|
|
|
|
| Author |
|
|
Registered
Join Date: Sep 2004
Posts: 3,650
|
Porsche rotors with CAST in holes?
There is a long thread going on over at Corner-Carvers about Porsche rotors with cast in holes. TCE is offering $200 for proof that the holes in the rotors are actually cast in and not drilled.
Here is the link: http://corner-carvers.com/forums/showthread.php?t=21273 The prize is actually up to $250. The thread is approaching 5000 views and nobody has been able to prove that the holes in the rotors are actually cast in. If you are not a member you will need to register with Corner-Carvers to view the pictures. If anyone can dig up the proof I suspect a Pelicanite can do it! -Kaefer |
||
04-04-2005, 04:02 PM
|
|
|
Registered
Join Date: Jan 2005
Location: Atlanta, GA
Posts: 1,392
|
Interesting.
Even before I was into Porsches I remember hearing that drilled rotors can lead to cracking, unless they were Porsches rotors which were cast with holes. Maybe an urban legend... |
||
|
04-04-2005, 04:14 PM
|
|
|
Administrator
Join Date: Feb 2000
Location: Los Angeles
Posts: 13,333
|
Porsche rotors (regardless of whether they're cast or drilled) crack just like all the rest.
__________________
Jack Olsen 1972 911 My new video about my garage. • A video from German TV about my 911 |
||
|
04-04-2005, 04:17 PM
|
|
|
Registered
Join Date: Sep 2004
Posts: 3,650
|
Quote:
Do rotors with cast in holes exist? Can this be proven, preferably with pictures of the casting process? -Kaefer |
||
|
04-04-2005, 04:28 PM
|
|
|
Registered
Join Date: Jan 2005
Location: Atlanta, GA
Posts: 1,392
|
Jack- indeed. I was just sharing what was common street talk.
I did find this article- http://www.gmhightechperformance.com/features/0503htp_speed/ "Adding stopping power to the front end is a set of 13.25-inch vented Porsche GT3 rotors and accompanying Brembo four piston calipers. While Brembo does not sell this kit on the open market, several companies sell these kits (which are the stock brakes on the Porsche 911 GT3) for F-bodies. These kits have become somewhat popular among F-body road racers because of its high strength rotors, which have cast holes preventing the cracking for which cross-drilled rotors have become infamous. " Is this proof? Well, probably not but its enough for me. Last edited by carnutzzz; 04-04-2005 at 04:34 PM.. |
||
|
04-04-2005, 04:29 PM
|
|
|
Registered
|
My drilled Brembo's were just replace because of cracking... I replaced them with ATE ?? I think.... they look like 2 Saturn rings around the rotor. No more drilled rotors for me.
__________________
Chad Plavan 911ST Race Car/2.5L SS Race Motor #02 1972 911T- Numbers matching- Restoring to stock 2011 Porsche Spyder Wht/Blk/Carbon Fiber Buckets/6-Speed (Sold) 2016 Elan NP01 Prototype racecar- Chassis #20, #02 |
||
|
04-04-2005, 04:34 PM
|
|
|
|
Registered
Join Date: Jan 2005
Location: Atlanta, GA
Posts: 1,392
|
Let's stay focused people. :-)
|
||
|
04-04-2005, 04:35 PM
|
|
|
Registered
Join Date: Sep 2004
Posts: 3,650
|
Quote:
The purpose of this thread is to try and find out if rotors with cast in holes actually exist. This info is worth $250 to the person who proves the rotors do exist. -Kaefer |
||
|
04-04-2005, 04:42 PM
|
|
|
Moderator
|
Movit
Quote:
__________________
Bill Verburg '76 Carrera 3.6RS(nee C3/hotrod), '95 993RS/CS(clone) | Pelican Home |Rennlist Wheels |Rennlist Brakes | |
||
|
04-04-2005, 05:06 PM
|
|
|
Senior Member
Join Date: Jun 2000
Location: N. Phoenix AZ USA
Posts: 28,943
|
Believe that I have a set in the garage. New in the box that are ready to go on the car when I get time, and the holes are not drilled but cast into the rotor.
JoeA
__________________
2013 Jag XF, 2002 Dodge Ram 2500 Cummins (the workhorse), 1992 Jaguar XJ S-3 V-12 VDP (one of only 100 examples made), 1969 Jaguar XJ (been in the family since new), 1985 911 Targa backdated to 1973 RS specs with a 3.6 shoehorned in the back, 1959 Austin Healey Sprite (former SCCA H-Prod), 1995 BMW R1100RSL, 1971 & '72 BMW R75/5 "Toaster," Ural Tourist w/sidecar, 1949 Aeronca Sedan / QB |
||
|
04-04-2005, 06:00 PM
|
|
|
Registered
Join Date: Nov 2004
Location: Greater Metropolitan Nimrod, Oregun
Posts: 10,040
|
Define "proof"....
