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MG Midget and Sprite Technical - Round wheelarch conversion

I need to replace the lower rear wings on my car and I would like to change it to round wheel arches. Does any one now the best way to do this and where I can get the parts. I have someone who will make lower wing repair panels but they seem quite expensive.

Thanks for any help Carl
C Bintcliffe

If you've got the space buying a parts car with an intact rear section wouldn't be a bad idea.
Rich Amos (1330cc Blaze Red '72)

Carl, that thought has crossed my mind too once a while so i could get bigger wheels/tyres on the midget.

Isnt it "just" cutting out the old wings and part of the inner wings, get rwa inner and outer wings and weld it together and then fabricate the other halfs of the tailpieces that go under the realights.
Or just put in a 1275 rearpanel while your holding a weldermachine anyway?

Mine is a 1500 too, i only pushed out my arches to get wheel clearance for my 175-65-14 wheels.
175-6-14 would probably not have rubbed against the inner arch.
I did replace the rear panel tho for a 1275.


Arie de Best

Carl, MGOC shows the replacement panels for both the outter side of the inner arch and the outside wing panel for the round arch midget. With those panels you should be able to do a conversion fairly easily, no worse than normal rust repair. They're the only source that I know of for the RWA panels.
Bill Young

MGOC just resell, don't actually make anything, so I would expect you can buy them elsewhere and cheaper too.
David Smith

I checked the Moss Europe, Moss US, and Victoria British sites, none lists the panels for the RWA. These panels are comming from the Heritage press, they started doing a RWA Midget shell a couple of years ago, but I haven't seen any other supplier other than MGOC sell them, perhaps MGOC has a contract with Heritage.
Bill Young

I'm been think about this too, need replacing so what the heck, someone a while ago was banging on about using Ford Fiesta repair panels as they had the same radius and profile, all went quiet though, guess it did'nt pan out. Might be worth following up though
Markdj

Bill I *think* RWA wings are CZJ408 & 409 - listed by Moss Europe but misdescribed as they cannot be for both RWA and r/bumper !
David Smith

I used fiesta rear arches on mine - about £12 ea. IIRC from a local factors.


John Collinson

...and the before shot.


John Collinson

I have been considering the same conversion for when I get round to respraying the car but I thought the inner wheel arches where also an issue?? My car is a 66 if it makes any difference?
J Lodge

Hi Carl, I have an old RWA 1972 midget down the garden. The floors and sills are rotten, but rear wings are not too bad. You are welcome to come and have a look to see if this is any use to you. I am just outside Milton Keynes and can be contacted on 07875 177743. Cheers, Dave ( ignore the Berkshire bit!)
DM Gibson

J, I was going to fit the outter, then cut and weld to fit the inner, what the eye can't see, bit of a bodge i suppose ;-)
MarkDJ

Have to excuse the sloppy english, either brain, fingers or keyboard to blame, probably the first...
markdj

Winners circle here in the USA sells a wide range of RWA in differant sizes...they are fiberglass but vary reasonably priced...Im 90% sure peter MAY sells a simialer Item as welll....and is nicly priced.

prop
Prop

Hi Dave

Thanks for that, I shall ring you over the weekend and see what we can arrange. You are not too far from me so we may be able to do something.

Cheers Carl
C Bintcliffe

If you don't mind f/glass my rear wings are from Peter May. I didn't change the inner part just reshaped it and bonded/sealed it to the new wing.
Lee Reed

Take a moulding from a Lenham? Even more clearance.


rob multi-sheds thomas

Carl, are you still posting here? Did you complete your rwa conversion?

Does anyone know of a cheaper source than the B hive for round arches?
BMH 8020/1 Outer round wheel arch £109.00

I've got a ragged nearside rear sq arch in need of a bit of attention, and this might be a good time to get the rwas I prefer.

Alternately,

Arie,
May I ask what technique you used to push your sq arches out?


