Boss T/A front brake upgrade (Lincoln/Tbird calipers) thread

[bnickel]

Ok, so here is a little progress. I was able to get the inner bearing I needed yesterday to mount the LTD rotor onto the Mustang spindle. The part that works is the standard drum inner wheel bearing, Timken Set6. The outer was even easier, I had the wheel bearing for it already as it was the out for the Mustang drum. Rock auto lists that as A1 for the part number, BCA/National.

So I've got the rotor mounted on the stand now. I tightened the nut down on the spindle and the rotor spins nice and freely. I'm going to try and get the fasteners I need today to bolt the brackets up to the spindle and see why they want you to drill the caliper, grind it and face the mounting ears.

I'm also going to try and find a race shop that stocks 2 piece rotors so I can try and match the drum hub with a set that has the same measurements as the LTD rotor so that we can use 1 bracket for everything.

I suppose I'll pull the splash shield off of my 67 in order to mock everything up properly. I'll provably do that next weekend.

any pics of the mockup so far? i'd like to see them if you do.

 

[Rusty67]

I'll take pics later today after my trip to the hardware store.

Also, I checked the part numbers for the inner seal and the part number for the LTD and the drum hub are exactly the same. So that should tie up the last of the loose end in that department.

 

[Rusty67]

So I've run into a minor problem. The brackets I was loaned wont fit over the rear of the hub on the rotor. I am going to try and flame cut some flanges next weekend with a large enough center hole and no mounting ears on them. From there I can space out the mounting ears I will need.

Pics:
brake brackets pictures by 300zeex - Photobucket

Also, I see why both Cobra Automotive as well as the other vendor say to face the caliper ears and drill out the threads. I Think I might be able to make the brackets work just fine without doing this. I will provably need a tap to clear out the thread all the way though the caliper body but no other modification of the calipers should be neccissary. I tried running the bolt all the way through without any success, it got stuck at the end.

 

[bnickel]

So I've run into a minor problem. The brackets I was loaned wont fit over the rear of the hub on the rotor. I am going to try and flame cut some flanges next weekend with a large enough center hole and no mounting ears on them. From there I can space out the mounting ears I will need.

Pics:
brake brackets pictures by 300zeex - Photobucket

Also, I see why both Cobra Automotive as well as the other vendor say to face the caliper ears and drill out the threads. I Think I might be able to make the brackets work just fine without doing this. I will provably need a tap to clear out the thread all the way though the caliper body but no other modification of the calipers should be neccissary. I tried running the bolt all the way through without any success, it got stuck at the end.

which rotor did you end up getting? is it the 71 LTD rotor like we were talking about? or did you use one from an earlier big t-bird? there are a couple of options here, you could either enlarge the holes on the bracets or machine to rotors as necessary. since these particular brackets aren't yours that makes modifying these brackets an issue, but if they were your brackets it wouldn't be a problem. i certainly wouldn't be concerned about doing it on some i owned, though a better fitting bracket/rotor combination would be preferable.

 

[Rusty67]

The rotor is the 70-72 LTD rotor. You could definately have the inner part of the rotor machined down to make it fit these brackets but there is still no garauntee the calipers would line up with the rotors using this bracket/rotor combo. There is just enough space to enlarge the hole in the bracket if so desired. Thats why I'm just going to make my own.

Part of the reason I wanted to see some already made brackets is that I wanted to understand why they want you to face the caliper and drill the threads out. I understand that now but I personally don't believe it is neccissary. I think the bracket can be made to bolt up the calipers without modification.

 

[bnickel]

The rotor is the 70-72 LTD rotor. You could definately have the inner part of the rotor machined down to make it fit these brackets but there is still no garauntee the calipers would line up with the rotors using this bracket/rotor combo. There is just enough space to enlarge the hole in the bracket if so desired. Thats why I'm just going to make my own.

Part of the reason I wanted to see some already made brackets is that I wanted to understand why they want you to face the caliper and drill the threads out. I understand that now but I personally don't believe it is neccissary. I think the bracket can be made to bolt up the calipers without modification.

i know that the one guy you talked about the brackets at one point said their kits used the 70-72 LTD rotors so i was under the impression that everything would be the same, apparently i shouldn't ass-u-me, but in any case if we get a set of brackets that has the smaller hole we can open the hole up a bit as needed, so really not that big of a deal.

 

[Rusty67]

The brackets I've got are the Cobra Automotive style so they use a Mustang hub and are machined for that which is why we are running into this problem. I'm not worried about it because it looks like there is enough space to enlarge the hole in a bracket and still have enough meat in the bracket for strength. Hopefully I can flame cut a blank this weekend at my friends shop.

 

[Helmantel]

Interesting to see that ABS powerbrakes now makes aluminum big KH calipers. I have they complete T/A setup, but it's still collecting dust on the shelf. At 389 bucks, they're not a bargain, but not extremely expensive either.

