rocker options for cad 4.9 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


General GM Chat When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made. Chat about all things GM (and related cars). Off-topic stuff should be in the Lounge, and all Model specific mechanical problems should be posted in the proper forum.

Reply
 
 
 
Thread Tools Search this Thread
Old 08-18-2015, 12:00 AM   #1
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Dec 2014
Posts: 45
Thanks: 0
Thanked 0 Times in 0 Posts
ehall is on a distinguished road
Default rocker options for cad 4.9

Tried to post in performance but locked out. The Cadillac 4.9 has stamped steel rockers bolted to an aluminum support bar, with aluminum pivot/bridge holding each pair together. At high RPM the steel bolts rip out of the support bar holes (fixable with helicoils), and over time the rotational stress also causes the aluminum pivot to snap. Both are very common failures when the engine is pushed. I bought new supports and pivots when I swapped engines, and broke one of the new pivots a few weeks ago less than 5k miles later.





I am trying to come up with some options for stronger pivots. There is nothing aftermarket for these engines so I may need to adapt something, or change to a different style. 1.6:1 ratio not terribly uncommon

Sealed Power has these old rockers that look very similar except a 2-piece pivot and bridge, but the bridge is straight instead of off-set. If I could find/make off-set bridges maybe that would work



This 4.9 build in a Fiero used some pedestal mounted roller rockers, but he machined the support bar to keep them from twisting. Old thread and the OP sold the car to somebody else so can't ask about it.



I was looking at some roller rockers with a center bar and it looks like the box stand could be bolted into the support bar



Comp Cams has a few designs, same hurdles as the above, need to stop them from twisting somehow

Any ideas?
Attached Thumbnails
rocker options for cad 4.9-2015_rear_rockers.sized.jpg   rocker options for cad 4.9-2015_broken_rocker_guide.sized.jpg   rocker options for cad 4.9-_571_zpsuilurfw0.jpg   rocker options for cad 4.9-dcp01895_zps2wjsxrof.jpg   rocker options for cad 4.9-box_stand.jpg  

ehall is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
2001 cad 4.6 randy1962 Cadillac 1 09-16-2012 09:32 PM
Options for 2000SSEI; VIN lookup availability; Accessory Kit options Syn General GM Chat 2 04-07-2010 11:29 AM
Aftermarket rocker options 94 ssei? streetfreak 1992-1999 1 04-08-2009 08:02 AM
lookie what I made (CAD) corvettecrazy Lounge 16 02-20-2006 12:14 PM
Bonneville Drawing (CAD) Logan General GM Chat 25 12-20-2005 09:48 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 10:49 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.