Cheers





Lawrence Slater

From memory Carl came and cut off the complete inner and outer wings from my scrap shell. I have another shell available if anyone wants it! Dave
DM Gibson

Arie, "175-6-14 would probably not have rubbed against the inner arch" That would be a quite an expensive tyre and with just over 10 cm high a bit low ;)
Alex G Matla

Quote

** Arie, "175-6-14 would probably not have rubbed against the inner arch" That would be a quite an expensive tyre and with just over 10 cm high a bit low ;) **

Alex, I think you have fallen foul of the mathematical equivalent of Skitts Law! http://sycophant.wordpress.com/2007/02/28/skitts-law/
Geoff E

Ive got a good used rwa both inner and outer

Can i just leave most of the inner arch and cut out just the top portion and replace it with the top portion of the inner rwa, or do i need to replace the entire inner panal

Also... How much of the outer panal do i actually use, can i just replace the upper section where the round portion is going to be installed or does the wheel well section need to be replaced

When i eventually do this I want to make it as simple as possiable
Prop

Ah, yes, it would be even lower. Just a strip of rubber.
Alex G Matla

Prop said: When i eventually do this I want to make it as simple as possiable

> a fresh approach then, Prop ;-)
David Smith

Hahaha...

Well i guess theres always duct tape, bubble gum, and pop riviets.

Im hoping the conversion is simpler then it looks...i could see this becoming a structral fubar mess in under 5 minutes with the right cutting tools.

As the top of the arch weather it is round or square is where all the rear of the cars support rest.
Prop

As I posted in another thread recently, if you're not fussed with it looking exactly like an original RWA Midget then just head to a wreckers with a tape measure. I'm very happy with how mine came up, and it resulted in more tyre clearance than a standard car at significantly less cost.


AndrewF

Andrew, they look really good.

It's the backs I'm most interestd in, and I'm not too bothered about it being original, just look good, and be relatively easy to do.

I'd be happy to just fit the outer arches, original or otherwise if that's at all possible, but don't want to tear mine apart to find out how or what is possible. I'd rather know in advance.

How much more strength does an SWA give over an RWA?

Did you add any metal to privide more strength? Did you by any chance record pictorial details of how you converted your own?

Hi DM Gibson,
Are you willing to split your shell, and have the arches cut out, or is it an all or nothing purchase? I can imagine you would rather sell it as a whole wouldn't you?
Lawrence Slater

okay, okay, I should have written down 175-60-14.
Bunch of "know-it-all"s!! :)

Lawrence, we took 2 piece of would and a hydraulic jack between them, put it in the arch and then slowly jack it outwards.
The would is to make sure pressure is spread and leaves the paint in tact in the wheel arches.
Left side arch kept pulling back tho...
Arie de Best

Thanks Arie.

I'll try that tomorrow with a scissor jack. I suppose then I would have to go more than needed, to overcome the tendancy to spring back. Makes sense.

Actually it's mostly my nearside arch too that needs "adjusting". (Left hand looking from behind car). The other is ok. But the nearside is definitely out of alignment and sits too close to the wheel.

And it's a big ragged anyway, so I'm not worried about the paint. If this works I could decide to keep it square, but I do like the looks of rwa.

Also this is preparation for banding my original steel wheels.
Lawrence Slater

Lawrence
All you need is a short length of 2" pipe. Put it against the tyre and roll the car along the floor. The pipe rolls between the arch and the tyre forcing the arch outwards. This method is much gentler than using jacks.
M H Allen

I think your supposed to heat up the paint with a heat gun to soften the paint and make it more plyable.... Well thats what ive heard anyway... No personal experuance here...

Take some photos id love to see how it turns out

Prop
Prop

2 inch pipe eh? That's an idea I'd never have thought of. Sounds good.

Pictures? :) :) It looks bad now, it won't look any better afterwards lol.
Lawrence Slater

I've used the 2" pipe method too, though on a car (Mazda) that had round shaped wheel arches. Mike, have you done this on a square arched Midget? I'd be curious as to how well it would work/look?

