MG Sports Cars

Found this article on the Cobra forum on how to install chevy rotors on the MG.

[www.clubcobra.com]

This is similar to how the rotors were modified on my Cobra MGB-IFS that is now on the Roadmaster. I do recall however, that instead of boring out the inner hub bearing bore, I used a narrower bearing race.

Arthur
-------------------------------------------------------------------------------------------------------------------------------------------------

For those of your that have MG spindles on your front suspension and have been saddled with a cross section of donor parts, those days are done. You can get a modified Wilwood kit from the UK, or you can do it your self.

I have been fighting with the brakes since I got the car. I am now near the end!

Buy the kit that fits virtually every chevy built in 69 and 70. Specifically a 69 camaro comes to mind. I got mine with 10.75 vented rotors and dynalite billet calipers for about $600 from jegs.

I can easily go with a bigger rotor (12" is about max on 15" rims) if I like but I started with the one that was provided.

You will need to have the hubs and inner bearing spacer modified. Mock yours up first but here is what I have to do to mine:
- move the inner bearing race outward 1/8"
- mill 1/8" off the back of the hub to maintain spindle clearence
- move the inner bearing seal out 1/8"
- reduce the O.D. of the inner bearing spacer for a good fit on the new seal. Be sure that the inner bearing race on the bearing still makes full contact with the spacer. I took .100" off the OD.

The reason for these mods was that the hub when mounted left the outer bearing 1/8" out onto the threaded section of the spindle. It would have been easier and cheaper to move the out bearing inward but there is not enough material behind the out bearing to make that possible. Took my machine shop three hours because of the inner bearing spacer.

Now for caliper adaptor. I ordered two peices each of 6061-t6 bar stock from the Metal supermarket. 4.5x1.5 and 2x6.5 both .375 thick. This worked out well requiring only .030 to .050 shims to center perfect on the rotor. The small peice is nothing but a spacer the fits between the back of the spindle and the larger peice to which the caliper is bolted. You will bolt the caliper from the rotor side to larger piece and through the larger piece, through the smaller piece to the spindle. Picture it? Shim to fit at the spindle and not the caliper.

Take these four peices of metal and cut them to clear the caliper and drill your holes. The ones for the caliper where 1/2" and for the spindle 7/16". Press the steel inserts out of the caliper adaptors provided and press them into your new adaptor. Do not do this until you are satisfied with your fit. If you press them out you should not press them back into the same hole.

Couple of ready made russell lines and hard line adaptors and I was off.

The old 4 pot Girling caliper(any one need a set, bolt right on) had smaller 1.625 piston compared to the 1.75 for the Wilwood. So you will will now have more clamping force in the front. About a 16% difference. Adjusting your bias will be required. Odds are that a master cylinder change will not be required (largest cylinder you can get away with and still lock the tires on a centered balance bar).

CENTER YOUR BALANCE BAR. By that, I mean front to rear so that it does not bind in the bore when it is being pressed. Under moderate pressure (like pushing on the peddle by hand) make sure the bar is centered front to rear in the bore. Adjust the length of the pushrods to make this so. Lots of folks complain that adjusting the balance bar does nothing. reason is that is has bound in the bore and is now appling equal pressure to both cylinders. More fun is where under light pressure it is doing its job but under heavy pressure it binds and your adjustment suddenly goes away. Think of the FUN

I still have not finished sorting out the brakes. The standard girling rears with EBC Greenstuff pads work fine for street and light track work. The front have never been better and I lost about 15 pounds on each wheel of unsprung weight (enough that I can tell a difference in the ride). I have to get longer pushrods and fit them then I will play with master cylinders until I am happy. If you want to know the particulars let me know and I will fill you in when they are done and tested.