|
|
|
|
| Author |
|
|
Registered
Join Date: Jan 2005
Location: cooperstown NY
Posts: 894
|
crank balancing / clutch ?
repost from the tech forum:
i'm doing my 72 e rebuild, a driver no tracking planned. its time to balance my crank. my pressure plate "looks" good no scoring. the body is aluminum, the plate is steel. questions: should i buy a clutch kit and replace all components? can i reuse my pressure plate instead and replace the throwout bearing only? is the aluminum body something special or standard to that type clutch? its starting to get expensive! all opinions welcome. thanks
__________________
bob 1972 E pos correction: expensive pos someday.... "shut up and drive!" |
||
03-02-2009, 04:03 PM
|
|
|
Registered
Join Date: Oct 2008
Location: Nash County, NC.
Posts: 8,505
|
The aluminum pressure plate is still an option but the fingers will show wear under the TOB. if you need a clutch disc, just replace the disc. Remember,if you cut the flywheel, youre actually cutting clutch life.
Why spend money on balancing a crank that has a factory balance? Any part that you bolt to it afterward has a zero balance built in. Bruce |
||
|
03-02-2009, 04:24 PM
|
|
|
up-fixing der car(ma)
|
Quote:
__________________
Scott Kinder kindersport @ gmail.com |
||
|
03-02-2009, 07:26 PM
|
|
|
Registered
Join Date: May 2003
Posts: 3,346
|
The aluminum pp is expensive and not standard in the kits. I would use your old one. I would replace the throw out bearing and the disc.
-Andy
__________________
72 Carrera RS replica, Spec 911 racer |
||
|
03-02-2009, 08:16 PM
|
|
|
Registered
Join Date: Oct 2008
Location: Nash County, NC.
Posts: 8,505
|
Article in UPFIXIN DE PORSCHE, Porsche Club condensing of tech articles circa 1972 basically stated all replacement rotational items for Porsche are zero balanced.
|
||
|
03-03-2009, 02:09 AM
|
|
|
up-fixing der car(ma)
|
I am playing devil's advocate; Porsche has a spec. of course and if it meets that, then fine. However, the spec. on rods is 9g delta, and depending on the balance machine, I have seen Porsche cranks that need a little tweaking. It's most likely "good enough" but is it zero?
__________________
Scott Kinder kindersport @ gmail.com |
||
|
03-03-2009, 11:06 AM
|
|
|
|
3 restos WIP = psycho
Join Date: Feb 2005
Location: North of Exit 17
Posts: 7,665
|
Quote:
__________________
- 1965 911 - 1969 911S - 1980 911SC Targa - 1979 930 |
||
|
03-03-2009, 12:40 PM
|
|
|
Moderator
Join Date: Dec 2001
Posts: 9,569
|
How do you get rid of a throw out bearing?
__________________
'66 911 #304065 Irischgruen ‘96 993 Carrera 2 Polarsilber '81 R65 Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13) Ex-'88 Carrera (Sold 3/29/02) Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04) Ex-'89 944 Turbo S (Sold 8/21/20) |
||
|
03-03-2009, 02:39 PM
|
|
|
Navin Johnson
Join Date: Mar 2002
Location: Wantagh, NY
Posts: 8,804
|
Quote:
t/o bearing and clutch disk are not included in balancing procedures. Also when zero balanced is mentioned.. that is to Porsche specs... When you balance the assembly to better than Porsche specs..You need to match mark the crank/flywheel/pressure plate.
__________________
Don't feed the trolls. Don't quote the trolls  http://www.southshoreperformanceny.com '69 911 GT-5 '75 914 GT-3 and others |
||
|
03-03-2009, 05:09 PM
|
|
|
Registered
Join Date: Jul 2000
Location: So. Calif.
Posts: 19,910
|
"....You need to match mark the crank/flywheel/pressure plate...."
So as not to confuse: During an engine build, while the flywheel and pressure plate masses can be included when balancing the engine parts (crank, rods, pistons, pins, rings, crank pulley, etc.), for practical purposes, the flywheel and pressure plate (and even clutch disk) should also be balanced independently of the crank. These are so-called replacement parts. The engine shouldn't rely on these parts to achieve basic balance. Sherwood |
||
|
03-06-2009, 10:01 AM
|
|
