evilmiata

Filled them. Recommend them. Here's what happened.

I was sick of ripping through engine mounts and didn't need the extra clearance that the Mazsport solid units provide. My car sounded like a jack brake when idling so I pulled the right/passenger/exhaust mount and cut it up.

The first thing I noticed was that there is a rubber membrane on the bottom of the mount. Its REALLY thin and can easily push the fluid around behind it. What really surprised me was how easily I could make this membrane bow out by pushing on the top of the mount with two fingers. How is this supposed to support a twisting engine? Totally idiotic design!

First thing I did was razorblade the soft rubber membrane off. Behind I found what looked like a cast iron baffle. I tried for 15 unsuccessful minutes to shake/swish/drain the fluid out. Obviously the baffling inside was pretty complicated, so I decided to find my good drill bits and cut some holes in the iron.

But this iron is plastic! Freakin' plastic in an engine mount! I guess plastics have come a long way since "The Graduate" but it was no match for my drill and a prying screwdriver.

So I get most of this plastic out and STILL here fluid sloshing around. Turns out there's a second, smaller membrane behind the plastic baffle. WTF? I attacked the soft rubber and gutted as much of the whole mount as possible.

At Rotary God's suggestion, I ordered a pound of 80a shore (it gives about as much as a thick tire tread when cured) urethane (this stuff is so cool!) from McMaster. I mixed it up and poured the mount halfway full and rocked it back and forth to make sure I got rid of all the air pockets. Satisfied that all the bubbles were gone, I filled the mount to the brim and let it sit for two days.

I've got about 50 miles on them now and the idle is sooooo much better. It does seem to shake a bit more at 800rpm, but that could just be me used to driving my 626 around for the past couple of weeks. I'll have to sit in someone else's car to really see if there's a difference.

I've got my manifold and downpipe (top mounted GT35R) just 2 inches from the mount, so there's probably a lot of heat down there. The OSHA (or whatever that paper was in the box) sheet says the urethane is good to 600*. But if you Greddy guys are having mount problems, I think this will be your $26 solution.

I didn't do the driver side mount.

The fluid inside the mount looks like oil, but washes away easily with water.

I've got pics but I'm on the road and my laptop doesn't have a memory stick slot (damn Sony!). I'll get some posted tonight.

gh0st

cant wait for the pics man

evilmiata

The rubber membrane cut away. I was sure this stuff was metal!



It ended up drilling really easily. You can see the second fluid chamber in the center. I've attacked it with the drill and needle nose pliers.



A macro of the baffles. I count 3 and suspect a 4th below.



Here's the final product. It can't be seen in this pic, but I also let some urethane leech between the mounting bracket and the round cylinder. They're both metal and appeared to be pressed together so I figured why not. The urethane was quickly wicked up and rose to the brim without any leaks. I was surprised how much I could get to seep in there!



I logged just over 130 miles today with these installed. No complaints. I also sat in Mantis of Mazsport's car (stock mounts) to compare the idle quality and vibration; they're the same. My last set lasted about 1700 miles. I'm hesitant to say mission 100% accomplished until I reach that marker, but I think I''ve got it this time.

RX8Maine

How hard is it to get these off in a garage with no lift? Can this mount be looked at without supporting the engine? I have a vibration at idle (less than any other car I've owned, but I feel it in my *** . . . apparently that's a no-no for rotaries, so I am seearching for a solution.) Hate dealerships.

evilmiata

There is a vibration at idle. The noise I'm complaining about is a loud, metal-on-metal, embarassing, '79 Monte Carlo, "Look at that beater, Mommy!" vibration.

I used two jacks and a 14mm deep socket. One jack under the rail and one under the oil pan. I do have the cast Greddy pan, so I don't know how well the stock sheet metal pan would hold up. You only need to jack up one side of the motor, though.

MazdaManiac

iTrader: (3)

RG, eh?
I posted about this in February!
https://www.rx8club.com/showpost.php...80&postcount=5

I had a DIY under my old screen name (maniac) back in '04, but Ryan deleted it when he went on his rampage.

I too have only done the passenger-side.
I have an extra driver-side mount, but I haven't had the desire to pull it lately.

evilmiata

Doh! Sorry! You guys post so much good stuff that your names blend together. Props to MazdaManiac.

nycgps

iTrader: (1)

Im very interested in this DIY, They replaced my Engine mount about 6 months ago. Cuz it shakes so bad at Idle that I feel sorry about myself. The *shake* was gone after they replaced the mount ... well I was happy for about 4 months ? Its coming back and I Think its shaking worst and worst now ....

Hmm. Where did you get your urethane from ? which store ?

Sounds like an easy DIY .... How long did it took you ? I've never had any experience in this and Im just afraid that I might mess something up

rotarygod

I was surprised to see my name mentioned. I didn't remember recommending that. I was wondering why I didn't remember that. Now I know.

MazdaManiac

iTrader: (3)

Were blending together, Fred!
Attack of the Evil Rotary Protoplasmic Blob!

california style

you WILL be assimilated!

evilmiata

It takes 5 minutes to jack up the car & engine and remove the mount. The most labor-intensive aspect was beating the hell out of the plastic baffle. I had at least 30 minutes of work time @75* (its the first day of winter and I'm sweating my *** off tonight!) but I was done in pouring in a couple. I got the urethane from McMaster.com . They have a really stupid gimmick of not allowing links to their website so go to the main page and search for 8644k11. This will give you 16 ounces of urethane which is plenty for both mounts if you can suspend the motor.

Let it cure for 2 days. I'm the HOA president and we're not allowed to work on cars outside. I had the right side of my car jacked up for 2 days but tried to hide the jacks by closely parking our other cars.