MG Midget Madness (i.e. It was either this or kill it with fire)
 

https://c2.staticflickr.com/8/7569/1...b404ca10_z.jpglowered by Kevin Frank, on Flickr

1975 MG Midget - 1500cc; 4 speed. 1640lbs. with the cast iron engine and trans.

For those of you that don't know what kind of an idiot I am, I will give a brief explanation. I bought the above green hair removal tool to get around with until I could get my 79 SA back up. It seemed to only need a few things and I could either do a swap on it later, or fix it and make a little bit of money by selling it.

No dice. Every time I fixed one thing something was broken/screwed up that had been hidden away by the previous owner(s), or broke in the process of fixing something else. After about a year of fighting with it non-stop, and putting far too much money in it, (2 engines, 2 transmissions, carb, manifold, ignition, switches, wiring fixes, radiator, lights, etc etc. ad nauseum). I have had enough with the weak kneed, poorly designed and built, crappy 55hp engine and glass transmission (and worse wiring). Time for something infinitely better.

I have put quite a bit of work into suspension/interior/exterior so not all the money dumped into it will be wasted.

I will be cleaning up the '87 S4 NA 13B and 5 speed that I have and transplant the whole shebang into it. Hopefully I'll be able to retain the fuel injection, but we'll see as I go along. In addition all the wiring will be stripped out of it and either tossed in the trash, or burned in a black Sabbath bonfire to help it on it's way to hell. I will be using the GSL-SE front cover and pan to utilize the front engine mounts. The trickiest part (other than wiring) is going to be building a header, as there isn't a lot of room.

More pictures to come as I get stuff done.

Dun Dun DUuuun!

Nice. A friend's father has a midget, they are a nice little car. Sticking na in a soft top is a good idea I think you would be popping windscreens otherwise. There is a guy on the adaptronic forum who has a big turbo setup in one of the hard tops :rofl:

That was my thinking. I doubt this chassis could handle large amounts of torque without deforming. An NA rotary should be the perfect swap in one of these. Lots of power, but low end torque should not be excessive. We'll have to see how it comes out.

https://c4.staticflickr.com/8/7740/1...4e5ddffa_z.jpgengine2 by Kevin Frank, on Flickr

before picture, pretty, but a PITA.

If you would like a S4 NA engine, I just so happen to have on sitting on my kitchen table. :suspect: Good luck, Gunny. Your luck with cars is about the worst I've ever seen.

I may take you up on that whenever I manage to get any money. (The green appetite ate it all). A spare engine would be a good thing, especially if the curse is transferrable.

Just let me know. It has sat a really long time so it could probably use a freshening up, but it was fully operational when it was pulled out years and years ago.

Nice! A coworker of mine has been working on a custom chassis/caged Midget built around a 12A for some years now. I keep trying to convince him to ditch the 12A and go with a 13B.

oooh gunny the MG guys are going to black ball ya lol ... you can do this ... am curious of the outcome ... good thing about the tiny tires is they should break loose before anything breaks lol

That is one of the good points to this swap Ray. :reddevil:

The tires are the new ones I bought for the 79, They were OK with this engine, but they did break loose pretty easy on the RX7. I'm hoping to get it down to 1500lbs (800lbs lighter than the 79 RX7) which will only make matters worse, but fun. Now if I can only figure out how to get the waffles on there.

:edit: engine and trans are back out. I may end up using my Weber 45 side draft as it would be simpler, but I really like the reliability and ease of the stock fuel injection. I've heard that the stock FI intake will hit the hood, I'll have to try it and see for myself.

My next door neighbors 13b 6 port. Webber carbs, header. Pretty fun to drive!

I know this swap has been done quite a few times in the past, but I've never seen one. Let alone got to drive one. Do you know what he did for a transmission? It's looking like I'm going to have to move the shifter box forward 8.5 inches if I use my NA 5 speed.

