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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Concentric Clutch

I know that Guy did his from the Fiesta (I think)...

But has anyone got the part number for the Burton kit (Daniel, at a guess....)
Toby Anscombe

https://www.burtonpower.com/product_main.aspx?home.aspx

fergoddsake have you ever seen those prices

you could buy a lathe for less and make your own

maybe

APC10 £200
APC6B £33.19

Spacers to adapt the fit inside bell housing

£15 to £23 according to requirements

or for once do it our way!
Bill

do it yourself you lazy southerner.
Ebay item: 220309137443
Spacers from Burton: maybe £20-£30.
Make your own pipes up.
And there you go.

If I can do it, you can!
Tarquin

Ok, I didnt realise it was so much..

Last time I looked it was about £100 for the main part and £15 for a spacer...

Ebay here we come...lets hope its a quiet day in the office ;-)
Toby Anscombe

my dollop of ally billet, eight inches long four or five inches diameter

£8.00

couple of hours with lathe after measuring for distance for spacer

CSC nose on ebay £5.00 (Burton one)

CSC Parts For Saab £36

thrust bearing for Saab £16

Ally welding to change threaded hole location on nosepiece (specialist geezer) £5.00






Bill

APC is for the T5.

Clutch mount is APC6B £38.17

Nose is APC5 £80.74

Bearing is HD4941 £23.48

Spacer 1/2" APC7D £19.56

Feed and bleed hose lines APC8 £35.13 though you're better off with a shorter line than what comes with this kit

£197.08 all in + P&P though you're probably near enough to collect.

Or how much is Bill's time per hour???
Daniel Thirteen-Twelve

Fiesta hydraulic thrust unit £29.00
Block of aluminium for mount £5.00
Sundry pipe fittings £5.00

I gave myself a special discount on the time and did it as a freebie.

Guy
Guy Weller

biggest cost for me is the alloy mounting block. £30 for that plus I will need a spacer, around £20. I haven't got a lathe to play with or I'd do it myself!
Tarquin

If you go for the Ford one, make sure it's like this, with removable fluid pipe & bleed nipples.
People may send you the latest version which has them fixed to the body.


Tarquin

Tarqs, i called the Burton people and as Daniel said the APC 10 = 200 pounds(looks like you have) is for a t5 and wont fit a siera type 9.
They didnt tell me why it wouldnt fit but do some messurements to make sure or call them and ask why it wouldnt fit.

Im doing the APC5 list like Daniel, why?
Because its easy and (hopefully this one does actualy)works.
Only thing then is to worry what master/pedal cilinder needs to go with that set up so enough fluid is being moved to give the right travel and give a nice feeling on the pedall.
Hopefully the standard 1500 one(0.70 in) is sufficient(easy fitting and i already have one = bit cheaper)
Arie de Best

Hi Arie,

The simplest and cheapest solution to get the clutch travel ok is to make an adjustable master cylinder rod and shorten it.


All that’s required is a clevis fork end from Burton, part no: BRK007 and a clutch master cylinder push rod AAU 3469). cut the fork end off the standard rod and thread it 5/16 UNF. Then put a half height nut on the thread followed by the new Burton fork end. Adjust the length of the rod which will typicall need to be 3-4mm shorter from the tip to the clevis eye than the standard rod and then lock the nut against the fork end. Finally swap the shortened rod (which is of course adjustable) with the stock rod.
The result is that the clutch pedal now sits lower down and reaches the floor, thus limiting it's stroke, in a shorter distance than it does with a stock rod.
The bite is still at the top of the pedal of course but it feels much more comfortable to use.

I'd offer to thread a rod for you but I only have a 50% success rate in producing a good thread.

E-mail me if you want some photos along a with proof of purchase of my current book!
Daniel Thirteen-Twelve

Daniel, youve got mail!
Arie de Best

Arie, if you want to hold off on the Burton purchase till I've got my spacers here, I can check it all out for you. I've ordered the Type 9 mount and a 1/2" spacer. That gives me 35mm-ish total mount/spacer thickness (Burton told me the mount itself is 23mm thick).

I'll worry about the MC when the slave is in.

Toby, for info, 35mm is correct for my A series with flywheel packer (PM rear oil seal), and a Sierra clutch on skimmed midget flywheel. You'd need more spacer with a standard midget clutch, tho not sure you're using one. My Sierra clutch only just fits in the bellhousing tho, may need to get the angle grinder out to ensure enough clearance.

Will post pics when all the gear turns up.

Matt
Tarquin

Cheers Matt - is your clutch cover the Sierra one?

I might have to pause the csc till the next time the engine comes out. I have never really had a problem with the old one, the bearing is sound and as I built it myself I am sure that it will have to come out sooner or later ;-)
Toby Anscombe

Given the slave will produce a maximum of 25m of travel getting the right spacer is not critical though I'd expect 1/2 is about right but anything thicker would be too much.

Standard Spridget hydraulics produce 10mm of stroke and the maximum recommended for most if not all covers is 9mm.

