Most liked posts in thread: Mini Ecoboost Project

Work plods along, today I built the corner lower brackets for the subframe. I bought some flanged nuts to weld into the sheet metal so I can unbolt them when I want to remove the subframe. Next I'll weld the rear valance panel into place, then I can bolt these in and try the rest of the cage for fit.





I also acquired a sport pak arch from Dan to try, it fits perfectly but the inner edge return will rub on the tires unless I remove it, which might make the arch flimsy. I need to bolt a tire back on, remove the temp brace and reinstall the shock so I can see how far up into the arch the tire goes, and how far out it sticks. Ima give the arches some more thought before I do anything. Plenty of other work yet to do anyway......

 

It's actually a 94 SPi shell, so it has the later Nikei instruments, so they should take info from the ECU - at least the tach would - but even then the speedo, temp and fuel gauges were all analog - the speedo driven by a cable off the transmichigan rather than via a VSS and the temp gauge from a sender in the head. So, if I can get the original instruments, at least the tach, water temp and speedo should get their signals from the ECU. Fuel gauge will be some sort of aftermarket tank, pump and sender.

Shifter will be "interesting" too.....

At least it has a hydraulic clutch, so that will be fairly straightforward....

Gearing will be a challenge as they came with 18" wheels and it will have 13's now......based on standard tire circumference the RPM difference will be about 1.6, that's a lot. First and maybe 2nd gears might be throwaway gears. I might be able to find a taller diff out of a diesel gearbox, but those were never sold here so I'll be looking in either England or Germany, or have to buy a custom one somewhere/somehow. I've changed them in Honda gearboxes on Vtec conversions in classic Minis, it makes a huge difference in drivability to have the right diff ratio.

 

I sent another email to my engine supplier as he's gone radio and email silent over the last 10 days or more.

In the threads of guys who have used them they also said communication was not easy or regular with these guys, but as they seem to be the only one doing the Ecoboost conversions, so they put up with it and in the end got the exact package they wanted Worth the wait if the end results work out I guess.

Dan picked up my Fortech flares from my sister's place in Denver - his only comment "they're huge!" I got them from a guy in the Rocky Mtn region Mini club, I guess he bought them for a project he was doing and went another way. As they're unobtanium now I was happy to score them for my project. Mania sold them for $900 a set last time they had them, which looks to be a while ago. 7Ent had them for less but neither has had stock for over a year.

 

I don't even have the car at my shop yet.....once it's here I anticipate getting the engine/trans mounted first, then see about the body - I'll be figuring out how to get air into the engine, probably have some vents cut in the front edges of the rear flares. Working out if I can have a rear diffuser too....whether to use a rear mounted wing, close off the bottom of the front under the subframe giving a flat floor - all that sort of stuff.

 

I haven't seen the video yet, but the engine I bought also uses the belt that runs in the oil......

Edit: After watching the video it's clear that the tensioner failed, which took out the belt, then the engine was running without oil pressure.....which is probably what killed the turbo bearings too. But it's also clear that you'll need to replace those timing belts as a maintenance item.

I was planning to change mine anyway,

One thing fun, I found out my engine only has 39K on it.

 

I've been working on my fuel tank, I cut the end off as I knew it had to be shortened to fit in the front end (by my calculations I'll have right at 10 gallons) and so I could fit the in-tank fuel pump and pickup. I'll also need to relocate the fuel sender and find a bulkhead fitting for the wires for the pump. I'm also considering making some baffles - one to surround the pickup and maybe one in the middle to keep the fuel from sloshing around as I drive. Dunno about that yet....




I'm also figuring out how to mount the tank solidly, whether to use straps ala Binky or use some rubber padded angle iron.

 

Absolutely. That's why I want to get the rust cut out and repaired before I cut the big hole in the back. I'll brace up the rear first....the front subframe will keep the front end lined up. Lots to do before I get there, and now that the weather is cooling off I'll be able to spend more time in the shop.

 

I know it's been a while but this project has not died, I just had to put it aside to complete some other work. I build transmissions for Sprites, especially for racers (straight cut gears) and I owed one to a guy - then a friend of his came in with one for his Bugeye - which became 2 when the one already in the car blew up also (turned out it was run thru two racing events with no oil in it. I've never seen a gearbox that dry! Some of the gears were blue)

So coupled with the holidays, some final electrical work needed on the Inno before it leaves in Mid Feb, a wedding for my grandson and who knows what else I'm almost ready to jump back in on my project once the Inno leaves. In mid-Feb I'll be taking it down to Tulsa to the new owner, and picking up my Racing Green Mini from his shop after he painted it - which turned out really well!

More as it happens!

A few pics of the Racing Green in progress - he still needs to cut and polish most of it. The racing stripes are painted on. Can't wait to get it back....since this is a part time gig for him it's been there since last August. Should get it back just in time for some spring driving and events.

 

Red letter day, major parts being delivered this afternoon......rear subframe, roll cage, axles and rear coilovers. Next up, trying to figure out how to mount the motor in the subframe......it's built for Hondas, and I'm putting a Ford in it.......

 

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.

 

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 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 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.