Prop, I have also heard heating the paint is a good idea. When I used the pipe method I did crack the paint on the car I did it on, but I wasn't careful about it as I was painting the car anyway.
AndrewF

Andrew it was someone's square arch Midget at the track and the paint didn't crack. That's not to say it wont on another car, but I would think less likely than using a jack. It really is a gentle process that just eases the guard out slightly. Sometimes necessary to do it a couple of times to work the metal. Increasing tyre pressure will assist also.
I've seen too many guards bruised from the head of a jack or the edge of the timber that was used to prevent bruising - pic shows one example.
NOt heard of heating the paint first. Cracking might depend on how much bog is under the paint.


M H Allen

I did mine some time ago with Fiesta arch repair panels. It might have been me "banging on" about it. Sorry.
I fabricated the inners from sheet steel.

Bernie


b higginson

Bernie, that looks really nice. If I could achieve that, I'd be pretty happy.

Are they metal arches or fibre glass?

M allen. I dont mind a bit of denting or the opposite, I have to tidy the arch anyway, so a bit of tapping with a hammer afterwards is ok. As regards paint, yes I have pudding behind mine anyway, so I am expecting cracks. At least nearside as this is the raggged side.
Lawrence Slater

"we took 2 piece of would and"

Would?????

I meant to write wood!!!!!

Why didnt Dutch became the international language?
Could have made life so much easier for us Dutchies. :)
Arie de Best

The paint on the Mazda I mentioned was factory paint, no bog underneath, but the paint was badly crazed and cracking off elsewhere so it was pretty tired.

Lawrence, I missed your questions before. Sorry, no pictures of it in progress (hindsight is a wonderful thing!). We modified and added to the original inner guards to match them with the modified outers.
AndrewF

Lawrence. The arches are steel. You get the arch shape and about 4 inches of extra metal on the panel. You can then trim the extra to get the correct shape. I've not looked recently, but there were some on ebay a few months ago for £12 a piece. If you give the job a good coat of "looking at" first and use the old addage of measure twice cut once, you should be OK. I tack welded first with just a couple of welds, checked the position then added more tacks and finally seam welded a bit at a time in different places to avoid distotion.

Bernie.
b higginson

Ok thanks Andrew. I going down to my garage to attack my arches with either wood or a pipe.

Actually 2 inch pipe sounds a bit thick at first.

I have an old Triumph Bonneville fork stanchion that is less than 2 inch. I'll try that first, then maybe the 2 inch scaffold I have lying around.

One way or another though, my arches are going to be wider today than when they woke up this morning. lol.
Lawrence Slater

Thanks bernie, just caught your post a'fore I disappear to do the damage. :)

OK, thanks. That's pretty cheap and doesn't sound too complicated either. So if I don't like the results of the widended sq arches I think I will follow your Fiesta mod.

What model Fiesta had those arches? Did you use an 80's or 90's model?
Lawrence Slater

I decided that rolling a length of pipe along the arch sounded more elegant than the brute force of a jack and lump of wood. Heh heh.

So, here are the tools I used to butcher my wheel arch. :)

The thin black tube is a length of hard wall 20mm plastic conduit, with a bending spring inserted to stop it being crushed.

The chrome is a 1.4 inch motor bike front fork.

The grey one is a 1.9 inch length of scaffold tube.

Now for the fun.


Lawrence Slater

And here is the action and the result. lol.

The method I employed was to jack up the car, and insert the pipe. Then I rotated the wheel, which caused the pipe to roll along the inside of the wheel arch. I also inflated to 35psi.

First though, I inserted the black plastic tube into the recess in the w/arch, so that the large tube didn't push on the lip of the arch. (Hence the inserted spring to stop the plastic deforming).

After a couple of runs, when the chrome pipe was holding the arch away from the wheel, I inserted the scaffold tube and gave that a couple of passes.

As you can see, my paint suffered a little. I'm not surprised. LOL.

That was the nearside. The offside didn't crack paint at all. Again not a surprise, as it's in much better condition.

Actually it's a good result, I was expecting much worse. It's easily repaired. And I've now got a good 1 inch gap between my tyre and the arch. Plenty of room for a wider wheel.

