Motor mount cups? Do I need them?
 

Hi, I installed roadstertuner mounts last winter, and tested the car just few days ago. It was horrible, way too much rattle and noise for a streetcar. So I ordered "oem-style" comp mounts, but I have losen my engine mount cups!! Can I drive without them, what is their function?

Cheers in advance!

Nothing. You can run without them.

Not using the cups this time around. Might have some extra heat on the driver side but idc.

Hmm, I´m still figuring what is their meaning in the first place? Do I melt my turboside mount without this cup? I could weld those from 2mm steel plate if necessery...

I believe they are there as a backup to keep your motor (somewhat) in place. If your motor mounts are broken into two pieces, without the cup your motor would be able to move freely on that side but with the cup it keeps it (somewhat) located in the right spot.

Heat from the exhaust and they do space the engine out a good 1/8". No idea how important that is. For the 1 month I had a derlin mount I just used some washers for spacers.

They also I believe act like bump stops snubbing motor movement under extreem loads wheere the stock mount would deflect much further without them.

I kept my cups but drilled big 1" holes in them so I can see if the rubber is damaged and lighten them up a bit.

Tried AWR mounts and decided they were way too harsh for anything that saw street use.

Bob

Does somebody have extra mountcups around for measurements?? If I decide to do diy version of those. Mostly I´ll need the depth of the cups, if they work as bumpstops as bbundy said above.

Why not use the factory part? Nothing wrong with it.

But to answer OP's question, no you don't HAVE to use them, but there's no reason not to.

Because I lost them! :facepalm:

http://www.ebay.com/itm/MAZDA-MIATA-...8e2def&vxp=mtr

30 bucks on ebay?

they are also there for when you crash. they help keep the engine where it should be where the rubber would just tear. up to you if you run them but i do on the race car.

My cups aren't anywhere near the mount bracket, so I can't imagine them acting as a bump stop...

They do keep the mount from wandering off when they rip, and keep the motor sort of located in the car.

I´ll try to find them locally. Before that I´ll run without them... Thanks for replies!

I have mine out at the moment, I can measure them if anyone would like.

I don't run with them with the latest installation. I don't know if I'd run them necessarily.

The "safety" aspect I do not buy into - if you crash hard enough to rip the engine/drivetrain out of where they are braced/installed into, you've crashed hard enough to rip the rubber right out of the safety cup.

I think that it is there more in case you have a ripped motor mount and drive it. The RX7s have a similar motor mount setup, and it exists for the exact same purpose - it's there for if you are a normal driver, never check your motor mounts, and only take it as a measure of last resort to a mechanic.

Imagine the motor twisting about the crankshaft axis. The C shaped steel part of the engine side of the motor mount will bottom out on the cup if one of two scenarios happen.

1) The rubber part of the motor mount which connects the engine to the chassis fails completely
2) The rubber mount is over loaded and deforms too much.

With the cup in place the design of the system behaves both as a failsafe and an overload bump stop limiting motion.

Bob

https://www.miataturbo.net/attachmen...6&d=1335306516

We had a spec car have an off and touch a wall or armco. Minor body damage, but a ripped motor mount on the drivers side. I checked the car before that session and the mount was fine. The motor was leaning on the metal cup. Changed the mount in 15 minutes and all was good. Not sure what else would have been damaged without the cup.

If you want to get rid of them for weight savings, take a dump before jumping into the car and leave them be ;)

Can we add a poll to the thread? Or too many polls going around?

What do you need a poll for? You now know their function, just decide if the safety/function is important to you.