Thanks. Oh yes it is! Getting that S4 EFI manifold to fit under the hood was one of my biggest hurdles when planning out this swap.

It is a plus having an engine that fits under the bonnet..:rofl:

Nice work Gunny! I'd give you grief and tell you to slap a turbo on it, but after seeing how little room you have to work with in that last picture, I'll just keep my yap shut! :rofl:

It is just a skosh tight in there. :rofl:

So this is what I spent an entire day doing. Just one little piece of tube, that's all. Right!


https://c1.staticflickr.com/1/490/18...c55b3d8138.jpg13B header 1 by https://c1.staticflickr.com/1/302/18...c428fb8af5.jpg13B header 2 by Kevin Frank, on Flickr


well besides the tube, I did get the O2 sensor bung welded in, so that's two things I guess. :)

I am modifying the Racing Beat 6 port header, that I already had, to fit in the midget. It will have to be a two piece design if I am to have any hope of ever getting it in and out of the car. This is the upper portion mating to a road race outlet flange. It will be mated to a lower section using the same type of flange and making an immediate 90 straight back. Needless to say there was lots of fiddling to get it just right so that everything would go where it needs to. Now that I have a better idea of what I will need, I ordered some more flanges, bends, and straight tube from Racing Beat to finish part of the exhaust system.

S4 specific Six port actuator tube installed. Has to be at just the right angle and spacing to make it possible to still slide the header out of there.

https://c1.staticflickr.com/1/403/18...ec50fe7f09.jpg13B header six port actuator tube by [url=https://www

For those that try something like this be a little more careful welding in the O2 bung than I was. Went to take out the plug that I had protecting the threads and found that I had welded the threads together at the bottom. :banghead:

I had to grind it back out and weld in a new bung.

Had a question on it so I'll post this a little early.

I'm going stir crazy waiting for more pipe from RB, so I started figuring out the other big bug-a-boo with this swap. Cooling.

Since the rotary requires far more cooling than the original piston engine, and frontal area is so limited, I had to plan out some rather strange stuff. The FC radiator is a single pass unit with 374 square inches of frontal area. The oil cooler carries about 30% of the engine cooling and is about 91.5 square inches of frontal area. The original MG radiator has only 140 square inches of frontal area and no oil cooler standard. Obviously we have a problem Houston. The tiny opening was going to need some rethinking to get a lot bigger radiator in there, not to mention what to do about an oil cooler.

Here's a picture of the original opening after I had made some cuts to open it up a little. The Diet Coke box was supposed to only be background so you could see the opening better. Didn't work so well, but you get what you pay for.


https://c4.staticflickr.com/4/3669/1...9c5a2d7306.jpgradiator opening 1 by Kevin Frank, on Flickr


I'm going to open it up to the full width of the car. Removing the front stubs of the upper frame rails so I can fit the side tanks all the way up against the sides and maximize my radiator size with a 14" x 28" double pass radiator. I'm still down a little on frontal area from the FC radiator at only about 336 square inches, but I hope the extra efficiency of the double pass unit will make up the difference. Unfortunately it is going to have to be custom made so it's going to be expensive.

The oil cooler I plan to use is an 11"x11" square stacked plate cooler that I will set underneath the radiator and between the frame rails. It is actually about 30 square inches larger in surface are than the original. However because I plan to mount it flat, (not much choice as there is just no room anywhere else), it will have less than great air flow. I plan to run a shallow scoop under the car to gather air for the oil cooler and run the fan shroud over the cooler along with the fan so that it draws air through both.

A picture of the radiator opening, partially opened.


https://c4.staticflickr.com/4/3769/1...64e93bd19d.jpgradiator opening 2 by Kevin Frank, on Flickr

I have to finish opening it up on the top pieces and cut down the frame rails.

Liking the built and the opinion pictorial from your Flickr account :smilielol5:

There is also the option of upping the coolant flow rate also Gunny and or pusher and puller fans.

Thanks Zach. I'm trying to make the thread as useful and entertaining as I can for anyone else stupid enough to do one of these conversions. There is nothing unique in what I'm doing, it has all been done before (except maybe the EFI if that works out). The problem I had is that the build threads I read through left a lot to be desired. I especially want to show and discuss all the pitfalls and problems involved, including my own screw ups. I'm not too proud to admit that sometimes I'm not half as smart as I think I am. Showing (or at least admitting to) the failures is almost more important than the successes for learning. I see far too many people with their egos on the line in these things and will only show you what went right, or disappear all together when shit doesn't work. The bad part is that it leaves somebody reading it later with the impression that the project/mod was a success and they try it themselves.

edit: I used the opinion picture on EJ the other day. I have to keep an eye out and collect these little tid bits so I can defend myself 'round this place. :lol:

I'll be using a puller electric fan, either a single 14" or a double 12". I'm not quite sure yet which way I'll go. A pusher fan tends to block incoming air so not such a good choice for steady state driving, but if I get desperate it may come to that. Upping the coolant flow may or may not work, too fast and you're not transferring enough heat as the coolant cycles, too slow and you are losing the opportunity to shed more heat. Again if it's a problem I may have to play around with that. I think I'm going to be alright though as I should be relatively close to the stock FC specs. :dunno: I'll have to see once it's up and running.

