Cam lobes grinding down!?!? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-05-2009, 12:27 PM
Registered User
 
Join Date: Aug 2009
Location: Waterford, mi
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Cam lobes grinding down!?!?

Hey gang, i have an 86 Monte Carlo SS with a newly rebuilt and balanced 355 sbc, dome pistons, 10.5:1 cr, vortec heads, comp beehive springs, lunati voodoo (flat tappet hydaulic) 504/525" lift 233/241 duration @ .050" lift cam, edelbrock intake and carb, etc..
My question is, with this same setup in a different 355 i ground 6 lobes on the voodoo cam within an hour. Now with this 355 balanced short block i bought, metal shaving are squirting with the oil out of the pushrods and rockers keep losening. I ran royal purple break-in oil for start up, i had 40-60 psi oil pressure, it has 30 minutes of run time and i am clueless. The first time i broke the cam in for 15 min at 2400-2800 rpm, this time i stayed around 1000-1500. From what i have heard these springs are compatible with vortec heads and higher lift than i am running.. i have plenty piston the valve clearance. please any advise will help. thanks
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-05-2009, 12:31 PM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 28
Posts: 8,226
Wiki Edits: 0

Thanks: 12
Thanked 218 Times in 203 Posts
you used a really agressive cam and no oil additive... basically you wiped out one cam, and then continued to wipe out another. If you don't know how to maintain an agressive cam like that I suggest buying one of the "older" less agressive types and they are far more durable and are more forgiving.

VooDoo's are great IF you have everything down to the gnat's arse- sounds like you need something less agressive.

I hope your bearings aren't trashed...
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-05-2009, 12:45 PM
Member
 
Last photo:
Join Date: Aug 2005
Location: Virginia
Posts: 875
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
did you put break in lube on either of them?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-05-2009, 12:52 PM
Registered User
 
Join Date: Aug 2009
Location: Waterford, mi
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I put the supplied camshaft assembly lube generously on the cam, and i used royal purple break in oil of the cam break in, which has all the additives like zinc and stuff. im thinking the spring pressure may be the problem but idk
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-05-2009, 12:56 PM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 28
Posts: 8,226
Wiki Edits: 0

Thanks: 12
Thanked 218 Times in 203 Posts
If the springs were bought seperately you're probably right- those cams are REALLY picky. I won't touch them anymore, they're nice when they work, but they're a PITA to get to work.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-05-2009, 12:59 PM
Member
 
Last photo:
Join Date: Aug 2005
Location: Virginia
Posts: 875
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
do you know how to adjust valves?
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-05-2009, 01:25 PM
Registered User
 
Join Date: Aug 2009
Location: Waterford, mi
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
yes, i adjusted on the stand to zero lash @ tdc plus 3/4 turn. then i was setting hot lash because they were clacking, that's when i noticed metal sparkles out of one of the push rods. i really cant imagine what would be doing this, does anybody know of any problems with beehive springs on vortec heads?
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-05-2009, 01:41 PM
OLNOLAN's Avatar
Registered User
 
Last photo:
Join Date: Apr 2009
Posts: 1,002
Wiki Edits: 0

Thanks: 209
Thanked 62 Times in 52 Posts
chewed camshaft

Hey bud, sorry you're having bad luck(I've been down that road before).Check out my recent thread in the engine section titled "Shell Rotella T". A fine fellow called "Huneycutt" posted a link to a video he created on proper camshaft breakin. Maybe it'll help you.olnolan
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-05-2009, 03:16 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 595 Times in 545 Posts
Quote:
Originally Posted by chevycarlo91
From what i have heard these springs are compatible with vortec heads and higher lift than i am running.
There were articles written that said certain retainers intended for the Gen III engines were OK to use on Vortec heads, etc.

These articles were misleading and/or outright wrong. There are Comp retainers for Vortec heads using beehive springs, and there are retainers for Gen III heads using beehive springs. The problem is (in the case I'm citing) the retainers, not the springs.

The image shows the difference in installed height between the two retainers- the springs are identical.


#787-LEFT, for Vortec/non- GEN III heads; #774-RIGHT for Gen III heads
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 08-05-2009, 03:30 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,192
Wiki Edits: 326

Thanks: 590
Thanked 755 Times in 645 Posts
See post #6 here....
Cam shaft break in
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-05-2009, 05:18 PM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,427
Wiki Edits: 0

Thanks: 3
Thanked 327 Times in 284 Posts
Quote:
Originally Posted by chevycarlo91
Hey gang, i have an 86 Monte Carlo SS with a newly rebuilt and balanced 355 sbc, dome pistons, 10.5:1 cr, vortec heads, comp beehive springs, lunati voodoo (flat tappet hydaulic) 504/525" lift 233/241 duration @ .050" lift cam, edelbrock intake and carb, etc..
My question is, with this same setup in a different 355 i ground 6 lobes on the voodoo cam within an hour. Now with this 355 balanced short block i bought, metal shaving are squirting with the oil out of the pushrods and rockers keep losening. I ran royal purple break-in oil for start up, i had 40-60 psi oil pressure, it has 30 minutes of run time and i am clueless. The first time i broke the cam in for 15 min at 2400-2800 rpm, this time i stayed around 1000-1500. From what i have heard these springs are compatible with vortec heads and higher lift than i am running.. i have plenty piston the valve clearance. please any advise will help. thanks
These new high intensity cams are real touchy to break-in lube, break-in spring pressure and spring compatibility and even getting these things right might not be enough. Mechanically these super fast cams are right on the edge of the material strength, the slightest thing goes wrong and the cam is powder in the oiling system.

To start with the cam must use the manufacturer's recommended spring. There's a lot more to a spring than ultimate pressure. Springs have harmonic responses to the rate of lift, amount of lift, and frequency of lift (RPM) and the inertial weights they are trying to control. The frequency as established by engine RPMs, the inertial response established by RPM on component weights including the spring's weight both as an object and as separate coils result in different springs that may have otherwise identical pressures at closed or open positions to have unique responses to the applied forces. A mismatch of forces and speeds can cause the spring to go into harmonic surges and oscillations that hammer the daylights out of the connected components. Naturally should this occur the weakest link in the chain of parts will fail. These days it's usually the lifter/lobe interface on flat tappet cams.

So stay with matched parts, the manufacturer has done the tests and knows the response of their products, when you start cross pollinating valve train parts, you're really on your own. Some may work together many do not.

Bogie
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-05-2009, 06:01 PM
Registered User
 
Join Date: Aug 2009
Location: Waterford, mi
Posts: 14
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks for the help guys, i'm convinced it is somehow related to the spring pressure. i guess i will clean it up and try a new cam/lifters and springs. I really hope to get her running by the dream cruise.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wich cam would you choose between these two? sbc 350 eric32 Engine 11 06-22-2009 05:57 PM
Cam shaft break in pena0724 Engine 23 04-09-2009 08:13 PM
383 chevy cam clearance john williams Engine 2 09-02-2007 07:12 PM
Cam break-in and zinc Frisco Engine 34 03-13-2007 08:22 PM
Cam Help black66 Engine 3 05-12-2003 06:15 PM


All times are GMT -6. The time now is 11:13 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.