in, so the threaded rod can be suspended - I found that a spray paint can cap works perfect.

Now it's time to mix the Flexane. The main ingredient is clear, and the catalyst, or hardening agent, is black. Follow the directions on the label, it's approximately a 3:1 (Flexane to hardener) ratio. Mix ONLY the amount you need, because you can't save the mixed product. It hardens.

Once your mixing is done according to the instructions, pour the Flexane mixture into the cups. Try not to get it on the threads.

http://www.nicoclub.com/Greg/gtlive33.jpg

http://www.nicoclub.com/Greg/gtlive34.jpg



Now, find a warm place to set the concoction. It doesn't really stink, so if you live someplace cold, you can set it in the house.

It's best to let it sit 24 hours, or you can let it sit 12 hours and then put it in the oven at 150 degrees for 12 hours (which is what I did).

Once it cools, you can tear away the plastic cup. The finished product is cool, functional, and cheap.

http://www.nicoclub.com/Greg/gtlive35.jpg

http://www.nicoclub.com/Greg/gtlive36.jpg

http://www.nicoclub.com/Greg/gtlive37.jpg

Flexane has a resiliency somewhat near polyurethane, and you can experiment with different mixtures if you want it softer or harder. These should have great vibration dampening, while retaining the rigidity of a solid motor mount.

But they're clearly superior to the OEM mounts, as they won't oxidize (like rubber) or deteriorate (like rubber).

As far as strength, it has a hardness of 97A (Shore D scale) and a tensile strength of 2800 psi. Even at 400hp, these mounts won't see that kind of load.

As far as heat resistance, OEM mounts begin to degrade at 160 degrees F. I added to heat shielding to mine, but I can't imagine them seeing 180 degrees consistently.

At idle, it's a little rougher than the Nismo mounts were, but nowhere near as rough as solid mounts. The Flexane provides some nice (but firm) dampening.

This project cost a grand total of $56, if you count the $50 for the Flexane.

Raze
07-22-09, 04:05 PM
awesome

Bonneville GXP
07-22-09, 04:38 PM
Thanks for the info, I am going to try it, will let you guys know how it turns out.

68Futura
07-22-09, 05:26 PM
I like the idea, but i dont think you would really want to do this on a nice daily driver. I would think it would cause to much vibration

Ranger
07-22-09, 05:26 PM
Very interesting. I like these kind of projects. Definitely keep us updated.

Krashed989
07-22-09, 06:33 PM
With that design I don't see what the purpose of even putting rubber on it is for. It's technically a solid mount with no vibration dampening.

Raze
07-22-09, 08:52 PM
With that design I don't see what the purpose of even putting rubber on it is for. It's technically a solid mount with no vibration dampening.

That's not a solid mount...

Ranger
07-22-09, 08:56 PM
I don't see it as solid either.

Submariner409
07-22-09, 08:59 PM
With a pair of locknuts on top and on the bottom (not against the polymer), the engine rocks on the polymer cookie. Sort of a variation on the OEM liquid-damped arrangement. You punch it, the whole arrangement goes solid. Normal driving, the engine front rests on the cookie. BUT, more elegant would be a smooth hardened stud where the engine and frame mounts constantly rub, transitioning to the locknut threaded portion.........

Ranger
07-22-09, 09:16 PM
Ah, I see what you are saying Sub. It would need another polymer disc on the other side of the cradle to sandwich the cradle. That would be pretty easy to make with this process.

kckranz
07-23-09, 07:57 AM
Ah, I see what you are saying Sub. It would need another polymer disc on the other side of the cradle to sandwich the cradle. That would be pretty easy to make with this process.

I like where this is going and by the pictures it looks like there is enough polymer to make both (maybe more) cookies, though the write-up does not state this specifically.

STSS
07-23-09, 11:33 AM
What about cleaning and filling a ripped OEM mount with this stuff?

kckranz
07-23-09, 11:53 AM
The use of 3M Window Weld ($11) for that exact application has been documented elsewhere. I believe a 1 lb container of the Flexane is the smallest size you can buy so you might as well go ahead and make a new mount (or two!).

http://importnut.net/motormount.htm

Ranger
07-23-09, 11:58 AM
What about cleaning and filling a ripped OEM mount with this stuff?

Another good idea.

STSS
07-23-09, 12:31 PM
My current one is on its way out... maybe I'll give this a try... I've got some crazy strong epoxy I was going to use, but I am afraid it will be too hard and make it feel like a solid mount.

AJxtcman
07-24-09, 07:46 AM
Now, several of you have worked hard developing a custom motor mount so I don't want to trivialize your efforts, but this article suggests you can make a half-decent mount yourself using basic tools and skills:
http://www.nicoclub.com/Greg/gtlive37.jpg

As far as heat resistance, OEM mounts begin to degrade at 160 degrees F. I added to heat shielding to mine, but I can't imagine them seeing 180 degrees consistently.


The angle of the dangle look off

The New Deville style mount aka Seville mount
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/HPIM0382.jpg

The Original Deville mount that you can still purchase and last for years
http://i224.photobucket.com/albums/dd25/AJxtcman/Northstar/HPIM0378.jpg

As you can see the older mount has a steel top and is smaller in diameter. The Seville mount is bigger around and the rubber portion is at the top. This makes it closer to the exhaust manifold and that is why the shield came into play.