In the long term though I am going to convert to rwa, and use the Fiesta arches for cheapness. Since my nearside w/arch really needs replacing anyway, I reckon I might as well go rwa.




Lawrence Slater

Lawerance

That looks great, did you try a heat gun on the paint to soften it, im inspired to do mine now....like you just as a temp measure until i do the rwa conversion


How much gap do you have from the wheel and the fender lip

Good job
Prop
Prop

Prop.

Thanks for the compliment. You must be as blind as me if you think that looks good ha ha ha.

Seriously though. I've discovered that it's not just the gap between the wheel/tyre and w/arch lip that matters per se, when measuring this.

It's the distance from the w/arch lip, to the chassis behind the rear side of the road wheel, combined with the offset of the wheel you fit. I'll get a photo with a tape measure it will make it clearer.

The reason I say this, is because many wheels have a different offset.

The ROUGH answer to your question about my gap now is ------ I'm running 4.5 inch Rostyles with 165/70/13 tyres fitted. With those I NOW have about a 1.25 inch gap w/arch lip to tyre wall, after pushing the arches out. I had far less before doing the deed.

Also my road springs are somewhat flat, and that makes a difference too, as it determines where the wall of the tyre is, in relation to the w/arch lip. And of course that varies when the suspension moves.

The original steel wheels I bought (I'm getting these banded), have a different offset. When banded to 4.5 inches, I think the gap to the w/arch lip will be about 0.75 of an inch, with the same size tyre fitted.

This is because these wheels sit further out than the Rostyles due to their offset. It's like fitting a wheel spacer. So even though the steel wheels will be 4.5 inches wide, the same as the Rostyles, the track between the wheels will be wider, and hence the wheels moved closer to the arches.

Oh, and no I didn't use a heat gun. I forgot. :)
Lawrence Slater

The other thing about using the pipe on sq arches, is that as the pipe reaches the middle of it's run, it pushes the w/arch out farther than at the ends.

It's obvious this will happen, but I didn't realise until I did it. It's not that pronounced, and doesn't look bad, but it is visible.

So on sq w/arches, if you want a perfectly flat line, best use wood/jack I think, or, just don't run the pipe the whole way across each time.

Instead start from one side, and just before reaching the middle, stop and reverse. Then start again from the other end of the w/arch. This should prevent the middle being pushed out more than the ends. (I think).
Lawrence Slater

I have tried this method twice now. The more recent was on a radically lowered VW Polo (Chav - style car, and no, it wasn't mine!) The thin panel single skin wheel arch stretched nicely and it worked very well and with no paint cracking. We used a small baseball bat,- maybe it was a rounders bat?

But on my square arched Sprite it was much less successful. It quite neatly folded the flange of the wheel arch lip upwards/ inwards and that helped. At first I thought it was also shaping the structural edge of the arch as well as it appeared to increase the clearance. But when I did the opposite side I realised that most of the effect was really just moving the whole body tub in relation to the axle! I think that the steel with the double skinning and shaping of the wheel arch lip is too rigid for it to work well. It did work on the front wings though as they are more flexible although on those I then had to modify the inner arch later.

But the real point is that the heaviest contact of the tyre on my car occurred up inside the wheel well, when the car was on full compression of the rear suspension. The edge of the arch isn't the problem - at least not if you fold the flange up. I used a scissor jack up inside the wheel arch and blocks of wood to direct the pressure where I wanted it and this was much more effective at spreading the inner arch to accept my tyre wheel combination. (165 65 13 on 5J rims)

Incidentally there are lots of U-tube clips on wheel arch rolling. Some very successful and a few horror stories!

Guy
Guy

After owning 4 RWA midgets i never thought i'd have a square arch.
I now think that all the adds claiming "rare and desireable RWA" are a bit over rated.
Square arches look far better in my opinion, especially with a fat tyre tucked up in the arch.
With some adjustment of the wheel arch and (and possibly a panhard rod) they can usually accommodate the wider tyre on a 13" rim
I eased the arches with a bottle jack and a piece of wood after the body and paint with no problems.



S G Macfarlane

Hi Guy.

