Rotor Thickness - A few Q's

[vping]

What is the minimum thickness you should go on your rotors. Car is a 74 and the are a little rusty. Not sure if they can be cut or not and want to mic them before I take them over to be cut.
Do you leave anything inside the hub when you bring it to the machinist?
Does it pay to have them cut or to just buy new?

 

[Nunyas]

no idea. The rotors always seemed to be rather thin to begin with, IMO. So, I've just replaced them without even considering having them cut.

 

[BritCarFan]

You have to look at the actual rotor. It will tell you the minimum allowable thickness (it's stamped in). The shop will measure this for you. The Napa Autoparts store here charges $10.00 per cut.

 

[gjoakes]

Usually 0.300" min thickness, 0.003" runout. Personally I have had so much trouble with longevity of turned rotors I don't even bother anymore. I just buy new.

 

[1965_MGB]

I worked in a parts store for about six years, and I can tell you that buying new rotors is the way to go. With the thickness being what it is, it really doesn't pay to try and skim them up. They are fairly cheap, and you know new ones will run true.

You can spend a few bucks and get some cross drilled and slotted rotors. I have a set of those, but have not put them on the car as yet. I figure they will look pretty cool through the wire wheels.

 

[vping]

Sounds good to me. I did nto check the price yet from Noss but should probably give my local Napa or autozone a call and see how much they offer them for.

 

[billspohn]

I worked in a parts store for about six years, and I can tell you that buying new rotors is the way to go. With the thickness being what it is, it really doesn't pay to try and skim them up. They are fairly cheap, and you know new ones will run true.

You can spend a few bucks and get some cross drilled and slotted rotors. I have a set of those, but have not put them on the car as yet. I figure they will look pretty cool through the wire wheels.

New rotors - half the new ones come with excessive run-out and have to be skimmed anyway. If you can skim the ones you have and not go under minimum, go for it, otherwise buy new - and check for run-out before installing them.

Crossdrilling and slotting - waste of money except to makes points with the easily impressed who don't know any better. Won't affect braking either way on a street car - unless you are unlucky enough to get an improperly drilled set that starts to crack from one of the holes.

 

[tony barnhill]

New rotors for an MGB are cheap - I keep them on the shelf - Brembo's...not even worth paying somebody to turn the old ones!

 

[DrEntropy]

Nothing wrong with Brembo rotors. I've put 'em on the Benz, the Alfa and the B.

 

[1965_MGB]

New rotors - half the new ones come with excessive run-out and have to be skimmed anyway. If you can skim the ones you have and not go under minimum, go for it, otherwise buy new - and check for run-out before installing them.

The store I worked in sold rotors by Wagner, most of them were made in the USA. We had a line of China made junkers that usually needed turning before they went out, but the US made stuff was right on the money.

As for the cross drilled comment, to each his own.

 

[vping]

Are the Brembo's USA? I'm leaning towards new when I get to that part of the awakening.

 

[tony barnhill]

Brembo's are manufactured in Sweden, France, and the USA.

 

[DrEntropy]

Quote him a price in a PM, Tony.

It just makes sense, Vince. You'll see.

 

[tony barnhill]

I can do that.

 

[vping]

I'm being tempted aren't I? I go the PM thanks. I've got to do a bunch of stuff first but you will be on my list when I get to that part.