cam degreeing - 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 03-14-2004, 04:29 AM
New Member
 
Join Date: Nov 2003
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
cam degreeing

What is the easiest way to degree a cam in,also what is total timing?
Thanks for any replies,
Rick

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-14-2004, 06:37 AM
HJCHEVY400's Avatar
When Cool Meant Cubic Inches
 
Last photo:
Join Date: Jan 2004
Location: Adelaide, Australia
Age: 34
Posts: 47
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Go to this site, at crane cams, and download the pdf file for viewing. This will tell you what you need to know.
When reading, they'll refer to a piston stop. Make one from a gutted spark plug and a bolt with it's end filed down, so as to not damage the piston.

http://www.cranecams.com/pdf/803.pdf

Best wishes

Initial timing is the degrees of timing at idle.

Total timing is the initial plus the timing advance made by the vacuum advance or centrifugal advance, whichever is present on your distributor.

eg., intial timing @ idle = 10 deg.,

total timing @ 3000rpm (once vacuum advance or centrifugal advance cut in) = 35 deg.

Initial timing is the degrees of timing at idle.

Total timing is the initial plus the timing advance made by the vacuum advance or centrifugal advance, whichever is present on your distributor.

eg., intial timing @ idle = 10 deg.,

total timing @ 3000rpm (once vacuum advance or centrifugal advance cut in) = 35 deg.

Last edited by HJCHEVY400; 03-14-2004 at 06:33 AM.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-16-2004, 02:02 PM
New Member
 
Join Date: Nov 2003
Posts: 27
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
timing

Thanks for the info know I understand what true timing is.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-16-2004, 06:22 PM
TravisT's Avatar
Member
 
Last photo:
Join Date: Feb 2004
Location: Warner Robins, GA
Age: 33
Posts: 76
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Sorry for jumping on this thread, but it seems to be a good place to ask this.

I know the basics about timing, but I'm having some problems timing my buick 3.8L engine. I did a search and found someone who said that you should set the initial timing to achieve the greatest vaccuum, and then back off about a pound or so. I tried this and my initial timing was WAY retarded (my pointer goes from 0 thru about 20 BTDC, and it was over 20. Engine rpms went up while going further BTDC, and vaccuum maxed out at about 20 in/m. It may actually pull higher vaccuum, but without removing the distributor, I couldn't turn it any more.)

Also, should the vaccuum advance be connected to the ported vaccuum port, or the full time vaccuum port?

The engine has just been rebuilt, and while it runs decent, but I think I still have some tuning to do. It is bored .060 and has an edelbrock 500cfm carb kit (intake/carb/cam). I am using the edelbrock timing set and running the cam strait up. Not exactly sure what the compression is, (probably about 10:1 give or take a little) but I replaced the stock dished pistons with flat tops. If I left out any important info, let me know.

TravisT
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-16-2004, 10:41 PM
Silver_Camaro's Avatar
Superior Wheels Quality Tech
 
Last photo:
Join Date: Jun 2003
Location: Kansas
Age: 28
Posts: 385
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally posted by TravisT
Sorry for jumping on this thread, but it seems to be a good place to ask this.

I know the basics about timing, but I'm having some problems timing my buick 3.8L engine. I did a search and found someone who said that you should set the initial timing to achieve the greatest vaccuum, and then back off about a pound or so. I tried this and my initial timing was WAY retarded (my pointer goes from 0 thru about 20 BTDC, and it was over 20. Engine rpms went up while going further BTDC, and vaccuum maxed out at about 20 in/m. It may actually pull higher vaccuum, but without removing the distributor, I couldn't turn it any more.)

Also, should the vaccuum advance be connected to the ported vaccuum port, or the full time vaccuum port?

The engine has just been rebuilt, and while it runs decent, but I think I still have some tuning to do. It is bored .060 and has an edelbrock 500cfm carb kit (intake/carb/cam). I am using the edelbrock timing set and running the cam strait up. Not exactly sure what the compression is, (probably about 10:1 give or take a little) but I replaced the stock dished pistons with flat tops. If I left out any important info, let me know.

TravisT
I may be wrong, but it sounds like you may be one plug off on the distributor... I'd say put the #1 piston at TDC and pull the distributor cap.. And see if the rotor is pointing to the #1 spark plug.

And vacuum advance goes on ported vacuum.. So that there is little to no advance at idle.. But gradually advances as rpms increase.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-17-2004, 05:27 AM
TravisT's Avatar
Member
 
Last photo:
Join Date: Feb 2004
Location: Warner Robins, GA
Age: 33
Posts: 76
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Well I may be wrong, but if I was one plug off wouldn't the timing be advanced and not retarded (of course it would depend on which way I was off). I can get the timing to 8 BTDC and it runs ok, but from what I heard about timing according to your vaccuum reading, you are supposed to tune to the highest vaccuum which reading is over 20 BTDC with no vaccuum advance.

I thought the advance went on the ported side, thanks for clarifying that for me.

If someone can verify the timing method using the vaccuum guage, I would greatly appreciate it!

TravisT
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-19-2004, 01:43 AM
Silver_Camaro's Avatar
Superior Wheels Quality Tech
 
Last photo:
Join Date: Jun 2003
Location: Kansas
Age: 28
Posts: 385
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Doin it that way I've always heard to go with the greatest minifold vacuum then just barely back off..

Also way over 20 BTDC would be way advanced.. Not way retarded. Unless i'm thinkin backwards tonight.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-19-2004, 05:00 AM
TravisT's Avatar
Member
 
Last photo:
Join Date: Feb 2004
Location: Warner Robins, GA
Age: 33
Posts: 76
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
That would make sense now wouldn't it..... I guess it was late when I posted.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-20-2004, 03:05 AM
Silver_Camaro's Avatar
Superior Wheels Quality Tech
 
Last photo:
Join Date: Jun 2003
Location: Kansas
Age: 28
Posts: 385
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Yeah I recently set mine to 8 BTDC with the vac advance off and everything.. But there I was only pullin like 12 psi of vacuum... Didn't seem to have hardly any power.. So I hooked the vacuum guage up to it today and set it according to the manifold vacuum.. I"m probably runnin about 20 BTDC now and pullin 17 - 18 psi of vacuum throughout the rpm range now and it runs a heck of a lot better. Didn't have gas to take it on the highway and see how topend power is though. Just took it on the road in front of my house and roasted the tires all the way through first and let off there. Not bad for a 305 I suppose. hehe
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-20-2004, 07:32 PM
tweaked's Avatar
Member
 
Join Date: Mar 2004
Location: IN
Age: 40
Posts: 88
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
timing

I have the same timing problem, but I think I'm going to try a curve kit for better timing. I also have about 20btdc inital in order to get 36 at 2800-3000 rpm. When I do plug my vac. advance in I get another 16 deg. which brings me to 52 deg. at cruise. I haven't figured it out yet.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 03-20-2004, 11:49 PM
Magikal's Avatar
How can it go faster?
 

Last journal entry: Been a long Winter
Last photo:
Join Date: Jan 2004
Location: North Idaho
Age: 37
Posts: 240
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
For info on the vacuum timing adjustment, see thread

http://hotrodders.com/showthread.php?s=&threadid=35947

Basically, advance the distributor to find the highest amount of vacuum. Then you want to retard the timing 10% of the total vacuum.

For example: If the highest vacuum achieved is 20 then retard the distributor 2.0 to 18....If the highest vacuum is 16 then retard it 1.6 to 14.4....

Easy as that, the key being to back it off 10% of the maximum. Good luck
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



All times are GMT -6. The time now is 12:28 AM.


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.