__________________
"A man with his priorities so far out of whack doesn't deserve such a fine automobile." - Ferris Bueller's Day Off |
||
|
04-04-2005, 09:17 PM
|
|
|
3 restos WIP = psycho
Join Date: Feb 2005
Location: North of Exit 17
Posts: 7,665
|
The holes are cast. I remember reading it in Excellence when this tech was new. As for proof, that magazine disappeared a long time ago...
__________________
- 1965 911 - 1969 911S - 1980 911SC Targa - 1979 930 |
||
|
04-04-2005, 09:25 PM
|
|
|
Registered
Join Date: Jan 2004
Location: Pittsford, NY
Posts: 3,701
|
As I understand it, there are "dimples" that are cast where the holes are and then they are drilled perfectly afterwards. So I guess they are both cast and drilled.
__________________
Tony G 2000 Boxster S |
||
|
04-05-2005, 03:28 AM
|
|
|
Registered
Join Date: Aug 2002
Location: Galivants Ferry, SC
Posts: 10,550
|
Before this thread even surfaced....I openly questioned "what if" you drilled the holes...but carefully polished the inner surface of the holes with a cratex tip ( or such)...to mimimize the surface imperfections that lead to stress risers?
My point was that even the "cast" holes on OEM rotors are susceptible to craking simply by *being* holes. Having a smooth internal finish would...IMO....help dramatically in further crack propogation. ...no one here has yet to give a definitive answer to the question. Maybe time to EMail the OEM supplier directly? Anyone know the link address? Wil
__________________
Wil Ferch 85 Carrera ( gone, but not forgotten ) |
||
|
04-05-2005, 04:12 AM
|
|
|
Registered
Join Date: Sep 2004
Posts: 3,650
|
According to the thread on cc.com USA OEM Porsche rotors are made by Zimmermann:
http://www.otto-zimmermann.de/english/eng_framset.htm and Porsche OEM rotors (ROW perhaps?) are made by SHW: http://www.shw.de/englisch/21_automotive/24_bremsscheiben/fs_bremsschei.htm -Kaefer |
||
|
04-05-2005, 04:33 AM
|
|
|
Registered
Join Date: Jun 2001
Location: Sweden
Posts: 5,911
|
Cast or not, they crack just like the rest. I personally believe this "casting" thing to be an urban myth. It looks racey with dilled rotors but even Porsche themselves admint that it only helps "in rain". (it also helps them sell more rotors
 ):
__________________
Thank you for your time, |
||
|
04-05-2005, 04:55 AM
|
|
|
Registered
Join Date: Jun 2001
Location: Sweden
Posts: 5,911
|
Hihihih...*drum-roll* ... and and here are famous Porsche rotors with "cast-holes", made by Zimmerman (http://www.otto-zimmermann.de/english/eng_framset.htm):
 Oooopps...
__________________
Thank you for your time, Last edited by beepbeep; 04-05-2005 at 05:13 AM.. |
||
|
04-05-2005, 05:02 AM
|
|
|
Registered
Join Date: Aug 2002
Location: Galivants Ferry, SC
Posts: 10,550
|
Beepbeep...please go into detail...what are we looking at?
Wil
__________________
Wil Ferch 85 Carrera ( gone, but not forgotten ) |
||
|
04-05-2005, 05:04 AM
|
|
|
Registered
Join Date: Jun 2001
Location: Sweden
Posts: 5,911
|
Quote:
in second post , we are looking at picture from Zimmermans webpage, displaying CNC-drill hovering over what looks like blank 930 rotor (w/o any "cast ventilation holes")...
__________________
Thank you for your time, Last edited by beepbeep; 04-05-2005 at 05:17 AM.. |
||
|
04-05-2005, 05:12 AM
|
|
|
Registered
|
Is that Mill finishing the rotor surface? Is it beveling the inside diameter? Can't tell.
__________________
Warren & Ron, may you rest in Peace. |
||
|
04-05-2005, 05:20 AM
|
|
Mistress
Smurf
Craig (As in Craigslist)
1976 Porsche Carrera 3.0
1995 Porsche 993 Carrera Coupe
1985 Porsche 911 3.2 (Still in the stable)
1993 BMW 740 IL (Sold)
1985 Mercedes 380 SL (Sold)
1992 Harley Davidson Fatboy (Sold)
1971 Mercedes 280 SL (Currently being restored)
