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 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 09-15-2018, 08:56 PM   #4
Dead Parrot
Registered User
 
Join Date: Aug 2012
Location: Oklahoma City, OK
Posts: 2,495
Re: Need Help With Timing Curve (I have Numbers)

Vacuum advance is only a part throttle thing. Assuming a daily driver street setup, part throttle is a leaner mix at lower cylinder pressure due to the high vacuum which burns slower and needs to be lit earlier. As you put your foot into it, vacuum goes down, cylinder pressure rises, burn rate speeds up but vacuum advance is less now because of lower vacuum so the fire get lit later.

Adjust your mechanical first to be full in at 3000~3500 and then worry about vacuum advance if it pings at part throttle.

There are several articles on timing and the 50+ advance at part throttle is what you want, again assuming a relatively normal street engine.

There are also charts on the various AC vacuum pots available and when they come in and how much.
Dead Parrot is offline   Reply With Quote
 

Bookmarks

Tags
1974, 350, c10, timing


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 05:55 AM.


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