Yeah you seem to be close enough to spec so I would think a half puller on each for emergency use will be fine. That way you get the best of both free air and forced air when needed.

I see a lot of non clutch fan converted to E-Fan race cars and they all run the fans to the oil cooler. If temp gets around 180 while idling kick on the fan and the temp just drops.

Check out AFCO Racing?
You should be able to find one close, and it shouldn't cost more than $300...?


-Ted

+1 on this. It helps to see the good, bad, and the ugly on projects like this.
I always thought this would be a neat swap but after seeing the amount of
fabbing needed I certainly wouldn't try it. Thanks Gunny for sharing.

I checked them and a lot of others. 14" H cores are non standard. I can get something at 15.5" H, but there is no way I can make it fit unfortunately.


Glad it helps. I have done more fabricating than what most would probably consider really necessary, but I'm picky on how I want it to fit. There is a fair amount of fabrication involved with this swap no matter how you go about it though.

This is an out-of-the-box thought, but have you considered relocating the radiator and/or oil cooler out back? That would present a bunch of other problems, like proper airflow and plumbing/packaging, but it might give you more space to work with and solve the capacity/radiator size issue.

You don't need no steen-king trunk space, right? :rofl:

I have almost no steen-king trunk space to play with Pete and even less room to duct air to it. :lol: This car is tiny. I had forgotten just how small they were until I bought the damn thing. It is about 10 1/2 feet long without the bumpers, 48 1/4" tall, and only 4'5" wide. I'm already going to have to cut into my trunk space (or should I say "the rear glove box"?) later in order to expand my fuel tank a bit when I modify it for an in tank pump and cup for the fuel injection. The original fuel tank is only a 7 gallon tank which may be a bit less than optimal with a rotary. ;)

It looks like they have a lot of 27.5" / 28" by 19" stuff...
Can't you just cut the core down and redo the endtanks for your application?
Can't be more than $100 in labor and welding locally?


-Ted

The one local place, that I would trust with something like that, won't do that kind of work on aluminum radiators. They must have gotten burned on it at one time or another for them to be that gun shy of it. I don't have the means to weld aluminum myself. I really need to do something about that lack one of these days.

Maybe ship it off to Brian T.?

That might be an idea, but Brianna's busy as hell these days. He hasn't got time to work on his own cars let alone anyone else's.

Send it Cheebs?

That's a good idea, Cheebs has plenty of time, but not sure if he does AL?

I'll talk to him when I'm up there. but I think that modifying a double pass radiator and pressure testing is beyond the tools he has available. It would have some of the prettiest welds ever seen on a radiator though. ;)

Yeah I don't have any GTAW available at all at the moment.

front radiator opening fully trimmed with the frame rails trimmed back to allow access for an over size radiator.


https://c2.staticflickr.com/6/5581/1...49341096ec.jpgradiator opening by Kevin Frank, on Flickr


... and the back side.


https://c4.staticflickr.com/4/3714/1...c8166d0553.jpgradiator opening (back) by Kevin Frank, on Flickr


This is the maximum opening that I could manage.

upper 2 piece exhaust manifold/header finished and painted.

https://c4.staticflickr.com/4/3679/1...c1e1f16129.jpgupper exhaust manifold (finished) by Kevin Frank, on Flickr


installed:


https://c1.staticflickr.com/1/395/18...ee0982a78b.jpgupper exhaust manifold (installed) by Kevin Frank, on Flickr

That turned out pretty darn good didn't it??

I was pretty pleased with it. Not anywhere near as pretty as Racing Beat's header, but they don't make one for a Midget swap. :lol:

Finished the mid pipe section and got paint on it. I will probably need to make up some heat shields for the pipes. They have to run pretty close to the floor pan as there is very little ground clearance on these and nowhere to tuck the pipe up and out of the way. I still have about 1/2" of clearance, but didn't dare tuck it up any higher due to the rotary's high exhaust temperatures.


https://c1.staticflickr.com/1/438/18...c8f4b0d4_z.jpgmid pipe 1 by Kevin Frank, on Flickr


