Mini Ecoboost Project

So MiniTec called me back and after a good conversation I now know what to get parts-wise to keep moving forward.

Don dropped by and helped me lift the subframe up and off the engine so I could get it up on my lift table and get started cutting off that boss to make clearance for the suspension arms to move.



Once up on the table it wasn't too hard to cut the boss off and use my angle grinder to clean up the area enough to do a test fit. Putting the subframe back in place by myself turned into a challenge, but using the engine lift and some straps and chains I managed to get it in place.

Now the axles line up nicely and there's room on both ends for the trailing arms to move without hitting anything.





I messaged my brother in England who used to work for Sanden to ask about compressors as I won't be able to use this one now that I'm using the area where it used to mount for the suspension.....he gave me a couple of leads as it's now going to turn the opposite direction - on what compressor to order and it turns out they're readily available and fairly inexpensive. Once I build the motor mounts, add the coilovers and axles, I'll be able to see where exactly I can put it and build some brackets to mount it.

I know on some of the Vtec Mini builds they mount the alternator to the frame rather than the motor - not sure that would work but it's an interesting thought anyway....I'd be concerned with vibration when it's running and how to tension the belt.

1st pic shows where I cut off the boss, second the clearance to the trailing arm and third the nice straight axle lineup.

While I had the subframe standing on its side I also found where the adjustment is for camber, it uses a large eccentric washer to move it where you want it.....simple and effective. A similar set up adjusts toe....

All of the aluminum has a lot of corrosion on it, I found some liquid spray-on stuff that's supposed to clean the corrosion off without damaging the metal......that will be one of the last jobs I do, but I'm definitely going to give it a good shot at cleaning it off. Maybe while the engine's out when the body is at paint would be a good time to tackle that......

 

Trying to sort out how to do the motor mounts, MiniTec sent me a pair of what they use. The transmichigan end is easy - lots of room. The other end is close! I cut a length of 1 1/2" angle and mounted it to see how I can do this - it's possible - it just fits in the gap, but it is tight!





I also ran the suspension to both extremes and everything clears with ease, so no worries there.

 

I'm having fun with it, and considering I don't have any machine tools everything is pretty crude, but as long as it functions it will have to do......case in point......

After finagling the motor around in the frame a bit, I welded up the motor mount on the engine side, but ran out of back and material to finish it. Next I'll build the legs that attach it to the subframe, then switch over to the transmission end. I also need to buy some bolts and some more metal for the "legs" on both ends, plus I want to brace up the shell before I start cutting any metal out of it - it's probably only held together with the paint as it is!

This is my first effort and I'm sure I could do better, but as long as it holds, the only one who will ever see it is me!





I had a weird thing happen when I was trying to weld it up - I was just putting a couple of tacks in to see if I had the angle and spacing right, and it just would not weld. I was using a couple of very strong magnets to hold things in place, so I switched over to regular c clamps - it immediately welded up normally! I think I've run into this before, where a magnet somehow screws with the welding arc. At any rate, I'm glad I figured it out cause I was getting pretty frustrated with it!

I'm going to trim up the edges and polish off the weld splatter before I'm done with it

 

So I picked up a load of metal - it only came to a little over $100 - and that should allow me to do all the bracing of the shell, finish the motor mounts and a few other mods....

I've been getting the rear hubs all figured out - I bought the hub and disc rotors, pressed the hub into the rear bearing and found that my standard offset wheels rub the trailing arm. I also decided to change out the studs so I don't have to carry metric nuts and English ones both. I can always just use a spacer, or If I'm having Force Racing build me some custom wheels they can change the offset for me.

Clancy uses 7/16" studs instead of the 3/8" that come in the Sprite/Mini hubs, however the rear hubs are for a Miata, and use 10mm studs - which is slightly bigger than 7/16". In fact, the 7/16" studs just dropped into the holes......also the spacing is just very slightly wrong, so as you tighten the lugs you slightly bend your studs. To fix both of these problems, Clancy loaned me a fixture he uses when he drills out the hubs, I put the new, slightly smaller diameter 7/16" studs into the holes and bolted them to the fixture - that pulled them straight and there was just enough play in the holes that the studs came out straight too. Then I welded them to the hub. I just tried them in the wheel and they pull up nice and true....

Next I'll press out the 3/8"studs from the Mini front hubs, drill the holes out and press in the 7/16" studs....since those holes will be the right size I won't have to weld them, the splines will hold just fine. 7/16" studs will torque at 70-80 ft lbs too (compared to the 45 ft lbs of standard Mini studs), which I think will be a good idea considering the extra HP and sticky tires I plan to run





The reason I'm focusing on these rear hubs is once I have the motor mounts finished up then I can measure the length of the axles I'll need and get the shop started on them......no telling how long it will take them to make them but judging on their past performance I'm expecting it to take a couple of months!

 

Built the motor mount for the transmission end today, next I'll build the connections to the gearbox.....then do the same on the other end.

Once that's done I'll need to build a bracket to keep the engine from rocking - I've got a couple of good ideas but haven't finalized any plans yet.

 

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 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 that sold me the subframe included the axles as part of the deal but couldn't make them for me till they had all the correct measurements. But before they can do anything I have to finish the mounts - all of them.





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 them 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 mounts designed, cut and fitted, need to weld it all up now. Then I'll do the other end.....

 

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.

 

So much more to do tho.....

 

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.

 

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.....

 

Well, the guys on Grassroots Motorsports think the 3/8 will be plenty strong enough, so Ima leave it for now and carry on with other parts of the build.

 

A little pause in the action on the hot rod.....holidays, my granddaughter's wedding in Phoenix which I drove to and so on. I did get the parts I needed to fix my welder and now it works well again, so back to work. I also got pretty much all the extra metal I need to make supports, brackets and other bits.

Now if I can just get Mini Tec to answer the damn phone - I still need my rear coil overs, brake calipers and they owe me some axles.

I did finally get the Ford axles taken apart - I was trying to remove the outer CV's off the axle shafts and they would not budge. The funny thing is they moved on the splines OK, and there wasn't any rust or damaged splines on the ends of the axle shafts. The final answer was to cut the races with my angle grinder so I could get all the balls out, then once the only thing left was the inner race - I took that over to the 20 ton press - it didn't budge! So out came the death wheel again......I thought cutting a split in the inner race would release it.....nope! I wound up cutting 4 or 5 places on the race in two before that final bit popped off! What a pita!

Once I had the axles on the bench I found some interesting differences, so I'm going to re-measure for the lengths I need. My plan is to use the Ford Axles rather than start from scratch. But, if they decide that won't work then we'll get some Cromemoly bar stock and get to making them up - at least they'll have the Ford axles to use to model the inner ends off of....if I can't get a response from MiniTec I may take them out to the guy in Burlingame, tho he warned me that it would be a while before he could get to them.

These are quite a bit thicker than the Miata axles MiniTec uses so there should be plenty of meat to cut the new splines on the outer ends.....once I decide exactly how long to make them. It would help if I had my coil overs so I'd know exactly how much suspension travel I have to account for, but I think I can get close enough.

First pic shows the difference in the inner ends, second pic the size difference with a Miata axle (top)

 

Finally heard back from MiniTec this morning after leaving yet another message, they claim my coilovers will be here on Friday. I need those so I can see how much axle length I need to account for suspension travel. Once I have that I can send off my axles with the measurements and get them started on those.

It's been 1 1/2 months since I first contacted them about the shocks and axles, I must have sounded more pissed off in the last phone message I left yesterday!

While they're doing that I will get the hole cut in the back and start fitting up the subframe into the car.....that will be a big moment in this build!