Timing a SBC - 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 05-08-2010, 05:31 AM
Registered User
 
Join Date: May 2010
Location: East Of OZZ
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Timing a SBC

OK earlier on I asked about the makes on a timing Chain. Lining up the dots ect... I ended up taking the front timing chain cover off to make sure dot to dot was correct. It was. I was told that both dots should be at the 12:00 for the installation of the distrib. That would be TDC on the compression stroke. It was just that when I checked it. After checking all this I had done my homework correct it had seemed. I still get burping and some fire out of the carb. I've tried moving the advance around both ways and it still acts like the timing is wrong. I have never dropped a distib. in without a smooth fire up as I am very anal about double checking. That doesn't mean I didn't but everything checks out. I still have one hair left and open to anything at this point. Should I go against everything I know and put the distr. in 180 out? I am dumbfounded and listening...
Thanks Cat

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-08-2010, 05:56 AM
Registered User
 
Join Date: Dec 2009
Location: holland ohio
Age: 49
Posts: 67
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Did you verrify that number one cylinder was at top dead center, and your rotor pointing at number one terminal on your cap. You could be on number 6 without verify this? Also I had a cheap timing chain once that was 6 degrees off. Make sure you find top dead center with your timing tab, some tabs need to be adjusted to the balancer. Sounds like your timing is retarted. Also verify correct order of plug wires on cap.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-08-2010, 08:51 AM
Registered User
 
Join Date: Mar 2010
Location: Seattle
Age: 55
Posts: 3
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
If its burping and sending fire out the carb it sure sounds like 180 out.

Just to be clear, TDC with both valves closed - right? Rotor pointing just a tad before #1, clockwise rotor rotation with firing order 1 8 4 3 6 5 7 2.

If your absolutely positive about all above you've got some other problem but I'd move the dist. 180 first jsut to be sure.....

Just my .02
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-08-2010, 08:51 AM
avmechanic's Avatar
Gearhead
 
Last photo:
Join Date: May 2010
Location: Langley B.C. Canada
Age: 42
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I believe you are 180 out by your explanation. The two dots on the timing gears must be next to each other. 12:00 for the crank and 6:00 for the cam gear. You need to be TDC #1 cyl. compression stroke. You can check by pulling the plug and sticking your finger in the hole slightly to feel the air push out as number 1 comes up on it's compression stroke while turning the engine. Then stab your distributor in with the rotor pointing to #1 plug wire. Good luck with it.
Greg
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 05-08-2010, 09:03 AM
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 597 Times in 546 Posts
If the cam phasing is correct (the lining up of the dots) and the distributor is installed correctly and the plug wires are correct, I would strongly suspect the valves to not be adjusted correctly- as in too tight, causing them to not seat fully. This will cause the problems you describe.

A quick test for this, is to run a compression test on the engine:

Remove all the plugs, disable the ignition and prop the throttle WFO.

Test each cylinder and record the results. "Pump" each cylinder the same number of times. I always position the gage so I can see it as I crank the engine- I give it three "jumps" of the gage, per cylinder (the gage jumps each time the piston comes up on TDC firing).

If you come to a cylinder that does not show good compression, stop there, pull the valve cover for that bank and check that cylinder's valve adjustment.

If you have any question regarding whether the tab and damper are correctly showing TDC, use DETERMINE TDC.

If you do not have a degreed damper or a dial back timing light, you can MAKE A TIMING TAPE. Use the temporary tape to set total timing, etc. and for marking the damper w/the total for future reference.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-08-2010, 09:07 AM
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 597 Times in 546 Posts
Quote:
Originally Posted by avmechanic
I believe you are 180 out by your explanation. The two dots on the timing gears must be next to each other. 12:00 for the crank and 6:00 for the cam gear.
For the record- in this position (timing gear dots closest to each other), #6 will be TDC firing. #1 will be TDC exhausting.

Rotating the crank one revolution will put the cam gear's dot @ 12 0'clock and then #1 will be TDC firing, #6 will be TDC exhausting.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 05-08-2010, 09:17 AM
avmechanic's Avatar
Gearhead
 
Last photo:
Join Date: May 2010
Location: Langley B.C. Canada
Age: 42
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by cobalt327
For the record- in this position (timing gear dots closest to each other), #6 will be TDC firing. #1 will be TDC exhausting.

