Do you need urethane motor mounts? Here is DIY

[Grubby]

I have had two ERAs and seen others that the headers contact the body (lightly). I tried the ERA bolt limiter and adjusting the engine around to no success.

I knew there was a better way. This is it.

I decided to put polyurethane motor mounts in, but you can't buy them for this application. I think the mounts are 63-64 Ford big car.

Here are a few pictures and the quick how to;

1. Make a mold off a rubber mount. Some clay was needed on the bottom to let me get a good straight line to create the mold





2. Pull the rubber out and clean up the steal halfs. Some heat required.





3. Load the steal halfs into the mold. Plan and drill a hole into the mold to pour the urethane and use grease or something similar for a mold release. This mold was one time use since the mounts are handed. I even glued the part lines to minimize leaks (lesson learned on the first mount)





4. In order to keep the urethane from running out I poured about 1/2" of plaster paris on each side of my mold that contained the steel halfs.







5. Mix and pour in the urethane. Let it dry for about 48 hours and then gently break the mold away. The result looks just like the rubber mount, but has a hardness rating of 80 Shore. 7 days total dry time is required.







I have about $150 in both mounts. The Polyurethane came from Energy Suspension (2 cans needed) DST DIYMMI Do It Yourself Motor Mount Inserts - Liquid Urethane Made by DST (Mcmaster carr has the same material in larger containers)

The clay came from Walmart and the plaster paris from a local craft store.

I would use fiberglass or urethane to make the molds if I was doing a quantity, but for one off the plaster paris works well.

John

[rodneym]

Nice job!
Didn't know there wasn't any PU FE mounts.
Consider doing a run of about 5-10. Some of us may like the idea but not enough to DIY.
I assume the PU is really stuck to the steel?

[Detroit Bill]

Olthoff has mounts not sure if they would work in your application

Motor Mounts - Olthoff Racing

[patrickt]

Well that was one heckuva project! You know I like anything that includes pics like that. Very nice. Of course, you could of always just bolted on a torque strap....

[kevins2]

Originally Posted by patrickt

... Of course, you could of always just bolted on a torque strap....

I think that's what the ERA bolt limiter is that he referred to. Still, a pretty good project.

[1795]

Nice job John, reminds me of making molds in junior high school. They should work well. Dennis Olthoff is the only other person that I am aware of who makes polyurethane motor mounts. This is definitely a thread to hold on to.

[Grubby]

I don't think the Oltoff mounts are the right part for an ERA. Not all FE mounts are the same.

The ERA limit bolt certainly helps, but I suspect the bigger problem is the Right mount compresses during hard accel and allows the Left header to come up. During engine braking you would have the opposite problem. I have seen contact marks on enough cars to convince me it is a problem, and I couldn't resolve mine completely.

I did put the ERA limit bolt in the LH and RH mounts.

The urethane sticks like crazy. The OEM mounts are essentially made the same way, but the "rubber" is much softer.

Rodney - I would consider doing a run of mounts. 10 pairs would likely be enough to make this a cost effective project. That would be enough to justify a more permanent mold that could sit on the shelf and be pulled out as needed.

John

[Grubby]

The motor mounts for ERA cars are =
63-64 Ford w/390-428 cid, Ford C3AZ-6038A,B
Republic 31-2222 (right), 31-2223 (left)

John

[sea2jet]

I would be in for a set if you decide to do a run. Mike

[davids2toys]

I would consider these also.

[1795]

Let us know what you think a set would cost. Not having any issues now, but you never know.

[Chaplin]

I'd be interested in a set as well.

[Grubby]

All,

If we can get interest in 8 pairs, I will do it for $200 a pair. If you want to supply your own motor mount cores it would be $30 less. More interest would push the cost down.

That would be enough pieces to justify a good quality mold.

Once the mold is made I could produce a pair every 48 hours. The mold may take a few weeks to design and build.

If you have something other than an ERA, you are one your own to determine if these are the correct mounts.

John

[DanEC]

Anyone want to venture a guess as to if there will be any noticeable change in engine vibration/noise with these?

I'm weighing whether I really need these with my undercar exhaust. But, the exhaust system is pretty rigidly mounted and doesn't need a lot of engine rocking to work on it. And I do worry about air cleaner contact when the motor torques over - so possibly.

[Grubby]

Dan,

People with performance cars have used urethane for years. It just wasn't a viable option because of the OEM application for our mounts.

Urethane can be purchased in 3 hardnesses for this type of job. The 80 that I used is typical of a urethane mount you would buy from the various companies for high performance street use. You can get about 96 shore for racing applications. And you can buy a urethane that is roughly the same as the OEM rubber.

