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MG Midget and Sprite Technical - brake /clutch MC modifications
just searching for a revision company for my shaby 3/4 combined mc i have found small wilwood mc's at bargin prices (the 3/4 if available are pricy) now the idea of rebuilding the pedal box with those jumped in my mind They sell a 3/4 inch one so it could be easy but then i found a balancebar and started thinking hmm split brakes do not sound bad but when splitting the brakes i think the bore sizes should be reduced to keep the pedal and brake pressure at a good level anny idea's by how mutch? and front bigger than rear? |
Onno Könemann |
if you want split brakes and balancebar, go for a complete pedalbox from Koen at CCC in Nijmegen, or Peter May. |
David Smith |
Onno, I found a photo of this setup on line. It's made using the wilwood master cylinders and a modified later model Spridget pedal box which should bolt in place on your car. It uses 3/4" bore cylinders but you could easily modify the clutch side bracket and use a standard midget clutch master and slave to keep the effort as designed.
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Bill Young |
Another view as installed in the car.
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Bill Young |
Hey Onno, Here are 3 pics. of my master cly set up, I really love it, not a single problem scence install....it wasnt as easy as I thouht, but doable, secret...Measure, mesure, think about it Measure, measure...then cut I am looking forward to the MGB calipers with spitefire rotors later this year...that will truly make the brake system Defianatly one of my top 5 mods....BTW, get the masters that lay on the side instead of vertical like mine, they will fit much better. Prop http://tiltonracing.com/content.php?page=listb |
Prop |
and 2nd photo
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Prop |
sorry I cant jet the 3rd to pull up, but you get the idea of what I did. Yeah, your avg. oil leak in the engine bay....LOL Prop |
Prop |
You could fit a "Sebring" pedal box with separate brake / clutch master cylinders as fitted to Sebring Sprites. see www.sebringsprite.co.uk and then look under Archers Garage. They are a direct replacement for the early tandem master cylinders. Alternatively you could make your own as I have on a couple of occasions |
Alan Anstead |
if i deviate from std i want to build it my self and with 60 euro's for a willwood MC it realy seams doable the tilton setup lovely as it is is expensive with 200 dollar for the pedals and then 90 for each MC the archers garage is one is nice but has not seperated front and rear (and is not cheap either) |
Onno Könemann |
Onno I can assure you, this wont be a cheap mod, or a fast mod, I think building it yourself is vary ambitious idea.... do-able with enough imagination?? YES, money saving...??? Extremely Doulbtful!.....expect a good $500 to $1000 to do this weather you make it from scratch or build it from a completely modifiable kit....remember, there are no installation instructions....so the ability to adjust the idea on the fly and think 5 moves ahead is essential...which you have the ability, but Id advise ...dont under estimate the complexity or what is involved in this project You need to really beef this thing up, and think about the structurla integerity of your design, this thing is going to get alot of abuse, and leverages alot of various forces....add to the fact the metal this assembly attaches to is fairly thin, so that will need to be taken into account...whoever devoloped the spridget assembly, was a geniuss from that era, becuase it gets SO much strength from the bends in the assembly frame. I personally would strongly consider a pre-made assembly box/pedals that you can modify to fit the wilwood cly. that would certianly put you well ahead and ensure a strong box your going to need BTW on the tilton cly. that cost $90 thats for the entire cly. kit to fit all and any applications which comes with 3 differant resiviors lots of differant connections...you can buy just the cly. for around $45 and buy just the resivores you need Tilton also has 5 differant cly for various applications...I used a middle of the road, not the cheapest, and not the best. BUT I cant tell you how happy I am that I did this mod, Id do it agian every time even if it cost me a $1000 to do it agian, its just so nice to have a firm pedal, that works every time and has needed no maintance....As far as I am concerned its already paid for itself, and is paying big dividends, in stoping power, non-needed maintance, and trouble free supiorior operation (thats the big payoff) I simply cant recommend this modification enough...if its done right Prop |
Prop |
Onno, you've done your shopping I see. Over here the price for Tilton or Wilwood cylinders varies a bit. The cheapest I've found so far is around $68 US for a Wilwood universal cylinder which is visually identicalt to the Tilton unit Prop used. With the modified pedal box that I posted the photo of you'd just need two of those plus a weld on bias bar for another $60 and use a stock MG clutch slave cylinder (breakers or swap meet, cost?) and you would be in business. I figure I can build mine for around $250 US but I already have the clutch master on my car. A friend has already donated a spare pedal box assembly so I can build it off the car and then do a quick change over when I'm ready. I'll have to rebend and reflare some lines, not a big deal there. In your case you'll have to run a second line at least down to the original T union location and then splice in from there. Your choice which line the brake switch goes in, I'd choose the front side. |
Bill Young |
Actually Bill, You will want to get rid of that brass 4 way perporanting valve, or it will really screw up your braking ...on the front you want a 2 way spliter to go to the front 2 brakes and the rear are already split at the back axle .... I found that using stainless steel braded lines with AN fittings was the easiest way to hook up the M.cly. to the brake pipes, but if you got the cash Id replace all the lines with the SS braided line stuff. Prop |
Prop |