I wonder if they're a direct replacement for the Thunderbird calipers, because in that case, the mounted holes will be threaded and need to be drilled out. Not that big a deal though.

 

[Rusty67]

Not with the brackets I'm trying to make... if I can make them the way I think I can...

 

[redhorse65]

I've started and done this conversion on a 65 Coupe w. 65 V8 drum spindles/hubs, Wilwood Rotors, Cobra's brackets and hardware and machined T-bird calipers. Stopping power is very good, but the Wilwoods developed a shudder when warmed up. I was hoping for a 1 piece rotor like the LTD rotor for street use (the 6012 Raybestos rotor for 1969- T'birds doesn't work on the 65 Mustang V8 Drum spindle, too deep in the bearing well, and snout doesn't clear enough for the cotter pin even.). The 70-72 LTD Rotorpros rotor looks like it'll work, but what about bearings to put this rotor on the 65 V8 drum soindles. Can anyone help with that one? I'll be glad to give any spec or info on my otherwise successful conversion too. I did find that I can NOT make the 67 dust shields work w. this combo. Any help with the bearings would be greatly appreciated!

 

[redhorse65]

Re: interference with the caliper bracket: I also had the back of the 6012 rotor machined down equal to the OD of the 65 V8 drum hub so it would clear int othe opening in the bracket. Only problem still was the depth of the snout being too long f. the end of the spindle to clear enough. Will do the same to the LTD rotor if the bearings can be fig'd out. God-willing, if it works and bearings are doable, I'll post pics.

 

[Rusty67]

The 70-72 LTD Rotorpros rotor looks like it'll work, but what about bearings to put this rotor on the 65 V8 drum soindles. Can anyone help with that one?

Ok, so here is a little progress. I was able to get the inner bearing I needed yesterday to mount the LTD rotor onto the Mustang spindle. The part that works is the standard drum inner wheel bearing, Timken Set6. The outer was even easier, I had the wheel bearing for it already as it was the out for the Mustang drum. Rock auto lists that as A1 for the part number, BCA/National.

You said the 67 dust shield didn't work ? Why not ?

 

[redhorse65]

It just wouldn't clear the Cobra bracket without cutting it (shield) up. I elected not to since it doesn't see much wet/dirty use anyway. I thought the 69 spindles were different from the 65 V8 drum units? I see the LTD rotor needs A12 and A13 bearings, whereas my 65 drum hubs use A2 and A6. Does some combination of bearings and race work with the 65 drum spindles? That's what's got me mixed up. I'll try to get a photo tonight of the shield-bracket interference. Still have them in case I need regular GT brake setup. Any advice on bearings is still appreciated too! I'd love to get this to work once and for all.

 

[Rusty67]

Who is using a 69 spindle ?

The 65-67 V8 spindles are the same, drum or disc. I think 68 and 69 drum spindles are the same as well. I believe in 70 they switched to the larger bearing. I can't remember if it was 69 or 70 when they switched the bearing.

Just use drum inner and outer bearings for a 65 and the LTD rotor should mount up just fine on your 65 drum/disc spindle.

 

[redhorse65]

Is it just that simple- using the V8 drum hub bearings and the races that come w. the LTD rotors? I list A6 for inner and A2 for outer (A1 is for outer 6cyl), but still... that seems easy.

 

[redhorse65]

Holy cow- thanks for that info.

 

[redhorse65]

The Rotorpros LTD Rotor interferes with the caliper at the rotor hub. I ended up using the 69 T-Bird Rotor, but had to have the outer race machined for 5/16" more depth to clear the cotter pin slot, and had to have the inner side of the hub machined to clear the ID of the caliper bracket. Still waiting to drive it, but will post pics if it is successful.

 

[hivewax]

bringing this thread back from the dead... i went the easy route and bought the Cobra Auto big brake kit. i'd like to see where you got the aluminum calipers to fit these big brakes and if anyone has done the front swap to rear brake setup like the Boss T/As.

here's a video of the swap at Walt + Chip Hane's shop...
YouTube - Walt and Chip

 

[96 DOHC Cobra]

Somebody owes me 16 seconds of my life back.

 

[my427cobra]

I wouldn't worry too much about ease of maintainance. A decent quality rotor should last a long time, even on a daily driver and about forever on a weekend driver. If you plan on a lot of open track weekends of other sorts of racing, then I can understand that it becomes more important.

Anyway, here are some pictures and a drawing of the Cobra Automotive brackets. With a disc brake hub and a Raybestos 6008 rotor (68 Full Size Ford), and after I spot faced the mounting surface on the mounting ears of the caliper, I needed to move the caliper ~1/8" inboard with spacer rings, so the offset of the caliper mounting ears was not quite enough. They are probably correct for Cobra Automotive drum hub and Raybestos hat+rotor combo.

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Hi. Do you still have this bracket drawing available?

Cheers
Greg