I'm having some solid motor mounts made, was wondering if anyone was interested in jumping on board. Faster throttle response and the engine becomes a stressed member of the chassis.

Mounts will be made of 4160 steel and will be a bolt in replacement for your cushy rubber mounts. Cost will be about $50 for the pair.

 

The RB Engine brace made my engine pretty much solid.
and its adjustable to how much "Solid" feel you like.

 

Won't that crack your front cover?

 

that doesnt seem like to good of a idea for racers, the torque brace would do the same thing and allow some movement. imo all it would do is transfer the forces right to the front cover and cracko

 

It's possible.

 

Just run a $2 cable from the top of the front side housing to the left strut tower... that way the engine isn't a stressed member and you don't have a ton of vibration, yet the engine doesn't rock over under acceleration.

 

If I don't like the vibration I might try something with a heim joint attached to the rear housing and a solid mount on the firewall.

 

run a wire from the front housing to the strut tower? how do you attach it to the housing? weld a bolt on there? and how much slack do you leave, and why the left strut tower? is that the direction it likes to tweak?

 

You get the length of cable and two cable clamps so you can make cable eyes at each end. I used the front lift eye bolt for the engine side connection, made the cable too short to attach to one of the strut bolts, then pulled on the engine with my left hand and slipped the cable over the strut with my right. After a week or two it stretched so I had to take up the slack with a cheapo "emergency E-brake cable tensioner". I also slit a long vacuum hose and slid it over the cable, just because it ran close to the coil towers. (custom ignition)
And it made a big difference... no more engine bouncing around after a hard shift.
You attach it to the left side because you can't push on a rope

 

Ah, ok...
So this whole engine bouncing stuff... this doesn't happen much to mine... 12A-Automatic... hmmm...

 

So no one wants some solid mounts?

 

Being a completely untrusting soul in todays "Ya gotta look out fer number one, man..." world, due in part to my pesimistic nature combined with my disgust for todays' youth and their lack of marals and respect; and just being a general ****-all bitter person upon leaving the warm, wet, silent, dark sanctity of mine mothers womb, I gotta say that this is so obviously...

a scam!

What ******* machine shop is charging you 50 bucks for some steel hockey pucks?! And what machine shop did'nt tell you that the more you order the lower the price...Had you looked into it.
Of course you did. And of course they did. And so the opportunity presented itself to you.

And "4160" steel...for what?
A knowledgeable racer would've offered them to everyone in one of the nearly 40 applicable plastics that are available, easy to machine, extremely durable, non-deteriorating, and very much lighter than a giant chunk of steel.

Absolutely NO info about you in your profile.
Hmmmmm....Sure - I'll mail ya a check, dude.

Now please tell me I'm wrong, and then I'll appologize.

 

I think Sterling meant to say use Delrin plastic and use a reputable shop. And I think he is right.

 

In Nimrod's defense - he does have over 240 posts at this time.
I've never noticed him trying to sell anything (I notice that)
There are no requirements to your profile, I can understand and respect that decision, people can use all your information against you. I don't see him as a scammer, as it is, - everything on the internet is Buyer Beware.

Also, The Steel engine mounts were very popular when I used to Street race back in the day. It was overkill for anything but a bridgeport, or full blown drag racer though.

Giving him (and everyone here) the benefit of the doubt, it's probably the shop that is either still in the V8 mentality OR stuck in a Rotary Time Capsule.

 

O.K.
Sorry, Nimrod. My bad.
I'm still ****-all bitter about having to leave the womb, though.
Well...I guess it's not really your fault.

Please accept.

 

Solid motor mounts from 7075 T-6 Billet Aluminum.
Comes with nuts and bolts.
RX7 79 thru 85 part#1043
71-85 RX2-X3-X7 SOLID BILLET ALUMINUM ENGINE MOUNTS
(NOT FOR STREET USE). $69.99

http://www.mazdacomp.com/

 

No problem. Delrin, eh? I hold my order and look into that. As for the machining, my father owns a machine shop and gave me an estimate on parts cost with a severly cutback labor rate, and I chose the 4160 because he just happens to have some at his shop. I'll see if he has some aluminum because I'm pretty sure he doesn't deal with plastics.

 

Ok, checked into it, gonna get some delrin ones put together. Getting the estimate in a couple days. I'm just gonna do a run of four mounts, I'll test 'em out and take some pictures, then see if its worth my time to sell a few pairs.

 

Nim, the stock mount appears to be just a puck to isolate and support the engine. I think the delrin would work if there is no side to side (fore aft) movement of the drivetrain. You may wan to sleeve the Delrin like a control arm bushing is. Delrin machines easily. The pass through bolt should be very very strong.

 

Why would you think the stud needs to be so strong?

 

It will have to absorb all of the shock and vibration.

Regular motor mounts have give to them, so the bolts don't see high shock loads or heavy vibration working against them... the rubber damps that out.

That's why I'm against the idea of solid motor mounts, because SOMETHING will have to give, and I'd rather that it be a squishy motor mount than the somewhat flimsy front cover. To control the torque-over I just made the tension strap described above, similar to V8/GN drag racer guys who chain the left side of their engine to the frame.

 

HAHAHAHAHAAA, I remember helping my nieghbor do that Fucken STRONG *** motor...... It was funny to see the left side try to lift when ever he would rev it, or run it hard....... I think it pretty much twisted the frame, instead of it goin to the ground.... Oh well.....


LATERZ

 

What about polyurethane engine mounts?

 

I just had a ride in a 1st gen RX-7 with solid motor mounts in it. And I am ******* telling you right now it is now bad at all. There is almost zero vibration. The shitty mounts in my Mekur XR4ti are worse than a Solid Motor Mount equipped car. At 8000rpm there isnt any more vibration that at 3000rpm. And the funny thing is, i was just asking wether or not the car had them installed out of curiosity, I was expecting a no. And than he says yeah. I was amazed. It was smooth and it wasnt rough AT ALL. SO PLEASE PUT THIS TO REST. A SOLID MOTOR MOUNT EQUIPPED 12A DOES NOT DO ANY HARM!!!!!

 

That's funny, I pretty much forgot all about this project. I never did it, but I guess it's going back on the to-do list now. Maybe I'll just replace the rubber in the originals with some welded in mild steel instead of all the overly ambitious plans I had before.