No doubt these will transmit more vibration into the cockpit. I would expect much less engine movement.

I will purchase a urethane trans mount from Summit or others to go with the engine mounts.

John

[sea2jet]

Count me in if you decide to proceed. Just let me know when you want the funds to be sent. Thanks.

[Grubby]

Status;

I have gotten a few contacts off line as well as the ones in the thread. It looks like 3 maybes and 3 interested.

Could all that want a set, send me a PM to grubbs@tds.net. That will let me get a better count.

If the numbers are enough to go, then I would ask for a small earnest deposit of $20 or send me a pair of mounts.

I am proposing that for $200 I will get a new set of rubber mounts; disassemble and make them into 80 shore urethane mounts; paint the metal surfaces with gloss black Rustoleum and optionally drill the hole for the ERA bolt limiter. If you don't want the hole, I won't drill it. Or if you want it in only the Left mount, I can do that. You supply the bolts and nuts.

If you supply a pair of used mounts that aren't too rusty, I will do the same for $170.

Plus actual shipping to you. No cost to package or anything like that.

Please note I have a full time, professional job that sometimes requires extra hours or travel. I'm just a Cobra enthusiast like you. Getting the molds right could take some time.

John

[davids2toys]

Originally Posted by DanEC

Anyone want to venture a guess as to if there will be any noticeable change in engine vibration/noise with these?

I'm weighing whether I really need these with my under-car exhaust. But, the exhaust system is pretty rigidly mounted and doesn't need a lot of engine rocking to work on it. And I do worry about air cleaner contact when the motor torques over - so possibly.

OK, I will guess. I think you will have more engine vibration in the cockpit. I don't know if you will have more or less car movement though. I have the stock setup with the limiter bolt and my car moves right along with the cam. I actually love that , just like my Harley. I would not call that a vibration though! That to me is just old school HOT ROD, cam duration rock and roll.
On my bike the motor mount is adjustable, it actually has a Torque range, anything tighter then the lower end of the range and the bike had a very unfriendly buzz or vibration. At the lowest torque, it is beautiful. I think this may relate to this situation.
As far as the air cleaner hitting, I would say you have nothing to worry about and that is coming from a very scary experience I had with my car after only owing it for a week. I will cut to the chase and just give you the jist of the story and spare all the details. I nailed it in first gear going up my long steep driveway. I was used to doing this all the time with my first Cobra. The gas pedal stuck right to the floor. It was my lucky day though because I ended only having minimum damage to my car and I am still alive to talk about it. I will leave it at that to keep it short. So after all the troubleshooting, my driver's side motor mount was completely loose. So between all the Torque of the FE, being in first gear, the very steep pitch of my driveway and the loose motor mount. The motor Torqued over locking up all the throttle linkage in the full open position...YIKES!!!
So, my point is that no contact was made air cleaner or turkey pan to the hood in an extreme Torque over situation. I don't know your setup. I have dual plane manifold, Holley 750, 9"K&N breathable top air cleaner 2" high with a wing nut hold-down. Now there is no chrome cover on this air cleaner because of the breathable top, so it is possible that it might have hit the hood and not done any visible damage.
I know you are not worried about the side pipe damage because of your under-car exhaust, but for everybody else it matters. I do have the damage to both the openings for the side pipes in the fenders. I have seen this on many ERA cars while I was shopping for my car. It was on my car too, but mine definitely got a little worse after the accident though. A tribute to the ERA quality of the body is that there are no cracks! Easily smoothed and touched up. Not really noticeable at all, part of the patina of a driven car as far as I am concerned...but that is just me.
These motor mounts sound good as long as I do not get that awful buzz vibration.

[DanEC]

Thanks for the input. Think I'll pass for now and hope that John gets 8 interested parties for his production run.

[davids2toys]

I'm with you Dan, I am still on the fence. If they are going to transfer a bunch of vibration(buzz), I want no part of it, I will just do what Patrick suggested and get a Torque strap or chain as a safety just in case. The limiter bolt should do the job of limiting engine Torque over in a healthy motor mount, and the strap or chain will do the job if the mount actually breaks.
I have had cars in my younger days with SOLID motor mounts. They do have their place at the track but for a car I am going to spend hours driving, that would get old real quick.
Can't speak of urethane mounts because I never had them. I am going to guess somewhere in the middle of stock and solids as far as vibration is concerned.
Patrick, by any chance, do you have a link for those Torque straps?
Dave