Its a 86 or 87 box. The tunnel has to be modified to work. thus picture doesnt show but its the exact same color as yours.

Fixed.

Then just drop everything lower and further back a la Brian style.

Looks to me like there's room for a third rotor. :suspect:

I think the SA tranny will get the shifter closer to where you need it. Or maybe you can
futz with the tail shaft to shorten it. Either way you will need a custom driveshaft anyway.

I'm going to try, but there is not a lot of room to play with. I hate to move the engine too far back as the weight is already biased toward the rear.


The SA trans will only move the shifter about 2 to 2.5 inches, an RX8 trans would move it 3.5 inches. Either way it is far short of the 8.5 inches that it probably needs to move to keep the shifter in the stock position. I am a little worried on tail shaft length though as the drive shaft is already pretty short. If I get the driveshaft too short I'm likely to have vibration and U joint binding problems.

Doing the trial fitting. I'll try to document what I ended up doing as thoroughly as I can, in case anyone else ever wants to give this swap a go. I haven't been able to find any build threads on this swap that were very complete. Lots of questions on how others did it, but they didn't share.

Things are even tighter than I thought. I needed some room up front as the front of the rotary is more squared off and wider than the 1500.

1. original front cross member:

https://c4.staticflickr.com/8/7679/1...81829ffe_n.jpg1. original crossmember by Kevin Frank, on Flickr


2. sliced, hammered down, and re-welded:

https://c2.staticflickr.com/6/5325/1...d30b2895_n.jpg2. sliced and welded by Kevin Frank, on Flickr


3. Trimmed and completed front cross member:

https://c1.staticflickr.com/9/8778/1...1d6892d8_n.jpg3. completed crossmember by Kevin Frank, on Flickr


Gained 2.25 inches of room up front so I can set the engine down between the frame rails. It looks like I'm going to have to do some clearancing on the rails and the heater box area to the back of the engine as well.

Are the shifter distances you are talking about with the shifter shaft shortened and shifter housing moved forward of standard on the mazda boxes? Everyone does it to rx7 boxes here in aus to fit into the older rx bodies.

Yes, that is what I am contemplating. I know I'm going to have to shorten the shaft and move the box quite a bit, because I would like to keep the shifter in the stock position. We'll see for sure how much I have to move it once I get the engine settled into final position. Hopefully I won't run into problems shortening it as radically as it appears that I will need to.

After more trial fitting, it has become apparent that the engine will not go in there without removing the shelf for the heater box and the ducting underneath it (The back of the engine block hits the ducting). I went ahead and took the battery tray out as well. This provides a lot of room to the rear. You could put a straight six in there with this part out. In fact one person did put a Jaguar DOHC six in one. It should also make taking the engine and transmission in and out a WHOLE lot easier.

original heater/battery tray:

https://c2.staticflickr.com/6/5447/1...22d287a2_n.jpgheater box and battery tray - original by Kevin Frank, on Flickr

heater/battery tray removed:

https://c4.staticflickr.com/8/7740/1...96ef5cae_n.jpgheater box and battery tray - removed by Kevin Frank, on Flickr

Once I have the engine where it needs to be I'll look at rebuilding a spot for the heater. I can do without A/C if I have to, but a heater is important, even if it's only to defog the windshield. The battery will be relocated elsewhere.

Getting that shelf out wasn't easy. I had to drill out a bunch of spot welds, make cuts with the plasma cutter, and do the fine cutting with a cut-off wheel so that I didn't damage something I needed.

