Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 Engine Rebuilding Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Dec 2013
Location: Los Angeles
Posts: 64
911sc oem 10mm rod bolts and nuts question

Hi Everyone
I need help and advice, Iím starting to rebuild my 911sc engine but I think I made the first mistake
I got new OEM style rod bolts and nuts and I torqued them according to Wayneís book 20Nm and 90 degrees, now I realized that this is probably not the correct method for these oem rod bolts and nuts
What should I do now? Leave as is, disassembly the rods and get new oem bolts & nuts and torque them to 50-55Nm only, or a new ARP rod set ?
Anyone had this issue before?
Thanks
Jose
Old 05-31-2018, 07:15 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Member 911 Anonymous
 
DRACO A5OG's Avatar
 
Join Date: Sep 2007
Location: Rancho Palos Verdes
Posts: 14,119
Garage
Send a message via Skype™ to DRACO A5OG
Why take a risk. Remove and go with ARPs then check for proper stretch specs.
__________________
'85 Carrera Targa
Factory Marble Grey/Black * Turbo Tail * 930 Steering Wheel* Sport Seats * 17" Fuchs (r) * 3.4 * 964 Cams * 915 * LSD * Factory SS * Turbo Tie Rods * Bilsteins * Euro Pre-Muff * SW Chip on 4K DME * NGK * Sienes GSK * Targa Body Brace
PCA/POC
Old 05-31-2018, 07:31 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Join Date: May 2007
Location: Santa Cruz, CA
Posts: 21
I agree that ARPs are the way to go. I was told that the rod ends need to be redone with the ARP bolts because they are torqued to a higher number so I had the local Porsche machine shop do that job. I can be sure this is absolutely necessary but I did it to be sure. Use a stretch gauge to ensure preload.
Old 05-31-2018, 10:14 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Jul 2013
Location: Brisbane, Australia.
Posts: 505
Conrod Bolt "re-use" question
Old 06-01-2018, 12:27 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Dec 2013
Location: Los Angeles
Posts: 64
What is the correct torque process for these OEM 10mm connecting rods bolts ?
Old 06-01-2018, 07:49 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: May 2004
Posts: 130
The factory spec for the 10.00mm x 1.25 bolt is 20NM and 1 x 90 degree.

There is nothing wrong with the factory bolt if its used in the application it was designed for. Proper installation is always required.


Every time bolts are exchanged the rod BE has to be measured. If the BE size is out of spec, then the new bolt will be stretched a minimum of 3 times. Its good practice and I would suggest that all the bolts are identified and their free length measured before installation. Then their stretched length can be measured, but more importantly as in the case, after any tightening, the bolts initial free length can be compared. As long as the bolt returns to its free length, it can be reused.

Hope this helps.

Discard any bolt that does not return to its free length.
Old 06-01-2018, 04:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
Registered User
 
Join Date: May 2004
Posts: 130
Maybe I should explain the 3 times the bolt gets stretched.

1st. Installation and measure the BE size.
2nd. Fit bearings after rebuilding to measure bearing ID.
3rd. Fit rods to crankshaft.
Old 06-01-2018, 04:10 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Nov 2007
Posts: 11
Sounds like you have the updated “12.9” steel bolts. Tighten your bolts another 90 degrees, and call it done.

- Jeff

__________________
-1978 911 SC
-2002 996 Turbo
-2015 WRX STi

Last edited by jbahrami; 06-18-2018 at 05:37 PM..
Old 06-18-2018, 05:30 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
KTL KTL is offline
Schleprock
 
KTL's Avatar
 
Join Date: Sep 2000
Location: Frankfort IL USA
Posts: 15,598
Send a message via Yahoo to KTL
Gotta be careful here to be sure we're all talking about the same bolts. The SC bolts are M10 x 1.25 and they have a different torque spec than the M9 x 1.25 bolts used in the 930 3.3L and the 3.2L Carrera bolts (this includes the 964 3.6 bolts as well since they also are the exact same connecting rod). The complete TSB posted by Jeff is this





Unfortunately the handy little spec book for the Carrera and 930 (I have one for '84 to '87 911/930 models) has a error stating the connecting rod bolts are M10 x 1.25 when they are actually M9 x 1.25



The original specification for the earlier conrods using M10 bolts is actually just 50Nm, according to the old '72-'83 workshop manual. There's nothing detailed with a step by step procedure. There's just a listing for the connecting rod nuts that says 50Nm!



The most recent 930 workshop manual also has an error and lists the 3.0 Turbo ('75-'77) rod bolts as M9 x 1.25 (they are for certain M10 x 1.25 because they have the same 914.103.171.01 part number as the 3.0 SC and 2.7L rod bolts) but does also say 50Nm



If we're talking ARP bolts, the specs are also different for the M9 and M10 bolts



__________________
Kevin L
Present: '86 Carrera, '79 911SC widebody conversion rolling racecar shell
Past: '87 Carrera
Old 06-20-2018, 10:34 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Puny Bird
 
Mark Henry's Avatar
 
Join Date: Nov 2002
Location: Port Hope (near Toronto) On, Canada
Posts: 3,865
Just an FYI
So far I've used ARP rod bolts on type 1 and 4 VW and 9mm, 10mm and 996 Porsche and the stretch was always the same as the ARP recommended torque, using the ARP grease.
__________________
'74 Porsche 914, 3.0/6
'67 Bug, 2600cc T4
'67 Bus, 2.0 T1
Not putting miles on your car is like not having sex with your girlfriend, so she'll be more desirable to her next boyfriend.
Old 06-21-2018, 06:02 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 11:04 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.