I would say 400 F is the air temp in that area. I have an EGT sensor mounted near the mount and it runs about 850 F in normal driving conditions.

smooththg6969
07-29-09, 05:06 PM
dude bless you I dont give a damn about minor vibrations im tired of the damn mount breaking.

codewize
07-29-09, 10:32 PM
That's not a solid mount. What I have is a solid mount.

I may just try this. But AJ is right. The angle is all wrong. The fastener orientation is not a straight line at all.

The vibration isn't that bad. It's there and at first it's noticeable but you soon forget all about it. I'm talking about a pure solid mount. I think AJ is working on some sore of hybrid that I can't wait to see.


With that design I don't see what the purpose of even putting rubber on it is for. It's technically a solid mount with no vibration dampening.

Krashed989
07-30-09, 03:48 PM
It is a solid mount when you press the gas pedal. Aside from the angle issue, I think it would be best to do what Sub mentioned and lengthen the lower stud to put another rubber bushing underneath the frame. When you sandwich the frame like that, you will not have a solid mount.

kckranz
07-30-09, 04:16 PM
I may just try this. But AJ is right. The angle is all wrong. The fastener orientation is not a straight line at all.


The mount pictured was not installed on a Cadillac. The write-up is from over in the Nico forum - I credited the author by citing the link in my original post. I posted the article to encourage others to experiment with different ideas. It seems we have all pinned our hopes on a few overworked members when the solution may be more of a DIY project than we imagined. I never knew the materials were available to consumers. I am neither a physicist nor a metallurgist so I cannot guarantee success - I am merely passing the information along.

Ranger
07-30-09, 09:39 PM
Might consider making a set of torque struts like I did to restrict engine movement and thus save the OEM mount.

Submariner409
07-30-09, 09:49 PM
IIRC there was a post last fall concerning a very clean torque strut installation which was incorporated into the strut tower brace............

Ranger
07-30-09, 10:07 PM
Yup. That was FAR more elaborate than mine and a real piece of art to boot. That won't work on the 2000+. They lost too much real estate under the hood. :mad:

codewize
07-31-09, 12:13 AM
I would say. Some of you may remember me trying to add a strut brace to my DTS? Not happening. Just no room.

Ranger
07-31-09, 10:05 AM
Sure there is. Didn't you see this?
http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/175113-fabricated-torque-strut-2000-norhtstar.html

kckranz
08-01-09, 07:48 AM
Might consider making a set of torque struts like I did to restrict engine movement and thus save the OEM mount.

I'm probably going to try this though I worry about the added pressures to the head. It has its own obstacles.

Ranger
08-01-09, 10:28 AM
That is where the torque struts where mounted from the factory on the pre 2000's so there shouldn't be a problem. Otherwise see Subs idea. That has a lot of merit.

codewize
08-01-09, 12:59 PM
No I didn't see that. I was talking about a strut tower brace when I said that BUT, Those don't constitute struts as they're rigid. I don't think rigid is what we want there.


Sure there is. Didn't you see this?
http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/175113-fabricated-torque-strut-2000-norhtstar.html

Ranger
08-01-09, 03:11 PM
Why not? What's wrong with rigid. You want to keep the engine from torquing, don't you? Other than the rubber bushing, the factory struts (dog bones) where rigid.

Submariner409
08-01-09, 06:32 PM
BUT, the fabricated strut tower brace/dog bone arrangement and the OEM dog bones (engine torque struts) had elastic mountings, very similar to suspension arm bushings.

A cable or chain snubber will go solid at 1/2" of engine rotation (if made correctly). Who cares about V8 vibration for 15 seconds of WOT ?? Especially if you're not twisting and bending the motor mounts and every piece of hose, pipe, and wire connected to the drivetrain ???

Ranger
08-01-09, 09:11 PM
The only thing elastic that I recall on the OEM torque struts was the rubber bushing. What I don't understand is why anyone is concerned about holding it down so there is little to no movement. Isn't that what is killing the front mount? Isn't that what we are looking for? Seems to me the less we have the better. The engine is still mounted on rubber. I've just curtailed the torque under load.

I agree that there is no room for a strut tower brace, but that is another story. We are talking about motor mounts and holding the engine down (I think). Unless you (Code) where talking about the strut tower torque brace that Sub mentioned.

codewize
08-01-09, 09:25 PM
Sorry Ranger, I got off on a tangent. OK Back to strut braces. Yeah I guess we want to hold the engine in place. That is the idea but so rigidly? Maybe, I'm not an engineer, although some may argue that point.

Just seems a little, umm, tight? I don't know, maybe I'm wrong.

Ranger
08-01-09, 09:37 PM
Well, let me ask what you think is wrong with rigidity in the torque strut? While some movement may not hurt, I can't see where any at all is beneficial and the more you can get out of it the better to my way of thinking.

codewize
08-02-09, 09:08 AM
OK, maybe a view from a different angle? Is the thing we're strapping it to, up to the task of holding it back? I can envision that rad support being ripped out of the car over time.

Ranger
08-02-09, 04:39 PM
I think it is. That's where the OEM struts where mounted to before they did away with them.