Yeah, those are all the first gen Kelsey Hayes discs that Ford used on their passenger cars (like the ones above). I haven't been a fan of them due to their rarity, cost, and the fact that they're all 40+ years old. If I was going to try and update the front calipers, I'd go with something more like a Wilwood or CNC caliper, etc. Tough things are fitting them under 15" wheels (I still run 15s and plan to for the foreseeable future), the calipers are often wider than the WMS on the hubs, and the combined surface areas of the pistons are less than the area of one of the pistons in our single piston calipers (particularly the T-bird calipers). The only way I'd go much smaller on the piston areas would be if I upgraded the rotor diameters to keep an equivalent or higher brake torque. No rational reason to change - I still just dream of having them on the truck someday. Maybe I'll have to go to 17s someday so I can upgrade :-* .
Todd Z.
Your piston surface area scenario would be a fair comparison if...
On the single piston caliper, the pressure exerted against the brake pad had the load distributed evenly. It currently concentrates the pressure in the center of the pad, allowing the edges to flex and not put pressure against the whole surface of the pad. The opposite pad On the single piston caliper seems to support the brake pad a little better., but I think the single piston caliper could work better if it had support of the brake pad equal on both sides, giving more even coefficient of friction distributed among both pads.
I would think that four piston calipers, weather they be KH or another brand would do a better job distributing the load more evenly and efficiently across the backing of the brake pad thus giving a more positive or solid feel during braking.
Though the calipers are rare I think there are enough 65-69 lincoln and 66-67 thunderbird part support still out there to supply the need of the few who would like to try it. These older 40 year old parts will be more well taken care of and will not see the need for replacement any time soon if maintained properly. As far as fitting them under 15" wheels, Thats what all those older fords used back then. 15's are what Im using now and though it will be a tight package using 12" rotors, I still think It would be a fun, and rewarding challenge making it work.
I am willing to try and make the old KH calipers work with my 6-bolt spindles, and quite possibly come up with a viable alternative to Chevy brakes that would be All Ford on pre-disc Broncos. Not that DelcoMoraine isnt an excellent product. I just dont want to deal with the embarassment of asking for chevy parts at the parts counter in order to keep my Ford running :-[ .
Someone went to a lot of trouble to put them on Doug’s parts vehicle. It would be nice to see if it’s worth the effort.
Todd, all your points are well taken, and I thank you for your insight.
~Howard~