The Dark Side: V8, V6 & 4 Cylinder Engine Conversions and related radical modifications (brakes, transmission, suspension, drivetrain) for MGB, MGA, Midget and all other MG models. Purists beware!
Has anyone succesfully re-drilled a 5 bolt rotor to a 4 bolt pattern? When I got my modifed 7.5" rear axle the drums had been re-drilled. I was wondering if this would be possible for the front also. It would open up a number of interesting possibilities.
Not that I've seen Larry, most front hubs aren't a full thickness all the way around the bolt pattern like the rear axle flanges and that would place studs in thin areas of the hub. I think that most guys are opting for new hubs like the ones Bill G sells that will take a 5 lug pattern and either original brakes as his first designs did or upgraded Wilwood discs.
Thanks Bill
Actually I'm trying to stay away from the 5 bolt pattern because I do not want to change the LE wheels Just some thoughts while I'm waitng on the snow to melt so I can get back out to the shop. Ahh - autumn in Colorado!!
I redrilled rear rotors from 5x4.5 to 4x4.5, using one of the original holes over. I figure the rotor seats on the hub center, so any slight problem with the holes will not be an issue. Would this work on the front, given that the rotor isn't a hat but bolts to the rear of the hub? I guess you'd have to be exact with the drilling, and you'd have to figure out an exact mounting for a different caliper.
I can echo Ryan's post. I've had 5 on 4.5" BC (Ford) rear rotors drilled for 4 on 4.5" BC - so, for this particular design rotor, we know that it can be modified. However, I'm guessing that some design rotors will not be candidates for the rework.
Larry
You can buy the LE style wheels as a 5 bolt pattern if that is what is holding you up. I think I still have the link at home if you're interested.
Lee
Thanks but I would have to change out the rear axles and I dont want to do that along with getting new wheels.. Just looking into other possibilities for the front.
I have drilled the Ford 8" rear to mate with late model discs from a 90`s stang to fit with the 4 on 4.5 B wheel! a little messing around but did it in my garage
Larry, take a good look at the MGB hub. You will see that you also have 4 other holes for the rotor, I think this may be in your way.
Bill is right about the MGB front hub. You could use Mustang,Falcon,Comet 67-70 6 cyl 4 lug hubs-same bearings and pattern as MGB. Scarebird makes a kit to put discs on the early drum 4 bolt hubs. It uses Mid 80's Nissan Sentra rotors and mid 80's Chevy Cavalier calipers. The hub has to be turned down a little for the rotor to slip on. It also works with 14" wheels.
Here is a picture on a Falcon:
Jim...
"You could use Mustang,Falcon,Comet 67-70 6 cyl 4 lug hubs-same bearings and pattern as MGB'
these bolt on the front of an MGB??
Jim
Thats the kind of information I am looking for. Does the Scarebird kit fit on the MGB hubs or do you need the Ford hubs for it to work? Also that rotor is about 1.4 inches smaller in diameter that is currently on the MG.
Bill
What would having 8 holes in the hub have to do with drilling a 5 hole rotor to a 4 hole pattern? I think I am missing something here
The rotor bolt holes would not let you drill the desire bolt pattern. Bad, bad bolt holes:moody:
Adapting other hubs have a price. One is alingment of the rotor (offset) This can cause the early bearing failure. Also caliper alignment in reference to rotor.
There is few hidden things that need attention.
I have used Chevy rotors, Honda etc. they do work but....:eyeroll: keep safety in mind.
Larry and Marty, The Sentra rotor is only 10" but vented.The Falcon and early Mustang guys don't have much of a choice. You could turn down the outside diameter of the MGB hub and use a Nissan slip on rotor that is larger diameter(10.5"-11")like the 240sx or Altima. The 4x4.5 pattern is pretty common,but watch the rotor offset. You would be on your own as far as caliper brakets and calipers.The Toyota 4 Runner calipers are popular with the Z cars. I used the early Mustang V8 hub on mine because I wanted the 5 bolt pattern. I lost about 1/2" trackwidth per side.The early 4lug(63-66)6 cyl Ford Falcon Etc. had smaller diameter spindles. In 67-70 they used the same spindle as the V8 with the same bearings as MGB.The Scarebird setup was just an example. I found with my setup the best studs were the ones meant for the Rotor which were Metric 12x1.5.I do agree with Bill on the safety aspect. Heck, I probably agree with Bill 99% of the time! I hope I answered everyones questions.
