Cam with P.J. gear drive. How to set up correct thrust??? - Team Camaro Tech
Engine General Engine Discussion.

 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old Feb 6th, 07, 11:39 AM Thread Starter
Senior Tech
 
Join Date: Nov 2006
Location: Bend, OR
Posts: 1,702
Cam with P.J. gear drive. How to set up correct thrust???

[SIZE=3]My bbc has a PJ gear drive in it. When I pulled the motor apart to do a cam change, I notices the cam was not centered on the rear bearing. It ever so slightly dug into the bearing to where you could see a lip starting. Granted, the cam I was changing had a good 50K + in miles on it. I used the thrust washer provided between the gear and the cam, and I used a cam button. What did I miss?????? Thanks!!!!

P.S. I looked thru the bore to see if the cam had been wearing on the rear soft plug and it had not!

Last edited by dubs68camaro; Feb 6th, 07 at 12:59 PM.
dubs68camaro is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old Feb 6th, 07, 07:38 PM
Senior Tech
george
 
Join Date: Sep 2006
Location: detroit
Posts: 2,291
Re: Cam with P.J. gear drive. How to set up correct thrust???

Quote:
Originally Posted by dubs68camaro View Post
[size=3]My bbc has a PJ gear drive in it. When I pulled the motor apart to do a cam change, I notices the cam was not centered on the rear bearing. It ever so slightly dug into the bearing to where you could see a lip starting. Granted, the cam I was changing had a good 50K + in miles on it. I used the thrust washer provided between the gear and the cam, and I used a cam button. What did I miss?????? Thanks!!!!

P.S. I looked thru the bore to see if the cam had been wearing on the rear soft plug and it had not!
Do you mean the thrust washer is working on the forward cam bearing????Not sure by your description but if you had .010 button clearance initially you may have a chain cover that flexes and allows the cam to walk forward and the thrust washer could drop off the backside of the cam driven gear.
fatblock is offline  
post #3 of 7 (permalink) Old Feb 6th, 07, 08:37 PM Thread Starter
Senior Tech
 
Join Date: Nov 2006
Location: Bend, OR
Posts: 1,702
Re: Cam with P.J. gear drive. How to set up correct thrust???

Quote:
Originally Posted by fatblock View Post
Do you mean the thrust washer is working on the forward cam bearing????Not sure by your description but if you had .010 button clearance initially you may have a chain cover that flexes and allows the cam to walk forward and the thrust washer could drop off the backside of the cam driven gear.
No.....it's the rear bearing.....back of the block. I'm wondering if the thrust washer is not thick enough to keep it more shimmed out??
dubs68camaro is offline  
 
post #4 of 7 (permalink) Old Feb 6th, 07, 08:57 PM
Senior Tech
george
 
Join Date: Sep 2006
Location: detroit
Posts: 2,291
Re: Cam with P.J. gear drive. How to set up correct thrust???

Quote:
Originally Posted by dubs68camaro View Post
No.....it's the rear bearing.....back of the block. I'm wondering if the thrust washer is not thick enough to keep it more shimmed out??
The thrust washer is not a shim.It protects your block from wear.The cam button helps locate the cam.If the cam walked, the thrust washer could drop down and hold the cam forward.PJ wants .010 between the roller bearing button on a cover with no flex.
fatblock is offline  
post #5 of 7 (permalink) Old Feb 7th, 07, 05:12 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,763
Garage
Re: Cam with P.J. gear drive. How to set up correct thrust???

Quote:
Originally Posted by fatblock View Post
The thrust washer is not a shim.It protects your block from wear.The cam button helps locate the cam.If the cam walked, the thrust washer could drop down and hold the cam forward.PJ wants .010 between the roller bearing button on a cover with no flex.
What also helps is a short water pump with a thick metal backing plate rather than the usual stamped plate.

The cam button needs a good support as the timing cover flexes also. And my PJ on my shelf has no roller bearing button, just two pieces, a male & female button fitting into the center bore of the camshaft. Would be nice if it was a roller button, maybe I'm missing something.

The cam would have to move out of the block by the width of the bearing journal for the thrust washer to fall down. I don't think this is possible.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
post #6 of 7 (permalink) Old Feb 7th, 07, 08:29 AM Thread Starter
Senior Tech
 
Join Date: Nov 2006
Location: Bend, OR
Posts: 1,702
Re: Cam with P.J. gear drive. How to set up correct thrust???

Quote:
Originally Posted by Everett#2390 View Post
What also helps is a short water pump with a thick metal backing plate rather than the usual stamped plate.

The cam button needs a good support as the timing cover flexes also. And my PJ on my shelf has no roller bearing button, just two pieces, a male & female button fitting into the center bore of the camshaft. Would be nice if it was a roller button, maybe I'm missing something.

The cam would have to move out of the block by the width of the bearing journal for the thrust washer to fall down. I don't think this is possible.
what's weird is that it's walking the other way.....the wear is on the FRONT of the rear bearing. It's like the cam is too far back. That's why I thought a thicker thrust to pull the cam up, but you are right, it rubs againts the block so the cam CAN'T come any farthur forward. Just thought of something.....who's to say the bearing was installed correctly to begin with?????? If it's installed too far forward, and the cam is where it's supposed to be, then the cam bearing would have a small portion that the correctly installed cam would not be touching.......thus the wear. Any one argee with my Hypothosis????
dubs68camaro is offline  
post #7 of 7 (permalink) Old Feb 7th, 07, 09:46 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,763
Garage
Re: Cam with P.J. gear drive. How to set up correct thrust???

By design, the direction of the gear cut of the distributor/camshaft relationship with the load of the oil pump, the camshaft is always trying to go out the back of the block.

The cam bearings in the block are usually flush with the webbing of the block. Better fitment test is to compare the hole alignment of the bearing shells and the block oil passage holes with a coat hangar, if the wire passes through and the visual check shows the all of the holes of each aligned, then one can assume the bearing shells are correctly installed.

The bearing journal of the camshaft may be wider than the bearing shell itself.

Give a man a rescued dog for the health of both their souls. May 2017 ROTM Winner - Thank you!
'
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
CUBS - 2016 World Series Champions - Thank you, Joe Madden enjoy your next chapter.
Everett#2390 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
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.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Drive Gear slipped inside norcalcamaro Transmission & Driveline 3 Feb 17th, 06 10:09 AM
speedo drive gear mjsmilford Transmission & Driveline 11 Dec 8th, 05 09:04 PM
New cam and timing gear set! supv26 Performance 1 Sep 22nd, 03 08:00 AM
274xe vs. hot cam on vortecs czar Performance 20 Jul 16th, 02 12:01 PM
aluminum water pump and cam thrust bolt big gear head Performance 12 Feb 9th, 02 04:04 AM

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

 
For the best viewing experience please update your browser to Google Chrome