The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 12-26-2017, 01:50 AM   #1
dmjlambert
Senior Member
 
dmjlambert's Avatar
 
Join Date: Apr 2016
Location: Cypress, TX
Posts: 3,860
Questions about using a timing light

Hi, I have a question about a timing light, please. I bought the fancier of the two Bosch lights offered at O'Reilly. I am not trying to set the timing right now, just observe what my timing is set to, and learn some. I have a 1969 CST/10 with 350 engine and quadrajet, and it has an HEI distributor from a later model year. My vacuum advance is connected to a manifold vacuum port on the carburetor (has vacuum at idle) during my observations.

I connected the timing light and it is set it for 4 cycle by default when turned on. I start the engine.

I point the light to the timing marks and pressed advance up button on the light until the mark on the balancer aligned with the 0 mark on the timing tag. The timing light reads 30.0. Then I continue to adjust the advance up button until the mark on the balancer lines up 5 marks to the right near the R. The timing light new reads 40.0.

Does each mark on the timing tag represent 1 degree? I do not have the type of timing tag with notches, the edge is flat as shown in the picture.

When I set the timing light to 2 cycle, the reading is 15.0 when the mark on the balancer aligned with the 0 mark on the timing tag, and the reading is 20.0 when lines up with 5 marks to the right near the R. So I am thinking 2 cycle setting is the appropriate one to use with this timing light and this engine, and I have 15 degrees total advance at idle. Do I understand this correctly?
Attached Images
     
dmjlambert is offline   Reply With Quote
 

Bookmarks

Tags
advance, timing, timing light


Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -4. The time now is 08:56 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com