5-lug Front Hubs?

[BlownMGB-V8]

I may need those. I bought the Outlaw calipers off ebay with 1-3/4" pistons and set up for a 1" rotor. But 1" rotors are about like finding hen's teeth so I'll either have to use spacers or mill them down for .81" rotors.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=350435669835&ssPageName=STRK:MEWAX:IT
But the pads might be expensive. Still have to get rotors too.

JB

[mgb260]

Jim,You Outlaw you! I think some of those use the same pads as Wilwood. You could copy the pads for stainless shims and use the .81" rotors or make spacers easily for the 1.25". 3" hat would be good for caliper clearance but might make rotor close to tie rod end. There are smaller ones available or Heim joint. Remember to use red Locktite on hat to rotor bolts. Or 88-94 C4 Corvette Heavy Duty 13" rotors are 1.1" thick but have a shallow hat for the 2 piston slider calipers. They are left and right different because of curved vanes. Heavy though(20lbs).Here are specs:

[BlownMGB-V8]

Yes I think they do use the Wilwood pads from what I've seen. There is a Sportsman class 1" rotor but it is just 10-1/2" diameter and not a bargain item, about $90 each plus the hats. This is why I got the calipers so cheap, $110 shipped for NOS. With good pads a 10-1/2" ventilated rotor is all the MG will ever need, still, if I can find a bargain on the rotors I may still be able to bring it in under $300 total which is in the ballpark of what we are shooting for with this thread and the other two. These calipers weigh around 3-1/2 lbs each plus pads so something in the neighborhood of 4-5 lbs ea.

For anyone using the stock rear brakes the RX7 caliper would be the way to go, or in an aftermarket 4 pot caliper a 1-1/2" piston size, either of which will have the same piston area as stock. For a disc brake rear axle I'd be looking for something with a 48 mm or 1.9" single piston caliper with built in e-brake or maybe a bit larger but not over 2.4" or 60 mm. There should be a stock caliper like that available.

At one time there was a Mitsubishi Eclipse (I think it was the '91 with the base engine) that used a nice rear caliper with an external allen wrench screw head to retract the piston but I only ever saw that caliper on one car. Very nice and super easy pad change. But the piston is too small so you'd need something from a larger car. For a somewhat smaller piston figure the percentage and go that much smaller on the front. The pedal would be firmer but more precise. NASCAR has gone to 1" pistons and high line pressures but go too far and you'll need a smaller master cylinder. The reason for using a single piston slider on the rear is that it allows the incorporation of the e-brake cable. Stay away from the type where you have to spin the piston back into the caliper. On those it's often easier to swap calipers than to screw the piston back in, even if you don't destroy the seals doing it, which is a definite risk. The reason for this is that the internal adjuster has nothing to keep it from spinning backwards so instead of screwing the threads back together everything just spins and even the smallest speck of dirt or rust will frustrate your efforts. I'd recommend a caliper if I could, I know there has to be a good one out there. It is inconceivable that the Mitsubishi design was only used in a limited application on one model, it really was very, very good. A pad change took all of about 5 minutes. Might be worth lunch with a Midas employee.

JB

[roverman]

Anybody ? "Wilwood" likes this process best, but NOT cross drilling ! The RX-7 rear caliper has built-in e-brake. Why not a" line loc", for those without,(including stealth, theft deturrent)?  roverman.

[MGBV8]

Art,

A line lock is not a legal parking brake most places.  I always used a block of wood on my Camaro.   ;-)

[socorob]

I was at a u pull it yard today and there was an rx7 turbo 2, so i got all the calipers off. What would be the issue of using the caliper withouta spacer for that .07 inch difference with a .81 caliper? Especially if you change it before it wears down to nothing. I know the pads wear down much more than that amount. The RX7 has some really nice calipers, these are very light for their size.

[mgb260]

Robbie, Spacers are easy, just copy the pads backplate. Stainless works good. .035 shim each side. You are right, as the pads wear the pistons can bind or pop out. What are you going to use for rear rotors?  The RX7 rear rotor is thinner than the front,20mm (.79) instead of 22mm..81 rotor and hat also. I don't think you need a shim there. When you get it all figured out should work excellent. Keep us posted.

