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-   Rotary Car Performance (https://www.rx7club.com/rotary-car-performance-77/)
-   -   Solid motor mounts (https://www.rx7club.com/rotary-car-performance-77/solid-motor-mounts-222404/)

Scalliwag Sep 9, 2003 10:45 PM

that was weird, it did not post my text I wrote.
Anyways look what I just made. They are 3" diameter/ 1.75" tall with a hole for a 10mm bolt to pass. These are for 2nd gens

http://scalliwag.com/mounts/DCP_2804.JPG

http://scalliwag.com/mounts/DCP_2805.JPG

http://scalliwag.com/mounts/DCP_2806.JPG

Scalliwag Sep 9, 2003 10:52 PM

This is nothing new but I have an idea I wondered about. In a race car the vibration is not a big deal. In a street car it is a little annoying to feel every little pulse in the motor.
The mount that goes most often and gets the most torque is the one that gets pulled up on. So if you used one solid and a stock mount if you could get a little of the best of both worlds. What do you guys think?

88fc3sw/HX83 Sep 9, 2003 10:54 PM

how much :D

suganuma Sep 9, 2003 11:05 PM

i was going to make some of these for my car, but wanted to test out some polyurethane ones first....the urethane is enough for me.

i MIGHT use delron, but i think solid aluminum is a little too far for a still sometimes street driven rx7...if, for no other reason, i'm afraid of shaking loose every nut, bolt, fastener, etc and i dont feel like even THINKING about switching to nylocks or safety wiring all of that shit....

diyman25 Sep 9, 2003 11:34 PM

cool. might want to get one for my ITE 2gen:p:

neevosh Sep 10, 2003 01:05 AM

I was gonna try and make some delrin mounts for my car. How exactly do you mount them, since the stock rubber mounts are one piece?

Rx7-AIII Sep 10, 2003 02:59 AM

Make sure you do the diff mounts as well or you will end up with a lot of force passing through the PPF which may then crack. The rotary is fairly smooth solid mounted.

Scalliwag Sep 10, 2003 07:22 AM


Originally posted by neevosh
I was gonna try and make some delrin mounts for my car. How exactly do you mount them, since the stock rubber mounts are one piece?
Just run a bolt straight through.

Scalliwag Sep 10, 2003 07:26 AM


Originally posted by Rx7-AIII
Make sure you do the diff mounts as well or you will end up with a lot of force passing through the PPF which may then crack. The rotary is fairly smooth solid mounted.
I figured there would be less wear on the tranny mounts since if the motor does not rock as much there would be less movement back there? But those would be easy enough to make I guess.

Scalliwag Sep 10, 2003 07:42 AM

Keep your eyes peeled for a urethane suspended mount I will be making. I have seen where people would take different soft materials and run a bolt through them. What they may not be figuring is that if you compress the bolt enough to secure it tightly the material will be compressed so tightly it becomes so dense that it is almost as hard as any solid mount.
If you don't compress it then the bolt will wobble and wear both itself and the holes in the mounts.
Anyway the urethane suspended will be two separate aluminum components. One goes into the other and has urethane at each end as well as the wall in between the two. These will be rebuildable but because of their design that all the urethane is encased and does not rely on it's bonding or even it's own material strength even service intervals would be many years in between.
You guys will see what I mean shortly. The design is more complex than a solid piece with a hole in it ;)

Scalliwag Sep 10, 2003 02:03 PM


Originally posted by 88fc3sw/HX83
how much :D
$50 a pair plus $5 shipping (continental U.S.) until shop orders are finalized. Then I have a "no compete" self imposed rule that will take effect.

rotaspec Sep 10, 2003 11:51 PM

I'd be interested in a couple at least. PM me when you have them available.

Scalliwag Sep 11, 2003 07:33 AM

They start shipping Monday. Three sets ordered as of today. I have enough material for 10 sets so in the event more orders than that come in, it will be Monday before I can get more material. So 7 more sets are available to leave Monday.
These were all ordered by forum people so they can give feedback on results.