The end of this will connect to an X pipe section that passes underneath the transmission. It will bolt to the exhaust on either side of the tunnel opening. This will give me a section that I can drop out to remove the transmission, without having to take out the entire exhaust system each time. The downside to this approach is that there are more gasketed joints (and possible leak points) in the system. Once out of the X pipe section, I plan to 90 the dual pipes toward the rear of the car (putting in another flange just before it turns up to go over the axle) and all the way over the axle before I run it into a 3" collector at the back of the axle tunnel. At that point it will go to a 3" Racing Beat pre-silencer, make a 90 into a 3" RB muffler, then make another 90 out the back on the passenger side. The reason for this is more so space considerations than for the long primary. Space is so tight over the axle that the 2" pipe is going to be a tight squeeze, anything bigger would be sure to hit on suspension compression. That's the plan anyway.


https://c1.staticflickr.com/1/269/18...9031a205_z.jpgmid pipe 2 by Kevin Frank, on Flickr


and a shot of where it connects to the upper section of the header/manifold.


https://c4.staticflickr.com/4/3685/1...e5b0aed5_z.jpgmid pipe 3 by Kevin Frank, on Flickr


Probably not going to get a lot done for a couple more weeks as I have to make a trip up to Montana.

What paint are you using on them? I assume its all MIG'd...

VHT 1500 - 2000 degree header paint and yes it's all Mig'ed. I'm not baller enough for TIG. ;) I'm not the world's greatest welder, but my welds don't break and they don't leak. Usually anyhow. :lol:

The VHT stuff is decent - used on the RX3 headers but in black. DId you "bake" the aint at all?

The first time I fired my headers up they smoked for a while burning in the paint..after a while it was all good and still black so I'll be curious to see how the silver looks.

Welds look fine too!

No, I didn't bother to bake it. Once it gets fired up it'll get "baked" on. :lol: I used the same paint on a previous header I had sand blasted, then painted. Worked well. Not as tough as Ceramic coatings in that it will chip more easily if you drop stuff on it, but a lot cheaper and easier to touch up when you have to. Mainly I just want to keep them from rusting.

If anyone is looking for a show quality build, then my builds aren't it. They will have to look elsewhere for that kind of eye candy. ;) I just want the damn thing to work, and work well. The information I present is for others to see what my solutions were to the build so they can plan accordingly if they choose to try something similar.

A picture of the other header, it didn't discolor and held up under use, admittedly not a lot of miles, but it didn't burn off with the four cylinder. How well that holds true for a rotary we'll have to see.

Attachment 15912

Thats why I use it too, protect the rust and pipes from weld. Good for cheaper builds that get driven (I don't build many show cars, lol).

I'm relaying all your progress to a co-worker. In 15 years he hasn't made as much progress as you have in the last few months. I like what you're doing with the exhaust. The fact that you're thinking ahead and planning for disassembly is something few people (even shops) do.

It's a Little British Car, not planning for future breakage would not work out so well. :lol:


... and for what I accomplished today. I made a somewhat complicated bracket and mounted my AFM up at the front of the engine. I wanted to use the stock 13B intake piping and the radiator would be in the way to mount it in the same place as the RX7. I plan to run the intake across the front of the engine (up high and behind the radiator shroud) and plumb in a cold air intake and filter box on the driver's side. I'm trying to figure out a way to tuck the filter box high in the wheel well, directly behind the headlight, as this is the only reasonably clear unused space up front. Still puzzling over that one.


https://c1.staticflickr.com/1/312/18...207726d57f.jpgAFM bracket by Kevin Frank, on Flickr


https://c1.staticflickr.com/1/519/18...826ef436e4.jpgAFM placement 1 by Kevin Frank, on Flickr


https://c1.staticflickr.com/1/557/19...5392c9c6c6.jpgAFM placement 2 by Kevin Frank, on Flickr


https://c4.staticflickr.com/4/3901/1...b8e19187af.jpgAFM placement 3 by Kevin Frank, on Flickr

Does that pipe clear with the hood closed? Looks close...

It is close (just like everything else in this 5 lb. sack ;) ), but yes, it should. The hood bulges upward toward the middle with no inner structure, which is the only reason that my manifold clears. I'll see for absolute sure next time I trial fit the hood. It wouldn't be the first time I had to go back and re-think something.

edit: damn it Ransom, you got me worried and I had to go out and reinstall the hood to check it. :lol: There was a clearance issue. Not with the hood per se, but with the mounting tab for the hood prop. Chopped off the tab and it closes just fine.

Wheww! Good eye. :biggthumpup:

I do have another clearance issue with the thermostat housing pipe. It touches on the inner curve of the bend. I was planning to cut and swivel that to a more forward angle anyway. The outward angle is a bit extreme for this car and now that I know it touches the intake piping I'll definitely need to modify it to face further toward the front of the car.