[socorob]

Well, This will be a slow process as my car has working brakes. The only reason I got these now is I was there and they were available.  I already have rear discs, which are gm but i dont like them, with 1-1/4 rotors. I want to go with 10-3/4 in the front. Will probably keep my rear setup unless i have too large of a proportioning problem. Right now, I have a 3/4 master, so im not sure if that will work or if i will have to go to a 7/8 or 15/16.WIilwood has a .72 hat mounted rotor but is too large, like 11.66 for my 15 inch rims. There are still a lot of things I will have to work out, but im not in a hurry.http://wilwood.com/Rotors/RotorList1.aspx

[BlownMGB-V8]

.035" per side should be in the working range, it all depends on how much gap you have between the caliper and the rotor on each side, and the thickness of the backing plate. Obviously you don't want to wear the pads down to nothing but if you do, you don't want the side of the pad eating into the corner of the caliper, potentially ruining it. I think most backing plates run close to 3/16" thick so if the nominal running clearance isn't too much the extra .035 should be no problem. But the stainless shims make great heat shields (even better if you can get titanium).

I just scored a set of rotors and hats:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=140508353345
It'll take a little work to make them fit. But absolutely killer pieces, 13" x 1-1/4" ultra light ceramic coated Red Devil, probably steel alloy. Should come in around half the weight off a comparable rotor, I'll know more when they get here.

I'll have to redrill the hats, redrill my hubs, and either make or buy spacers for the calipers to widen them to the 1-1/4" size. Cost with shipping, about $118, a very good price for these parts. So I'm approaching $250 and with pads will be right close to $300 which is sort of the goal. And if it all works as planned I'll have the lightest and most effective brakes almost anyone could want, at a price almost anyone could afford. It helps that I can do some machine work myself, but hey, this is what we're shooting for here.

I've decided not to chase after aluminum hubs.... though you never know what might show up on ebay. Mine are very strong and well made, only needing re-drilled to go back on the car. So I'll be giving up a pound or two there. My target is a finished unsprung weight about the same as what I had before, and about the same as stock. Once the brakes are fitted and I know exactly what I want it'll be time to get in touch with Greg Smith at Weld and talk options. I may call Centerline too, it's hard for me to believe they don't have some sort of a plan in place to make 17" wheels.

JB

[mgb260]

Jim,Super trick rotors for cheap! Looking forward to the "How to do it". I think you won't have a problem with the rears over powering the front.  Even with the balance bar setup, if you have excessive pedal travel you may have to upsize your masters.

[mgb260]

Robbie, The .79-.81 is so close you could use the hat and rotor on the rear with no problem. For the front use a short hat behind the hub like stock. The only problem is the hats are all 5 lug. You could have a shop tig a ring over it and drill to your hub pattern. You would have to know somebody because if you have welding done on brakes or suspension parts, they either won't because of liability or the cost goes way up. That's why I comb through stock part interchange lists. The 86-88 Toyota Cressida rotor I'm using for the MGB kit is 10 3/4" diameter and 22mm thick vented  like the RX7. I think you will find the GM rears way too big. I plan on using 86-87 Acura Legend front sedan rotor,10.4" diameter and 20mm thick vented  like the RX7 for the rear kit.  Perfect  match. You could just drill your hub pattern between the 4 existing holes for the front and drill your wheel pattern between the 4 holes in the rear and slip on. Not knowing the hub diameter or axle diameter of your Alpine, may or may not have to be turned down to fit. You can get fancy slotted and drilled rotors also. On the master if you have excessive pedal travel move up to 7/8", again the same as RX7 Turbo II.

[rficalora]

Jim, where do you find stock part interchange lists?

[socorob]

I found a place that sold blank hats about a year ago when I was doing the rears. I can't remember if I saw it online or if I asked Wilwood if they can sell me one before the holes were drilled. I'll try to see if I can dig it up. I don't have power brakes so I'm worried about the pedal stiffness going up to 7/8 or 15/16 and not having a booster.

[socorob]

http://www.summitracing.com/parts/WIL-171-2234/
Summit sells the undrilled wilwood hats, but a year ago I found a different company that made them and ost less.