Another necessary modification. The permanent transmission crossmember is too high to slide the transmission into the tunnel. Technically all it really needed was to be notched so the transmission would clear. However a non-removable crossmember makes it a royal PITA if you need to drop the transmission. With the permanent crossmember you have to pull the engine and transmission in one unit to get it out of there. I went ahead and removed the center section of the crossmember and will fabricate some plates for the ends and bolt the modified section back in so that I don't compromise structural integrity.

original:

https://c4.staticflickr.com/8/7792/1...9b5eeca7_n.jpgtrans crossmember - original by Kevin Frank, on Flickr


removed:

https://c1.staticflickr.com/9/8758/1...3e83f78a_n.jpgtrans crossmember - removed by Kevin Frank, on Flickr


Now to try fitting it back in there. It doesn't appear that the transmission tunnel is going to require much modification to fit the NA transmission. I would imagine that the turbo transmission would be a different story as the NA trans barely fits.

... and engine/trans in place about where it has to sit. I still need to notch the lower rails a little bit to allow the engine to sit a little lower, not as much as I was afraid that I would though. About 1/2 an inch on the passenger side rail should do it.

https://c1.staticflickr.com/9/8792/1...1fb495b159.jpgengine placement 1 by Kevin Frank, on Flickr

https://c2.staticflickr.com/6/5458/1...9a0a65160a.jpgengine placement 2 by Kevin Frank, on Flickr

https://c2.staticflickr.com/6/5442/1...2cc5b4a981.jpgengine placement 3 by Kevin Frank, on Flickr


The reason I say that it has to sit here is that it lines my exhaust ports up with the small opening for the exhaust to work it's way under the car. The engine is offset to the right (passenger side) by about an inch to line up with the differential input for a straight line shot with the driveshaft.


https://c1.staticflickr.com/9/8693/1...b6213d9594.jpgengine placement 4 by Kevin Frank, on Flickr


Needless to say the coolant filler neck is going to need to be modified and shortened.

I will need to cut and box the upper part of the passenger foot well to allow me to use the stock lower intake manifold. Just not enough room without doing it that way. Shouldn't be a problem as nobody has their feet or legs in that spot anyway. It's just wasted space, and space is at a premium with this swap.

The shifter definitely has to be moved forward about 8.5 inches, or more. (edit: engine back out, measurement made - 9 3/8")

Good news is that the end of the transmission tail shaft is only about 3.5 - 4 inches further back than the original 1500 transmission. That shouldn't cause too many problems, I hope.

Here's my solution to a really short shifter. The first picture I had to steal off the internetz as I forgot to take a "before" picture. The FB box in the rear is very similar to the FC box that I have. The shifter box actually sits behind the tail shaft. This is a no go in my application.

http://ts1.mm.bing.net/th?&id=JN.ATc...9&rs=0&p=0&r=0

So I moved the box forward 9 inches to put it in the stock MG shifter location.

https://c2.staticflickr.com/6/5327/1...980189a420.jpgshort shifter 2 by Kevin Frank, on Flickr

https://c1.staticflickr.com/9/8756/1...9aacb7918f.jpgshort shifter 1 by Kevin Frank, on Flickr

I've seen prettier renditions of this, but this is how I did it.

The mount was cut off right next to the box and I used the side cover plate to attach a mount using the original rear bolts, one side bolt, and the locator pins. The shaft for the shifter was cut 9 inches and the roll pin hole re-drilled. (I had a machine shop do this for me as I always get the hole off center when I try to drill a round rod). The shaft is not hardened toward the rear so drilling it wasn't a problem. I also had to do a little "massaging" with a grinder on the tail shaft housing. This was necessary to get the box to sit all the way forward against the opening that the shifter shaft exits the case.

It works, but it seems a little stiff right now. Could be that the shaft is binding a little bit which should work it ways out as it gets used or it may be that the RTV I used between the box and the case is pushed up against the shaft. :dunno:

It does go in and out of all the gears just fine, so I'll give it a try as is.

Right now I'm working on notching the lower frame rails to give me enough room to drop the engine a little lower in the frame.

thats a cool trick , looks great

Thanks mattalac. Plenty of people have shortened the shifter before, but they usually didn't have to move it quite that far. The better way would have been to weld the box to a mount. I don't have a machine that will weld aluminum, so I went this way.