Rotating the crank one revolution will put the cam gear's dot @ 12 0'clock and then #1 will be TDC firing, #6 will be TDC exhausting.
What?? Since when??? The Dots face each other on assembly which is TDC #1. Here is a youtube video for reference. http://www.youtube.com/watch?v=Zr_n0cL46NM
Greg
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 05-08-2010, 09:54 AM
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 597 Times in 546 Posts
Quote:
Originally Posted by avmechanic
What?? Since when??? The Dots face each other on assembly which is TDC #1. Here is a youtube video for reference. http://www.youtube.com/watch?v=Zr_n0cL46NM
Greg
On a SBC, if you take an engine that is running, pull the timing set out and reinstall a timing set the #6 hole will be at TDC firing w/the dots closest to each other.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 05-08-2010, 10:11 AM
avmechanic's Avatar
Gearhead
 
Last photo:
Join Date: May 2010
Location: Langley B.C. Canada
Age: 42
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by cobalt327
On a SBC, if you take an engine that is running, pull the timing set out and reinstall a timing set the #6 hole will be at TDC firing w/the dots closest to each other.
Well that is interesting. I guess I will take your word for it. I have never looked at the timing chain again after initial assembly, I just look for #1 TDC with the plug out method, and work form there.
Greg
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 05-08-2010, 10:38 AM
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 597 Times in 546 Posts
Quote:
Originally Posted by avmechanic
Well that is interesting. I guess I will take your word for it. I have never looked at the timing chain again after initial assembly, I just look for #1 TDC with the plug out method, and work form there.
Greg
Now, this has always been the case w/the timing sets I've worked with- Cloyes mainly.

There could be sets that have #1 at TDC firing when the dots are aligned, I don't know, except that I've never seen one that aligns #1 TDC firing- yet! lol
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 05-08-2010, 01:34 PM
Registered User
 
Last photo:
Join Date: Apr 2010
Location: Hawaii
Posts: 373
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
You're 180-off. Pull the dist. and spin the rotor 180 and drop it back in (the oil pump shaft will line up). I've seen enough timing sets that make you think you're zero'd...but you're 180-off.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 05-09-2010, 07:45 AM
cwmoss's Avatar
Registered User
 
Join Date: Feb 2010
Location: Texas
Age: 62
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
You are 180* out. They say put the dots together to make installing the chain and cam gear simple. I found this out the hard way. When I built my first engine, I put the dots together (cam dot was at 6 and the crank dot was at 12), and got the same results as you are having. I pulled that car round and nothing. I took it to a friend who was a mechanic. He got it going. I was 180* out. The dots should both be at the 12 o'clock position, that will put #1 at TDC. The dist. shoud the be dropped in with the rotor pointing at the #1 wire. This works every time it's tried.
A good way to prove this is have the intake off and put both dots at each other (crank at 12 and cam at 6). Check the pushrods on #1. You will be able to turn the intake, because it is closed, but the exhaust will be open. Now check #6, you will be able to turn both, because they are both closed, it's at TDC.
Don't feel bad, most everyone has done this.
Daryl (cwmoss)
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 05-09-2010, 08:25 AM
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 597 Times in 546 Posts
Quote:
Originally Posted by cwmoss
A good way to prove this is have the intake off and put both dots at each other (crank at 12 and cam at 6). Check the pushrods on #1. You will be able to turn the intake, because it is closed, but the exhaust will be open. Now check #6, you will be able to turn both, because they are both closed, it's at TDC.
Don't feel bad, most everyone has done this.
Daryl (cwmoss)
CW Moss- wasn't he the wheel man in Bonny and Clyde?
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 05-09-2010, 09:10 AM
cwmoss's Avatar
Registered User
 
Join Date: Feb 2010
Location: Texas
Age: 62
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
You got it. The movie came out when I was in high school. One of my buddies started calling me c.w.moss, because I was the only one in our lttle group that had a car, a 54 Merc Monteray(??). My parents bought it new in 54. It was a 2 door Hardtop, with an overdrive 3 speed. My dad was a Merc man. I was the wheel manfor our group. It has stuck all of these years.
Thanks for asking,
Daryl (cwmoss)
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
Does anyone make a 12:00 timing tab for SBC TNshadetree Engine 7 02-04-2010 09:44 PM
Chevy SBC, finding TDC without timing marks 04SilveradoMykk Engine 2 10-25-2009 06:11 PM
SBC 355 Timing Question Fasazu Engine 7 10-16-2009 08:59 PM
SBC Ignition Timing snod83 Engine 1 04-19-2004 04:42 PM
SBC ignition timing advice please Limey Simon Engine 5 07-01-2003 07:42 AM


All times are GMT -6. The time now is 08:56 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.