[mgb260]

Rob, not Robbie, Boy this is getting confusing. On Rockauto.com you can click on the blue stock# and it will tell you what years and models parts fit,very handy. Also Centric website for rotor dimensions.  Robbie, I had no idea you could buy the blank hats,remember to have the offset  so you have a minimum  of 1/4" to 3/8"steel to 1/2" for aluminum  caliper adapter. The 7/8" master is what the RX7 used. You don't need a booster. If too big you would get a hard pedal. You can try yours and if too much pedal travel go up then.

[BlownMGB-V8]

I'd like to know that other source for hats, I may need a pair. Aluminum?

JB

[socorob]

I don't remember what they were made of but j know they had blanks in all sizes. My computer crashed a few months ago, so looking through all my bookmarks last night, it seems I lost the site. I think I found them by searching for undrilled rotor hats or something along those lines.

[DC Townsend]

Most race suppliers sell undrilled hats in both aluminum and spun steel versions. The big guys like Pit Stop, Pegasus, and HRP World mostly sell Wilwood but look around at some of the more specialized outfits that cater to road racers. That said, the spun steel Wilwood hats come in an endless variety of hole spacings and off sets and at about $40-$45 each are an attractive option to aluminum and almost as light.

[mgb260]

David, Your car looks great! Unusual mix of old and new style. I think it would look even better if the rockers flared out to meet the fenders. Or side pipes like a Cobra. You might need wheel spacers to fill the fenders. How are the brakes coming?

[DC Townsend]

Jim,

Thanks for the props on the B. Going with side exhaust similar to LeMans cars so it will exit right in front of the rear wheel. Thought about the rocker flares and still may go that way or may save it for something to do after I'm on the road. I have a set of 1" spacers on hand (from previous project) that I can use if I need to move the front and rear tracks.

On the brake project, I have everything on hand (finally) and a complete write up (less photos) but have been giving my time to the B's bodywork while the weather has been warm (in the 30's for last 2 weekends). Funny how my build seems to revolve around the weather. The brake work is inside stuff (small work are in the basement) so I try and save it for when it's too cold to work in the garage. The new kerosene heater is a welcome addition and has really extended my ability to be in the garage but even it has limitations when the temps drop to zero.

[BlownMGB-V8]

Wow, it's almost scary how well the dimensions worked out. I still need to make spacers for the calipers and drill bolt circles but the caliper mounts are going to be dead simple it looks like. The hats that came with the rotors are 3.4" from the flange to the backside According to my calculations the new calipers will need to mount 3/8" (.363") inboard of the spindle mounting lugs. Couldn't get any simpler than that. I'll have to double check again of course but it looks right. They will also have to mount 1" outboard to accommodate the larger diameter. There is 2-3/8" on the front side so plenty of clearance there.

These rotors are a floating design mounted with about a dozen beefy fasteners. There is a floating block anchored by each SHCS that fits into a rotor slot. Weight is about 10 lbs with the hat. I dunno, NASCAR or something I guess. Extreme overkill for sure. Bill, over on MGE is going to have a cow when I tell him.

JB

Oh. Except for the tie rod ends. Knew it was too easy, the rotor is sitting 1/2" farther inboard this way. So a shallower hat, and close clearance on the wheels, or bend the steering arms inward. Hmmm.... decisions, decisions. Maybe a little of both and 1" thick aluminum mount adapters. After I remove the dust shields maybe I can get by with a 3" hat.

[mgb260]

Those darn tie rod ends. I ran into that several times trying stock part alternatives. I also thought , boy this is easy! That's what makes this fun, the challenge! I have a healthy respect for the factory engineers and still I have problems.

[MGBV8]

Heim ends instead of tie rod ends.

[BlownMGB-V8]

Nah, that doesn't help any.

JB

[roverman]

FWIW, I just completed aluminum, sleeve/spacer/adapter, to fit series II RX 7 hub on to Mustang II spindle. Using Ford outer bearing in Mazda outer cup. Welded beads on inner RX 7 cup, to drive it out,(no punch-out ports). Adapter holds the inner ford cup and moves it .700" away from outer bearing. Adapter also holds Mustang II inner seal.Yes, I could have bought a Wilwood brake conversion kit, for a lot more $'s, for less braking. What's the fun in that ? Dem's da brakes, roverman.