After about five days of work I finally have the frame modifications finished to make the engine fit in there the way I want it to. It took a while as the mods were more extensive than I thought they would be at first.

You can see the original frame in the original crossmember picture above. (as usual I forgot to take a before picture)

modified:

https://c4.staticflickr.com/8/7723/1...067db06c_z.jpgFrame mods 1 by Kevin Frank, on Flickr

https://c4.staticflickr.com/8/7689/1...00437dda_z.jpgframe mods 2 by Kevin Frank, on Flickr


The rotary is a lot wider at the bottom and made it necessary to widen the rails to set it down low. All the other threads I've seen on this set the engine above the frame rails, with attendant problems of the oil pan rails occasionally hitting. Not to mention what it does to the center of gravity.

I welded in two 1/2 thick plates to the outside of each rail between the body tub and the suspension points. Excessive, but it covered the existing flange on the bottom of the rail perfectly. I then trimmed one inch from the inside of each rail and welded 1/8th inch plate to close off the inside. I had to notch the driver's side rail another inch or so for the oil cooler line and the oil bypass sticking out the side of the bottom middle iron. This ended up being the entire width of the rail except for the outer layer. The front crossmember had to be further trimmed to give me enough room to push the engine a little further forward. After taking part of it off I closed it in with more 1/8th inch plate. I then welded in 8 studs and crush tubes along the sides and front for a skid plate/ frame stiffener. It will bolt underneath to tie the entire front suspension together. It will be considerably stronger and stiffer than the original.

Most people don't go this far for the swap, but I'm kind of anal about chassis stiffness and a low center of gravity.

The fruits of my weekend.

After much trial fitting and head scratching, by Jove! I think I've got it. Engine mounts that is. There wasn't enough room to use the FB or FC stock pads so I improvised with polyurethane captured mounts originally intended for use in rear suspension lower swing arms.

https://c4.staticflickr.com/8/7727/1...ea15818145.jpgengine mounts 3 by Kevin Frank, on Flickr


https://c4.staticflickr.com/8/7789/1...234573a646.jpgengine mounts 2 by Kevin Frank, on Flickr


I will extend the front mounting plate over to each and bolt it to the top of each polyurethane mount. There's not a lot of give in this setup so engine placement is going to have to be pretty exact as far as engine angle vs. pinion angle before I weld it up. I used the bolt on approach because if I had simply welded the front plate to the mounts interference from the tabs would have made it nearly impossible to pull the engine without removing the front plate from the engine.

looking good

Thanks. Getting there. It's taking a little more than I thought at first to get it where I want it.


Engine support bar done and the engine is mounted. Lots of fiddling to get bracing in there without interference. As you can see, not a lot of room to work with. This was as low and right as I dared to go. I plan to modify the oil pan/pickup to make the sump shallower and longer. I have full access to the bottom of the pan, but it does hang pretty low with the engine this far down.

https://c4.staticflickr.com/8/7789/1...49e5d7037b.jpgengine crossbar 2 by Kevin Frank, on Flickr


https://c4.staticflickr.com/8/7792/1...23070c62d2.jpgengine crossbar 1 by Kevin Frank, on Flickr

When is the first fire up? Looks like you are moving right along.

Not sure yet. Depends on whether I go fuel injected or just use the 45DCOE I have. The Weber would be a lot faster, wiring wise, but then I have to use my points style 12A distributor and figure out the wiring for that. I like the way the fuel injection works though and keeping everything stock FC eliminates a lot of tuning hassles down the road. :dunno:

Working on transmission mount now. I stole the poly T-5 trans mount I had for a 5.0 Mustang and am adapting that. It is actually fitting fairly close and is only requiring minor modifications to fit. The T-5 mount is quite tall for most uses, but should work fine in this application, I think.

Working on transmission mount.

