|
Rocker Stud Wear
2 Attachment(s)
Could someone tell me if the wear marks on this rocker arm stud are unusual? If so, what is the likely problem? Could it be a too narrow rocker slot width? Motor is a 351W stroked to 418, Comp Cams roller with .576 valve lift, Comp Pro-Magnum rockers. Thanks.
Attachment 12742 Attachment 12743 |
Well, I could be out to lunch on this, but it looks like you don't have enough clearance for the lift you are pushing with that cam.
|
You have exceeded the allowed space between the fulcrum point and the push rod cup. Or the roller to the fulcrum point.
I used to see them after the fact. Broken, the pushrod sticking through the top of the valve cover. A connecting rod out the side of the block. You are lucky you decided to pull them. :D :D |
Thanks for the replies. Do I understand then, that longer rocker studs should fix this? If longer studs aren't available, is there another simple fix? Also, how can I determine what the allowed space between the fulcrum point and the push rod cup actually is, so that I know how tall the studs need to be? I'd prefer to avoid trial and error if possible.
Thanks again. |
The wear marks are not unusual
Jerry |
Problem Solved
Just to close this out, the wear marks were caused by excessive clearance between the rocker stud and the hole in the rocker arm trunnion. This, in turn, was caused by the trunnion holes being too large. The holes should have been .438" in diameter, but were .003-.006" larger than that. This has been confirmed by Comp Cams (rockers are their Pro-Magnums), and they are rebuilding the rockers with new trunnions under the warranty. Their warranty guy said he had never seen this problem before.
Although I didn't say this in the original post (because I hadn't at that time examined all the worn studs), some of the wear was severe enough that you could easily feel a ridge on the stud with your finger. The rockers were really digging into the studs. Thanks for the responses above. |
| All times are GMT -7. The time now is 09:32 PM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: