I'm probably going to redo the other motor mount, I'm not completely happy with it.....
Ran out of welding wire, I usually just buy it from Harbor Freight, but they didn't have any of the 2 lb .023 spools I usually buy, nor did I see any of the 11lb spools either. I asked at the desk and they found a lone 11 lb spool " in back" that I think had been on the shelf a long time, based on the amount of dust on it, so they gave me 20% off. It's .025 which actually worked a little better on this 1/4" thick metal, but we'll see how it does on the thin sheet metal.
Next I need to find where I put my extra tips as this one is toast......I just saw them the other day but could not find them tonight.....naturally!
I bought a package at HF, but they don't fit this welder at all.
I borrowed a Miata axle from Jesse Prather Racing as he races Miatas, so once I finish the motor mounts and I'm sure of the engine position then I can pop the outer one in the hub and measure the short axle's length, then with that info they can get started on mine - I'm guessing it will take them a couple of months so the sooner I can get them moving the better. The company I bought the subframe from included the axles as part of the deal but they can't make them for me till I can get them accurate measurements.
I'm going to send them the short Ford axles, there should be enough length that they might be able to just cut them off and machine the one end to match the Miata CV joint, that way they only have to do one end instead of two, or if they want to start from scratch they'll have the Ford end to copy.
I was at Kent Prather's shop last night and we talked about how to change the studs in the front Mini hubs, it's going to be a bit more complicated than just drilling the holes bigger. Turns out the Mini studs have a taper around then to fit a taper in the hub - I've never paid any attention to them before so I didn't know they were made like this..... anyway Kent says the right way to do it is to send it to a machine shop.....have the spacing indicated, then set up on a CNC to make sure the holes are centered and spaced properly. He said the last time he did a set of hubs for an MG he did them on his mill and they vibrated like crazy, so he did this and it fixed the issue. I was just going to drill them and poke them in.....
Gearbox end motor mount designed and cut, just need to weld it up.
FWIW, I was told that .023 and .025 are kind of the same product except for some esoteric difference that plebes like us probably wouldn't ever care about. It's all .6mm wire as far as the welder cares.
This after I had a minor snitfit driving all over trying to find .023 wire and all I could find was .025...
Yeah, it all burns pretty much the same! 
Should get my hubs back from the machine shop on Monday, then I can go ahead and assemble the front suspension.
I thought about going with even heavier material, but in the end I decided to just go with what I already had built, and after getting it all welded up I think it's going to be plenty strong enough.
I reinforced the mount on the other end by cutting some legs for the angle iron and filled in the gaps on the mount, it feels a lot stronger now too. It fits, but barely - but it does clear and I don't expect it to move around much if at all.
I also cut the plates to mount to the frame. Now I need to cut out the parts to connect the plates to the mount and weld them all up.
Once that's done the next order of business is to engineer the engine steady mount. I have some ideas on how to do that and I may copy those used on Minis but I'll have to make it a bunch stronger, and adjustable.
With that done and the engine firmly mounted in the frame I can accurately measure the axles and get those started at the machine shop - who knows how long that will take to get made?
Next I'll put the front end together - once my front hubs are back - then cut out the hole in the back and mount the subframe (sans engine) in the back of the car. At that point it will at least be on its wheels and I can see if any of this stuff is going to work!
Drove about an hour and a half to the machine shop in the middle of nowhere Kansas (well, about 5 miles west of Burlingame) to pick up my front hubs. I sent them there because I wanted to use bigger (thicker) studs like on the rear and Kent told me if I didn't have a machine shop indicate them and bore them on the CNC mill the front end would shake. OK.....
So he bored the holes as instructed, but didn't machine the boss for clearance around the head of the stud.....I was resigned to the idea that I would have to have that done either at Kent's or a local machine shop, but it turned out he was there (they had left the parts in the outer office in case I came when they were not in the shop). I showed him what I wanted and in 5 min they were done!
He runs a really top notch clean as a pin huge shop in which they build front engined drag cars - big supercharged Hemi motors and all! They build pretty much every part in house, too.
I would love to use him for all sorts of stuff as his price was very reasonable and his workmanship is first rate, but he's just so far out there...... but what a place. Every kind of machine you can think of and some you can't - or at least some I didn't recognize, and the place was immaculate.
Custom Dragster Chassis & Engine Components - Neil & Parks Racing Enterprises
So, now I have everything I need to build up the front end, so that's next.
But first I finished up most of the motor mounts today - the engine end motor mount is all welded up and bolted in, and I got a pretty good start on the engine steady.....it's a little crude looking at this point but it will do the job I'm pretty sure. The last bits I need to make are the brackets I'll weld to the frame. There is a pretty large rubber bush I need to press in the frame end of the steady, then drill some holes in the brackets for the thru bolt to go thru, weld the brackets on and that's it.
With that done I'll get the final measurements for the axle lengths and see about getting them made. I sent a note off to the machine shop in Burlingame on Thursday to see about having them make them for me, but I may not hear back from them till after the holidays. I was kinda hoping to take the axles up to them before Xmas so that I could move a little further up the line, but it's not a critical thing at this point.
Still waiting on my fully adjustable coil over shocks, and my new turbo outer CV joints. I'm sure there's a little more fettling I'll need to do on the motor mounts yet, then maybe I can get some paint on them.
Prior experience with breaking motor mounts suggests the trans mount will need a plate along the backside so it doesn't parallelogram and fail. There's going to be a lot of force working against it if you get traction.
You don't think the cross piece I welded in there will do the trick?
Since everything I've done is bolt in, if I have to remake something it's do-able.
Today I finished the brackets for the engine steady..... I have the frame all marked up where I need to weld them but I may not get to that today. I also did some additional welds and clean up on the engine end, so it looks a little more presentable now - although I did that after I took these pics.
I also found the missing 2 wheel studs - Clancy had them - and got them pressed into the front hubs, so that's done and I can start building the front end once these brackets are welded on.
In reply to MiniDave :
I mean... worst thing that can happen is that it'll bend and you get to make Mk2 mount.
It IS probably better to have the motor mounts on the same plane than to make the bracket shorter, but there's always a tradeoff.
I keep looking at that 3/8" bolt on the engine steady and wishing I'd done it 1/2" instead, but I didn't have any 1/2" bungs. Now I wonder if there's enough meat in the bung I used to drill and tap it for a 1/2" bolt? I originally put it in there in case I needed to adjust the length on the steady, but now that I have it all made I kinda know the length. My OCD might kick in here and make me remake it......
I'm also looking at those two pads already welded on the frame and wondering if I can use those somehow for a rear sway bar....
More as it happens.....
The tensile strength of a grade 8 3/8" bolt is 11,625 lbs and shear strength is 6,975 lbs .... according to Google
3/8 will be plenty, most cars use about that size.
The thing with shear strength is that will tell you what the bolt can handle if it's loose. If it's tight, then effectively the sleeve and the bracket become one piece and the weak link is the bracket, not the bolt.
But let's say that it is 1.5 feet from the motor mount axis. Let's also say that the engine can make 250 ft-lb of torque, times say 3.5 first gear and 4.0 final drive. That's 3500 ft-lb of torque on the axles, so maybe 2150 pounds of force max on the torque arm, plus a little extra from shock loading that'd probably break the tires loose first anyway... You're fine. The tube will bend long before the bolt will fail.
OK, since it's easy enough to get to I'll leave it for now and carry on with other parts of the build.
Thanks for the input guys!