I cut out the original fixed transmission crossmember as it makes getting the engine in and out a royal pain. The problem with cutting it out is that there is nothing to bolt a replacement to. The crossmember is only boxed light sheet metal and is insufficient for bolting a heavier gauge center section to. My solution was to use 2 3/8ths outside square tubing, which slid into the stubs nice and snug. Finding that size tubing is a bit of a bother, but it works perfectly. I then used 1/2" bolts to fasten it within the frame rails. Capped off the ends with some 3/8ths plate and welded nuts inside for both the facing plate and the frame fasteners.


https://c1.staticflickr.com/1/298/18...392a0be4e4.jpgtrans cross member attachment point 2 by Kevin Frank, on Flickr


https://c4.staticflickr.com/8/7744/1...4664931e00.jpgtrans cross member attachment point 1 by Kevin Frank, on Flickr


There will be a 2" wide (1/4" plate) strip bolted underneath, as part of the center section, with the rest of the center section bolted both below and to the sides. I planned it like this so that I wouldn't be hanging the mount from something that the bolts were in shear.

more pics when I get that done.

One transmission crossmember; done.

I have to wait for the paint to dry then I can re-install it and post a picture of it installed, with the transmission sitting on it, tomorrow.


https://c1.staticflickr.com/1/391/18...6845075d3d.jpgnew transmission crossmember by Kevin Frank, on Flickr

as always, i'm quite impressed with your work. i think if you already have the Weber setup in hand, then you should use it. you could always take the EFI road later on. besides, it would give you a jump on ironing out some wrinkles before the EFI wiring headaches.

I have the carburetor, but not the manifold. The carburetor would also need extensive re-jetting as it currently has 36mm chokes which would have to be changed out for 40s, along with the emulsion tubes, idle and main jets, etc.

I keep waffling back and forth on it. I will have to see when I try to re-fit my hood (bonnet for Brian) with the engine in there. If it doesn't fit with the EFI upper, which is what I've been told, then I'll definitely be using the Weber.

This car has made me want to join you in that bottle of Glenfiddich on a great many occasions.

ahhh ... understood. it's not complete. although, it also sounds like the writing is on the wall, so to speak.

understood again ... completely. :D

As promised. Pictures of the finished transmission crossmember installed.


https://c1.staticflickr.com/9/8856/1...1619261244.jpgtrans crossmember - new - installed by Kevin Frank, on Flickr


I couldn't get the bottom rear side bolts in, there just isn't enough room to get a wrench in the limited space to tighten them. It should be fine with three 7/16ths bolts per side though. Quite often things don't quite work out the way I intended. :lol:


While under the car I took a shot of the frame modification I did for the starter. The starter had me worried, but it fit fine. The only problem was having enough room to get it out without having to pull the engine to do it. I considered that to be what you would call a "bad" thing. So I laid the frame rail back a bit and plan to bend and weld in a piece of 1/8th inch plate to reinforce that spot while leaving me enough room to service the starter when it needs it.


https://c1.staticflickr.com/1/361/17...cc82448305.jpgstarter frame relief by Kevin Frank, on Flickr

It fits!!!! :snoopy happy dance:


https://c1.staticflickr.com/1/292/18...b6534b5d_c.jpg13B final position by Kevin Frank, on Flickr


The hood closes with the EFI manifold on the engine. :) :) :)

I have about 1/2" of clearance at the closest point from the top front edge of the manifold to the underside of the hood. Even the filler neck for the coolant fits with plenty of clearance. This is rather astonishing to me. I figured and measured and planned it out to get the engine low enough for it to go in there. I'm actually about two inches lower than I have seen anyone else set the engine in one of these. That two inches was a LOT of work to get though. When you're juggling as many variables as there are in locating an engine in a space this small I've come to expect things not to quite work out right. I's a happy camper right now.

I did have to trim a little more than I expected from the passenger foot well though. I don't think that it will be a problem with where it's at, but if anyone complains I'll just punch it and they'll be so busy hanging on they will forget all about it.

Schweet!