So, a flat to the floor clutch pedal depression will always overstroke the cover until it fails.
Daniel Thirteen-Twelve

my pedal uses about ¾" travel in use

seems more like switching than stroking the clutch in and out

The next (?) time it comes out I intend whipping another ¼" off the packer I made, just to see if I can take some of the "switch" effect out of it so normal mortals (Gwyn...) can more easily drive it

I measured the distances needed quite crudely but as it did work then I left it alone...


Bill

And...

Rocket science? I can't do it, just crude measuring





I see I hadn't even taken he old (fairly new!) 1275 slave off when this was taken


Bill

Daniel,

I would be nice to know about actuation distance as I think they can vary considerably. As an example a mate put a 2nd hand 1700 Ford Xflow 135bhp in his Caterham including the HD clutch and the clutch actuation force went up considerably as did the actuation distance without any changes to the mechanism, the action is much more on off also so I don't think it's anything to do with the wavy spring leaves between the surfaces. I suspect to counter the higher clamping load the clutch fulcrum ring may be at a greater radius so requiring more movement of the clutch diaphragm fingers. The set-up currently can't be adjusted so the cable is unloaded the actuation travel increased so much. My mate is happy with that although I have warned him it's likely to knacker the thrust bearings and release bearing.
David Billington

When I did mine, I searched quite hard for data which would tell me the hydraulic ratio between the Ford concentric slave units, and the standard 1275 master. ie. how much fluid is moved by a single stroke at the master, and what distance of travel would result from this volume at the slave. I couldn't find any data that I could use to calculate this.

So, as I hadnt been able to find the data, in the end I just bought the Ford Fiesta slave and hoped for the best! When it arrived I connected the hydraulics with a rigged-up pipework to the slave bolted down to a flat plate on the bench. I was then able to measure actual movement which was about 10mm. I still wasn't sure if this would be enough but knowing that actually very little movement is needed to release a clutch I took the chance and went ahead with the installation. But it was all a bit of a gamble. I don't know if the "ratios" are the same for other ford slaves (mondeo etc)

In practice, the clutch is very progressive, using the full stroke of the pedal, and reasonably light. I think it is fully disengaging, although 1st and 2nd do grate if I am not careful. This could be clutch, but I rather think is down to worn synchros as the other gears are perfect. I think I am happy enough with the clutch operation itself.

Guy
Guy Weller

I had to go with 35mm total spacer otherwise the small projection on top of the slave contacts with a projection on the bellhousing (into which the gear selector rod projects). Guy, did you also notice this?

My measurements are at home, the slave has a travel of about 23mm, and the 35mm mount/spacer takes up about 12mm of this travel, leaving about 13mm of action.

Toby, yes the clutch is a standard sierra one, which I'm sure will be up to the job of my meagre A series. I did it due to cost of replacement type 9/midget clutch covers from MMOC. It's £25 for sierra cover and plate, comapared to about £80-£90 or more for the bespoke version.

I therefore have a bespoke version and roller release bearing surplus to requirements!
Tarquin

Guy, is the unit shown in attached picture the one that you use? If so is there an idiots guide to doing the mod, or would you be willing to write one?
Graham.


Graham P 1330 Frogeye

graham, don't use that one. Like I said, that extension to the slave gets in way of fitting it inside the bellhousing.
Unless of course you chop some of the bellhousing away.
Tarquin

Matt, I only asked cos Guy said he used a fiesta cylinder and thats the one I found first :) If not that one, then which particular one would be cheap and easy to fit?
Graham
Graham P 1330 Frogeye

Bill - sounds about right - a clutch switch!!

However, the only way the clutch can be tamed is to reduce the travel at the clutch slave in relation to the travel at the clutch pedal. The most obvious way to achieve this is to fit a clutch master cylinder of a smaller diameter or possibly have the existing one sleeved down. Or use a slave with a larger diameter (not an option with the Burton kit)

David - I don't have the actuation distance of the clutch cover I suspect it's nothing out of the ordinary because you only get the 'switch' like action when you fit the co-ax slave. I base this comment on my experience with the same clutch and flywheel with and without the co-ax.
Daniel Thirteen-Twelve

Daniel, I'm using Lara's original half-a-house brick double master cylinder of course. Do you think a change to separate masters would necessarily make a difference?

Or is it simply live with it, 'cos it works?
Bill

Daniel,
Read my post 7 messages above. The Fiesta slave and the 1275 (1971) master, by chance work together to give about 10mm of movement. If anything at all, this is slightly less than ideal and is certainly not likely to result in overthrow.
Ideally, one would obtain the displacement volumes of each, and calculate the resultant movement, but I couldn't find any published data.