93 R1 Sep 11, 2003 02:46 PM

Got any for a 3rd gen?

Resource Sep 11, 2003 08:47 PM

3rd gens?

now Sep 11, 2003 09:16 PM

Scalliwag if you take offense I will retract the offer.
I have made these before but never thought to offer
them for sale.
so if there is anyone "in canada" who wants these items
I would offer the same thing for 50 canadian.

matt

sub-zero Sep 12, 2003 12:25 AM

Matt, how about for a 3rd gen? I would take a set for sure.

Steve

Snufelupogus Sep 12, 2003 11:09 AM

I already have solid mounts... got a chunk of 3" steel dowel from the scrap bin at my school, chopped it in half, drilled some hole and I was good to go. Cost = $0 :D

now Sep 12, 2003 12:00 PM


Originally posted by Snufelupogus
I already have solid mounts... got a chunk of 3" steel dowel from the scrap bin at my school, chopped it in half, drilled some hole and I was good to go. Cost = $0 :D
i bet you added 30 or 40 lbs if you used steel:)

matt

Scalliwag Sep 12, 2003 12:33 PM


Originally posted by now
i bet you added 30 or 40 lbs if you used steel:)

matt

Haha!!! You know how many people may take that seriously? :eek:
Pretty much a lot of things can be used. Over the years I have seen wood, stacks of large fender washers, and stuff a lot less appealling than a steel dowel.
Pretty much if it works and is not going anywhere (like breaking) it is all good.
It all depends on if that works for you. I do suggest whatever you use has at least a 2" diameter for several reasons regarding stress that are pretty obvious.
I also recommend a minimum grade 5 but preferably grade 8 bolt to hold it.
The more balls you motor has and the harder you launch is the biggest contributing factor to what you will be able to get away with.
You can also lose (or not worry about installing) a engine torque brace because those are there for the residual flex that non-solid motor mounts create.
By the same token remember that all the force the non-solids absorbed is now going into the running gear.
So don't be surprised to find that the next weakest link in the system will be found sooner or later.
That is everything from the clutch to the differentials output shafts and everything in between.
So that new feel you get the first time you launch and you see the big difference may also cause your driveshaft to spit out from under the car.
On another note I saw a guy get hit in the ankles by a driveshaft standing next to a car doing a burn out.
Everytime I think of breaking driveline components I think of that. :eek:

Resource Sep 12, 2003 12:43 PM

3rd gen?

Scalliwag Sep 12, 2003 01:24 PM

I am picking up a 3rd gen mount bracket at Gotham when I stop by this evening to do a little metal work for them.
What I do know is that you would have to use your old mount brackets and remove the residual rubber. What I don't know yet is exactly what it will look like removed.
So I still have to see how the best way to mount to that would be. I am thinking that the hole where the rubber is molded through is close to 1". So I would want to turn (lathe) a locator at one end to align and stabilize it at that end of the mount. A little more machining if that is the case but no big deal at all.
I will post and take some pics tonight on 3rd gen.

88fc3sw/HX83 Sep 12, 2003 06:24 PM

I just Sent you some money via PayPal mike :)

Thanks,
Jim Kelly

Scalliwag Sep 12, 2003 07:15 PM

Thanks Jim.
The 3rd gen mount upon closer inspection does not have a hole where the rubber attaches to it. It will require being drilled. The good news is that I can just turn a relief onto the bottom of one end of the mounts to clear the "bump" on the bracket to make it sit flush and that will also act as a locator for centering.
Just wait for the pics and you will see what I am referring to.

KevinK2 Sep 12, 2003 10:38 PM


Originally posted by Rx7-AIII
Make sure you do the diff mounts as well or you will end up with a lot of force passing through the PPF which may then crack. The rotary is fairly smooth solid mounted.
Should be less torque through the PPF (FD) with front solid mounts. Max PPF torque would occur with super soft mounts front and back.


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