• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Rotor Thickness - A few Q's

Share this page

vping

vping

Yoda
Silver
Country flag
Offline
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?
 
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.
 
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.
 
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.
 
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.
 
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.
 
1965_MGB said:
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.
Click to expand...

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.
 
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!
 
Nothing wrong with Brembo rotors. I've put 'em on the Benz, the Alfa and the B.
 
billspohn said:
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.
billspohn said:
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.
Click to expand...
Click to expand...
 
Are the Brembo's USA? I'm leaning towards new when I get to that part of the awakening.
 
Brembo's are manufactured in Sweden, France, and the USA.
 
Quote him a price in a PM, Tony.

It just makes sense, Vince. You'll see.
 
I can do that.
 
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.
 
Back
Top