Graham,
I suspect that there are two versions of the fiesta slave. The one you illustrate is no good as Tarquin says. The (possibly earlier) one to use does not have the rigid cast extension piece for the hydraulic connections. See photo. Or look for a SAAB one like Bill used. I suspect that the SAAB one is better made

Guy


Guy Weller

Bill,

The principles of hydraulics dictates that if you want less movement at the slave end of any hydraulic system you use a smaller master cylinder. Less movement at the slave end for any given master input gives a softer more progressive action on the clutch

I guess you have a clutch master bore of 7/8" or 22.2mm or is it 3/4"? Seems very large?

The later clutch master has a bore of approx 11/16 or about 18mm.

So YES - you'd have less of a switch using the smaller Clutch master assuming my understanding of hydraulics is correct and that the combined/house brick does have a larger master bore.

Guy,

I have read all your posts. My AP tech info states that the max travel the cover wants is 9mm and more than that will damage it. If a full stroke of the clutch pedal produces 10mm movement at the release bearing than you're over throwing an AP cover by 1mm. Given cover design isn't that much difference I think you have a potential problem.
Daniel Thirteen-Twelve

Sorry Daniel, I wasn't meaning to sound aggressive with that comment. Just wondered if you had ever come across any data on the Ford concentric slaves?

Guy
Guy Weller

Other clutch info I've just found states the never exceed throw is 0.42" which I think is smidgen over 10mm.

Daniel Thirteen-Twelve

Hi Guy, that's ok. Sadly I don't have any clutch data hydraulic info. I only know what the late type clutch slave on my car produced 10mm of travel on the Burton Co-ax. I measured this with the gearbox out of the car and the clutch co-ax piped in and fully bled (isn't it a dream to bleed!).

With everything back in the car I found the bit point of the clutch was right at the top of the pedal. Hence I made the shortened push rod which by moving the clutch pedal closer to the floor reduces the stroke and makes that bite point easier to manage as my leg is in a better position to be able to control it.

The real solution is a smaller clutch master or a larger clutch slave.
Daniel Thirteen-Twelve

Thanks Daniel

so to make sense of it I'd need to spend more dosh making a narrower master fit and fitting a later brake master too

At present that is a non starter so I will have to live with it I s'pose

cheers for the help.
Bill

Hi Bill,

Yes.

However, if your existing clutch master is 7/8 there is a kit (actually designed for the brake master) that will reduce it to 3/4.

If it's already 3/4 you could explore the viability of a special being made for 11/16.

Either might be cheaper and less trouble than modifying the car to take the later pedal box.
Daniel Thirteen-Twelve

cable it they either work or the dont , you can carry a spare cable with you so when it snaps 15 mins later its fixed i hate hydraulic clutches !! :-)
Darren 2 litre frogeye

Thanks Daniel

As I'm in a "no spend - unless!" year this year I'll live with what I have.

But my old (89) Sayab has decded to die, I may just whip its master off the bulkhead and have a play around

Just for fun of course....
Bill

Update on my solution.

Small obstacle in that I purchased the slave cylinder first, and I'm looking for parts that fit straight off. Burton don't do them as I've found!
I bought APC6A,, which is a replacement front cover for the type 9, but which allows you to fit a slave on the front. You can see in the Burton pic that the mounting holes for the slave cylinder are at 120 deg intervals, which suits their own slave APC5. However my slave is like the one in the kit APC10 (which is for the T5 not type 9), and the mounting holes are different. They do a spacer BH5MS which the OE Ford slave will mount to, but that is designed to fit to their own bellhousing.

So I will be making my own 1/2" spacer which will mount to the APC6A (using the 120 deg apart holes), and drill some extra holes for the Ford OE slave to mount to. Pretty easy I think.

That should definitely do the trick!
Tarquin

I had my Burton adapter off the dreaded eBay

About a fiver I think

the SAAB slave has the holes spaced two close together, one apart, so I had a local guy weld two blobs of ally in the right place (£5) took 'em home and filed flat and drilled and tapped to suit

you can see the two new holes in the picture of the modified carrier (nearest to each other, bottom and right)




Bill

Matt are you KEEPING a note of each measurement as you put the parts together

I measured and fitted and promptly mislaid all my scribbled notes and I would like a note of the relevant sizes of things from the front face of the type9 forwards to the clutch fingers. Mount depth, spacer depth CSC depth at rest and over the roller bearing face.


And back from the backplate on the A-series to the fingers on the clutch plate, including the PM spacer behind the flywheel

I'd forget my own head were it slightly looser than 'tis

I do have the spacer I made's measurements though if they will help anyone
Bill

I believe I sent Matt a pdf of a hand drawn sectional drawing of the parts I put together for this, with the dimensions that I used. At the moment I cannot find either the drawing, or the scan. So Bill is certainly not the only one with memory problems! Excess of Birthdays! Matt, do you still have that drawing?

Guy
Guy Weller

Ah yes brilliant Guy

I have just found your notes in the mail box

sent them back to you too for safekeeping
Bill

Thanks Bill It has arrived. The original scan is on my other (dead) laptop, so this is great. Another safe form of back-up!
Guy Weller

glad ta be of soiviss yerronner!
Bill

This thread was discussed between 11/01/2009 and 31/01/2009

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.