Go Back  Offshoreonly.com > Technical > General Q & A
rocker arm stud diflection >

rocker arm stud diflection

Notices

rocker arm stud diflection

Thread Tools
 
Old 04-18-2015 | 06:31 PM
  #1  
Tinkerer's Avatar
Thread Starter
Registered
20 Year Member
 
Joined: Jan 2002
Posts: 4,612
Likes: 7
From: ALTO, MI
Default rocker arm stud diflection

How much is normal? I am running good roller rockers with the 641 hyd roller cam. aftermarket oversize push rods with ARP studs.
I am running the stock valve covers with the oil drippers removed and noticed a bump in the cover next to the oil fill hole. removed the cover and all of the rockers seam to be properly adjusted with out tearing into it. There is a rub mark on the bottom of the cover that shows that the lock nut is moving more than 1/4 inch. I find this hard to believe that it could flex that much without breaking. I have snapped cheaper studs on other motors in the past.
Tinkerer is offline  
Reply
Old 04-18-2015 | 06:41 PM
  #2  
Rookie's Avatar
Registered
20 Year Member
 
Joined: Jan 2003
Posts: 6,019
Likes: 1,521
From: Grand Rapids, MI
Default

Do you Have the rocker corner ground away? I believe #1 and #8 intake. I didn't grind mine enough and it was deflecting my valve cover a bit. Might not be your problem just throwing thoughts out there.

Last edited by Rookie; 04-18-2015 at 06:43 PM.
Rookie is offline  
Reply
Old 04-18-2015 | 06:44 PM
  #3  
Registered
15 Year Member
 
Joined: Oct 2007
Posts: 8,439
Likes: 93
From: yorkville,il
Default

i don,t think it could flex that far without breaking.
mike tkach is offline  
Reply
Old 04-18-2015 | 07:12 PM
  #4  
Tinkerer's Avatar
Thread Starter
Registered
20 Year Member
 
Joined: Jan 2002
Posts: 4,612
Likes: 7
From: ALTO, MI
Default

[ATTACH=CONFIG]540044[/ATTACH]


[ATTACH=CONFIG]540045[/ATTACH]
Attached Thumbnails rocker arm stud diflection-img_20150418_165312582.jpg   rocker arm stud diflection-img_20150418_165256708.jpg  
Tinkerer is offline  
Reply
Old 04-18-2015 | 07:13 PM
  #5  
Tinkerer's Avatar
Thread Starter
Registered
20 Year Member
 
Joined: Jan 2002
Posts: 4,612
Likes: 7
From: ALTO, MI
Default

These are not the rocker arms that you need to grind the corners.
You can see the mark on the underside of the cover.

There are marks from other nuts on the underside of the cover but none of them show this sign of movement.

This is the engine that has been in the Daytona for the last year. It runs perfect with NO strange noises.

Last edited by Tinkerer; 04-18-2015 at 07:16 PM.
Tinkerer is offline  
Reply
Old 04-18-2015 | 07:19 PM
  #6  
Registered
 
Joined: Apr 2004
Posts: 1,268
Likes: 239
From: Michigan
Default

Sounds like the stud may be loose in the head? If it moves 1/4 inch (which I think it would snap) you are diminishing lift/duration. check every one close.

Last edited by abones; 04-18-2015 at 07:24 PM. Reason: was typing during OP last post
abones is offline  
Reply
Old 04-18-2015 | 07:46 PM
  #7  
Rookie's Avatar
Registered
20 Year Member
 
Joined: Jan 2003
Posts: 6,019
Likes: 1,521
From: Grand Rapids, MI
Default

Do you think that at one time it did snap one off and that is the the prior damage? If you put the cover back on does it spot off on the nut? When my rockers were touching my covers I could hear a distinct hollow noise. Throwing ideas out.
Rookie is offline  
Reply
Old 04-18-2015 | 07:51 PM
  #8  
Tinkerer's Avatar
Thread Starter
Registered
20 Year Member
 
Joined: Jan 2002
Posts: 4,612
Likes: 7
From: ALTO, MI
Default

Before the motor goes back into the boat it WILL be checked out.
I am in the process of stripping the boat ao it can go to the gel coat repair guy to have everything fixed that the previous owner did. I am also adding an extension box so some of the holes on the transom need to be filled. AND I am raising said box 1 inch and going from a standard deck to a tall deck block that will raise and spread the exhaust ports. And reworking the dash.

[ATTACH=CONFIG]540046[/ATTACH]
[ATTACH=CONFIG]540047[/ATTACH]
Attached Thumbnails rocker arm stud diflection-img_20150418_154450912.jpg   rocker arm stud diflection-img_20150418_154910756_hdr.jpg  
Tinkerer is offline  
Reply
Old 04-18-2015 | 07:53 PM
  #9  
Tinkerer's Avatar
Thread Starter
Registered
20 Year Member
 
Joined: Jan 2002
Posts: 4,612
Likes: 7
From: ALTO, MI
Default

That rocker is on the base circle of the cam and nothing seems to be loose. I will check it out before it goes back into the boat.
The broken rocker arm stud was a few engines ago.
Tinkerer is offline  
Reply
Old 04-18-2015 | 08:07 PM
  #10  
Registered
10 Year Member
 
Joined: Jun 2012
Posts: 1,455
Likes: 1
From: OK CIty, OK
Default

Originally Posted by mike tkach
i don,t think it could flex that far without breaking.
Or permanent deflection.
Cole2534 is offline  
Reply


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.