Rotors available (for now) for K-H disc brake cars

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jim-dawg said:
I got my sbp kh front rotors for my 67 formula S from Atlas through Moparmall.

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Have you checked the dimensions of the "hat" top and bottom? If so, please post the dimensions on the list. Don't make the same mistake I did, you may want to confirm they fit before you have them pressed onto the hubs, See my post #47 above for dimensions of an old one that fit.
 
ir3333 said:
Glad this popped up again.
...has anybody had caliper boot interference with new rotors that come with the hubs and hats machined?
I dug mine out and they are completely machined.
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Are you saying you have new early KH rotors that are one piece hub and rotor? Where did you get these? Have you measured them to compare with originals?
 
Cuda Al said:
I think you meant to quote @mobileparts
I suspect he has the rotor only for the early KH setup, you'd still need the hub.


Alan
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Cuda Al, No I was not mistaken. jr333 wrote "new rotors that come with the hubs and hats machined" . I read that as one piece, like a modern rotor. I don't see any reason to machine the hub on an early KH rotor/hub assembly. Unless he meant rotor/hat, not hub.
 
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yup, guilty as charged. I just meant the hat / hub section on the rotor...not the separate hub.
i don't have anything accurate enough to measure 6.596 or 5.942 or whatever?
for what it's worth it's ir3333. ir ....i'm retired!
 
ir3333 said:
yup, guilty as charged. I just meant the hat / hub section on the rotor...not the separate hub.
i don't have anything accurate enough to measure 6.596 or 5.942 or whatever?
for what it's worth it's ir3333. ir ....i'm retired!
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ir3333, Thanks for clarifying. Before you have your rotors pressed onto your hubs though, you may want to borrow or buy a caliper to check. I got this one from Amazon and I use it all the time.

NEIKO 01408A 8” Electronic Digital Caliper Extra Large Display | 0-8 Inches | Inch/Fractions/Millimeter Conversion | Polished Stainless Steel $39.95​


I tried posting a link to the Amazon site but the server stripped it. Great tool to have.
 
i do have 6" vernier calipers and never thought of measuring from the top.
Anyway my rotors are 5.96" at the top and BJ's are 5.942" so i'm close?
My caliper jaws are not deep enough or wide enough to measure the hat at the bottom.
 
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ir3333 said:
has anybody had caliper boot interference with new rotors that come with the hubs and hats machined?
I dug mine out and they are completely machined.
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Yep, I ran into this with the calipers and rotors that I got from Rock Auto about a year ago. The rough cast hats rode on the caliper piston boot. I took them to to a place that turns rotors and they were able to set their machine up to turn down the surface of the hat a bit so that they clear. End of problem.
 
ir3333 said:
i do have 6" vernier calipers and never thought of measuring from the top.
Anyway my rotors are 5.96" at the top and BJ's are 5.942" so i'm close?
My caliper jaws are not deep enough or wide enough to measure the hat at the bottom.
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Well, the top is pretty much the same as my original rotor, so that's good. But, it all depends on how wide the taper is at the bottom as well. I just went out to the shop to check the new rotors (that rub) that are pressed onto the hub. Unfortunately, I can't get an accurate reading because the hub gets in the way of the calipers, and the caliper arms are too short to reach the hat over the hub. Maybe I should have bought an even bigger caliper from Amazon!
 
As are my 6" measuring calipers. I went back and re-read all the posts and it seems the newer fully machined
rotors do not rub the caliper boots. Were your new rotors that rubbed on the hats "as cast" or machined?
 
ir3333 said:
As are my 6" measuring calipers. I went back and re-read all the posts and it seems the newer fully machined
rotors do not rub the caliper boots. Were your new rotors that rubbed on the hats "as cast" or machined?
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Mine appear to be machined. Here is a picture of the rotor (from Rockauto) installed, and it rubs.

IMG_0302[1].JPG


IMG_0301[1].JPG
 
Tx...Got my rotors from 2 different sources, one of my new ones has that bezel at the top and one doesn't.
maybe only one of mine will interfere? I do have a friend with a brake lathe so i'll sort it out.
Thanks for everyones input!
 
Any new information on availability of new early KH rotors that actually fit without rubbing? I talked to some local shops and they don't want the liability of cutting down the hat to keep the calipers from rubbing on my Rock Auto sourced rotors. Machine shop rates are very high here too.
 
A follow-up on this thread. So...I purchased expensive ( $75 and $120 each) rotors from two additional vendors that both claimed to have the proper rotors for early A bodies and yes, they are "guaranteed to fit". Neither set fit, they rubbed the seals, and were returned.

Summit carries the Centric 121.63005 for $29.95 each, I ordered a pair:

Centric Parts 121.63005 Centric C-Tek Standard Brake Rotors | Summit Racing


This rotor appears to be the same as the others, including the above mentioned expensive rotors, and Rock Auto rotors. The dimensions are all pretty close as best I can tell. The restoration shop I'm using for body and paint has a machinist lathe they let me use, so I cut down the hat on both rotors about .075". I had to go that far to eliminate rubbing on the caliper seals. It is hard to measure the hat wall thickness, but I do have an outside caliper I was able to fish through a bolt hole, measure, remove and measure the gap. The cone (hat) wall was somewhere between .260" to .280" prior to cutting, depending on where it is measured. it's about .185" to .205" now, so I had to take off about a third of the wall thickness. Again, these dimensions are approximate because they are very difficult to measure. By the way, these are good rotors, I have a dial indicator and checked run out of the rotor face after installation; it was +/-.001". That's hard to beat.

I do have concerns about removing a third of the hat wall thickness, but since the hat only carries force when braking, is not a friction surface, does not support the wheel only the rotor, has safety been compromised? The failure mode I could envision would be under heavy braking, but I would think the wheel would lock up before the hat cracks. I am not a metallurgist or a machinist, although I did have take some classes in both areas in tech school. Is there a safety concern here? Comments welcome.

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pomonamissel said:
i've been buying bendx replacement rotors with no problems .
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Where did you get them? Have you actually installed them and confirmed they don't rub? I have a set of Bendix rotors here from Rock Auto I bought in 2020 and they rub the seals and the tip of the rotor.
 
I got Rock Auto rotors and turned them down, but only the fat area near the disc where the seals rub. 6000 miles on them so far without any issues. when judging thickness remember the the first stuff that you are removing is the rough casting surface and probably has less effect on strength.
 
str12-340 said:
I got Rock Auto rotors and turned them down, but only the fat area near the disc where the seals rub. 6000 miles on them so far without any issues. when judging thickness remember the the first stuff that you are removing is the rough casting surface and probably has less effect on strength.
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I thought about doing that, but my caliper tip was rubbing too. It was easier cutting the whole width of the hat. I did consider cutting grooves but got concerned about creating weak spots that could contribute to a crack. The Centric rotor I used has a machined hat, it wasn't a rough casting
 
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pomonamissel said:
i just went on line and bought them .
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"Online" could literally mean anywhere. What website did you buy them from? When? Did you actually install them on an A body factory KH setup? Did you check to see if the piston seals rubbed the hat once the calipers were bolted down?
 
just have the calipers rebuilt by a builder , or i've bought rebuilt ones on line , sorry there i go again with that online stuff , sorry . i just try always to find the good parts out there . yes i've run across that rubbing issue , those are mustang rotors blanks that some suppliers put the 4 bc in . but buying name brand parts helps . i start with used complete assembies , spindles , hubs , calipers , brackets , hoses , bolts . and clean up the parts and replace every thing as needed to have great working rebuilt discs . i'll have to look to see if i kept any info on the supplier .
 
pomonamissel said:
just have the calipers rebuilt by a builder , or i've bought rebuilt ones on line , sorry there i go again with that online stuff , sorry . i just try always to find the good parts out there . yes i've run across that rubbing issue , those are mustang rotors blanks that some suppliers put the 4 bc in . but buying name brand parts helps . i start with used complete assembies , spindles , hubs , calipers , brackets , hoses , bolts . and clean up the parts and replace every thing as needed to have great working rebuilt discs . i'll have to look to see if i kept any info on the supplier .
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So the solution to caliper seals rubbing on rotors is to get calipers rebuilt?
 
340sFastback said:
So the solution to caliper seals rubbing on rotors is to get calipers rebuilt?
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No rebuilding calipers doesn't solve the problem. The configuration of the "hat" of the new rotors is such that it just barely rubs the side of the seal and wears it away. Only clearancing the hat so that it doesn't rub the seal will fix this. As far as I can tell all the different rotor manufacturers have this problem even though their rotors are different from each other. I have been following this thread for a long time hoping to find a new rotor source that fits without work, but so far no luck...
 
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