Due to my subframe swap I'm gonna have to get creative to mount my 12A (would be much easier with a 2nd gen 13B but the money just ain't there). So I have thought of doing a bar fromone frame rail to the other (just steel angle iron). I've seen solid motor mounts before for these cars, should I just mount solid to the bar and call it a day or will the vibrations be too much? This is mainly a fun car that gets driven relatively short distances although I do drive up to 1.5 hours at a time on the weekend. Any input would be great.
Grant

 

something will have to been done to either quell or circumvent the vibration issue. it will crack the front cover and i'm sure you can see why that's not a good thing ...

 

Hmm, yeah that seems like a bad thing alright. I know the FC guys run them, but then again they mount to the irons. Has anyone successfully mid-mounted a 12A like the FC motors? I may do the mount as I stated about but with a piece of solid rubber inbetween the mount off the engine and the bar on the frame.
Grant

 

no not really. what you can do is just use one solid mount on (either) left or right side, then one rubber mount on the other if you're picky w/ vibrations.
i do not think it will hurt the front cover

 

Well thing is, I can't use anything resembling the stock mounting arrangements because I've swapped an FC front subframe and it just can't accomodate them with the steering rack right there. So what I've come up with after a few failed attempts is to just weld a piece of steel angle-iron from one frame-rail to the other and hang the motor off of that. If I can get away with mounting it solid I will, otherwise I have to find some way of getting some rubber in there.
Grant

 

solid on both ends, but put some rubber in the middle. if it's done right, it shuld last a very a long time

 

I would be afraid of the front cover either cracking or the bolt holes in the cover wollering out. if anythings gonna give its gonna be the soft aluminum of the front cover. If you have a mounting system in mind you could go down to Auto Zone and look for an appropriate looking motor mount or two. If you were deealing with cast iron or something the solid mount thing would be a better idea I think.

 

well since this will be a fab-job, then you may consider using the front housing studs if you don't have air conditioning. if you do, then just try to incorporate some kind of solid rubber or polyurethane into your original idea.

maybe explore stock mounts for other cars?

just throwing ideas out there ...

 

I had considered using the AC mounting studs, the only problem is what to do on the exhaust side? I had even considered using the exhaust studs but that'll be a bitch for exahsut work in the future. I dunno, I may just try the solid mount as a temporary so I can at least move it under it's own power and see if the handling isn't completely screwed-up (which is a distinct posibility as things are now).
Grant

 

People are still spreading rumors of cracked front covers? I remember a long long time ago when I was making some delrin mounts and I heard a bunch of the "cracked front cover" talk, yet no one was ever able to pony up some pictures or even a story of it happening to someone they know - save for one story and pics of a smashed car. Do you honestly think Mazda didn't take the load characteristics into mind when they designed the mount? And as engineers go, they would have designed for well above what the engine could produce, maybe even what the moving car can produce, at say, 60mph.

There are more people now who run solid mounts than a few years back when I asked before, let's see if someone comes up with a story this time so that I can stop bitching about the rumor-mill effect of online forums.

 

i agree.

call a reputable shop and ask their opinion.

 

Judge Ito welded some aluminum to an FD front cover on his drag race RX-3 so it could take advantage of a front cover motor mount. I think his engine is solidly mounted.

 

Well I've got a spare front cover and a lot of testing time before this becomes anything like a daily driver so I think I'm just gonna go with it.
Grant

 

I had a bit of devine inspiration today while holding a piece of angle-iron. Looks like it'll be a semi-rigid mount with some rubber to absorb the vibration. Hopefully it works, I'll try to post pics of this badness once it's all done.
Grant