Yup I discovered that. The double skin stopped the arch moving out. The inner skin just flexed and moved back again, or simply moved closer to the outer skin. And definitely the whole body moves in relation to the axle, soaking up some of the force against the w/arch.

But I still managed to deform the arch enough to make a difference.

The plastic tube I used with the spring insert, sits in the recess in the lip/flange, and at that point there is no gap between the inner and outer arch. So whatever force there is, moves the arch (once the body can't move anymore relative to the axle).

I found that if I pushed the pipe up too far into the arch, it just got caught and started gouging metal.

Something else I found today. My w/arches have "sprung" back again. Not that much, but enough to measure. Must be pretty set in their ways after so many years. I know plastic has a "memory, but didn't think sheet metal did. I'm now down to about a 1 inch clearance. So have lost about a 1/4 inch since yesterday. So I might have another go.

Maybe use the wood and jack method this time.

I bounced up and down on the rear wing with my hand partially inside the arch to see where the tyre contacts. And your right the upper inner arch is/can be the real problem.

I can't really do much more until I change my wheels. Until I get the steels banded, I won't know exactly where the tyres will rub (if at all now). I'm having an inch inserted in the outer rim. This will have the effect of making them 1/2 inch wider than the rostyles (as they have a different offset). As far as the outer rim is concerned anyway, and it's the outer rim that's the problem.

But that won't make the tyre move out by the same amount. So I'm just not exactly sure how much it will move out.

I might even band them to 5 inch. So I can't really be sure how far to deform the arches yet.

What size tyre is that SG?
Lawrence Slater

Hi Lawrence. Sorry for not coming back more quickly, I've been out all day trying to sort a fuel delivery problem on my Sprite.
The Fiesta repair panels are from the mk1 which started in the late 70s It's the one with the skinny chrome bumpers. Later models had bigger plastic bumpers and the rear arches had a kink in them to accomodate them so you can't use them. I looked on Ebay last night and there weren't any on there, but they do come up from time to time.

Bernie.
b higginson

its a 175 / 70 / 13 , although a 185 fits, its not the lip of the outer arch that restricts the clearance, the problem is the inner skin

When you jack the arch the lip does tend to rotate a bit

The arch does seem to spring back after jacking, i reckon i had to "over jack" by at least 1/2 an inch. Its a good job i had more bottle than the jack!!

Not sure of the methods described, but removing the wheel and jacking across the tub removes any doubts over axle movement.




S G Macfarlane

I run 185s on my square arch car

I too jacked the arch as much as I could and then had to shorten the axle at either side to get the wheel further inboard to the spring. I think I am about at the limit as my tyre almost touches the leaf spring and justs sits inside the inner arch
Robert (Bob) Midget Turbo

Pleased it turned out OK Carl.
FWIW, I'm running 175/60 Kuhmo's on my square arch car and the clearance from tyre wall to leaf spring is a bit over 1/2". In hard cornering the tyre deflection still produces rubbing on the spring.
M H Allen

SG.
I particularly like the contrast of blue body and grey garage floor. Very nice.

Well that confirms that I didn't imagine the creep back of the arches then, if it happened to others.

So really best to remove the lip altogether perhaps, and concentrate on making the inner skin closer to the outer skin. And the pipe method doesn't work as well on sq arches. When I try again, when I get my wheels banded, I'll shape a piece of wood specially for the task, and use a jack.

Thanks bernie. I'll take a peek in my local breakers and see if they have a scrap fiesta. I'm also wondering about just cutting out the arch and making it round, ala frogeye. They didn't have flares on the arches, so why do I need flares?

Following SG's comments about round wheel arches, I've been wondering why I like them.

I think one reason, is that the rear end looks like it's sagging, with the top of the wheel covered by the flat of the arch on the sq design. The other, is that a round arch is easier to get the wheel out. Less clearance needed. Both spurios.

I think it's really because I always wanted a frog, and a round rear w/arch is the closest I'm likely to get to owning one lol.





Lawrence Slater

This thread was discussed between 17/06/2008 and 25/09/2011

MG Midget and Sprite Technical index

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