That is wat i was thinking about two Bill Getting a spare asembly and building it on that but with a willwood Clutch mc as well because than you would use 3 thes ame cylinders (handy if something brakes down or needs rebuilding) 3x €60.- =€180.- for the cylinders 1x €68.- =€68.- for the balance bar than a used pedal box and some welding machining and steel (done "in house") and at €250/300.- it could be done so prop why do you think it should cost more? the normal pedal box is usualy up to it so a moded one should be fine but i have found a company witch can sel me a new 3/4 dual mc at €250.- incl shiping.... |
Onno Könemann |
Prop, it's not a proportioning valve, simply a shuttle valve that moves one direction or the other if the pressure is more than a preset difference such as would be the case if the front or rear brakes sprung a leak. The fluid won't transfer from one side to the other, so it can be left intact as is without harm. On my car all the lines except for the two hard lines that run from the brake master cylinder to the brake fail switch are already braided stainless. All I will need to do is rebend the two existing hard lines enought to fit the new master cylinders. My clutch master already has a braided line directly to the slave cylinder so it will move over easily. |
Bill Young |
Onno, Why not use the newly available 7/8 combined master for about 150 euro's? I did and no complaint ever since. If you want to batter a pedalframe from a later twinsetup please mail me I have a spare. Thats the one I got from an other BBS member before I decided to install the 7/8 master. Bas |
Bas Timmermans |
Hey Bill, I thought that was a preportioning valve but yes yo are correct in how it works, When I did this mod, I was fearful how that shuttle valve would effect the brakes if it malfuntioned, so i took it completly out of play by eliminating it, this way one master cly opperates ONLY the front and the 2nd only operates the rear brakes, then I set the proportion bar to to 85/15 and ran in up and down the street slaming on the brakes till I was happy with how the braking occured...I think Im closer to 90/10 to be honeest Welding 2 pedal boxes wont work it will be to wide But a modified origial peddle box is a great idea, that would maintain the structral strength that will be nessary...To add my own 2 cents I wonder if you cant have the 2 brake cly. inside main box and use some heavy 3 inch angle iron 1/8th to 1/4 inch thick and weld it up into a frame on the far outside of the peddle box for the clutch master cly. By putting an addition onto the outside for the clutch would have a better chance of fitting and you would be able to use ALL the original bolt down holes and not need to beef up the area the box is setting up on. most likely need a after market brake signall switch. Thats the direction I would look into...the reason for the "Thick" angle iron? strength unless you you know how to bend sheet metal for strength, I wouldnt risk it, it wont be an issue to over build and be safe plus it would make it easier to build in the long run. Onno, Id figure in a good $200 extra, this is such a funky mod, it will really test your creativity, and you will find your self spending $15 a trip for 9 trip a day for every little pittle thing that you dont even currently know that exist Agian the best advise I can give having been there is look at it, look at it, look at it, Then measure, measure, measure, then look some more and you want to do this from every angle before making your 1st cut... there is alot of geo to think about BUT I think just modifiying the original peddle box is a great idea to save both time and money as well as some frustration...as long as you take into account the "width"...thats going to be the hang up, you notice in my photo how i had to notch the bonnet and wing rain channel and still have only minimal spacing next to the gas pedal...but a little grinding action on the side of the brake peddle gave me the needed space |
Prop |
DUH!!! I forgot one element of the design I plowed thur in the pervious thread, inorder to use the aftermarket master cly. wilwood tilton ect. you will need to figure out a way for all 3 Master cly. to sit level...maybe remake that back wall at an angle so when the 3cly. bolt in they will be sitting horizontial....other wise they will be sitting a good 15 to 30 degrees in a downward sloping direction....thats what I mean, look at it, look at it, and measure, measure, measure. You will also have to take into account adding some hieth to where the 3 cly. bolt into, or you will run into trouble with the brake lines bolt into the back of the cly. becausee the angle of the base will intersect with the back of the master cly at some point... Also you will need to devise a box to cover the peddle box and the master cly. the holes for the peddles act as a vacume and sucks heat straight into the area on top of your knees for a good ole bake off...thats why I modified a baking pan with a wearher door seal to reamady that issue. just some extra thought to kick around...let me know if I can be any futher source of negitive info and spirtit....LOL Sorry I dont meam to be so negitive...I really do think its a great idea...it just need a little "sanding off the edges" but still a great idea and well worth persuing Prop |
Prop |
wel i've got a spare cup lying around that wil help me through the sumer but after that i wil be building my own! If i wil use an early or late pedal box i have to investigate (does the late style fit in a mkII without hacking?) i imagine that i wil mount the mc's paralel to the top of the footwel (like the late style) i might have to ofset the clutch mc to keep it from clashing with the twin brake mc's and balance bar but that is doable bit of alu sheet to fabrikate a cover (or not nice in winter time) |
Onno Könemann |
>>>(does the late style fit in a mkII without hacking?) 'fraid not, no. |
David Smith |
Onno if you have the pedalbox with the dual master the later pedalbox need some cutting. Unfortunatey there is some reinforcement just where you want to cut:-( |
Bas Timmermans |
than the hunt jusr became easyer one old style pedal box it is! my midget is in no way original but it has not been hacked so no unreversable mods for me |
Onno Könemann |
This thread was discussed between 23/04/2009 and 26/04/2009
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