Team Chevelle banner

Timming - I'm lost

1636 Views 9 Replies 6 Participants Last post by  onovakind67
Ok guys i have been reading some old posts - trying to figure out how to correctly set my timming - and all i am getting is confused. I will try to post what i've gathered from it and maybe somebody can shed some light on this and correct my wrong ideas. 1st) You need to disconect the hose going from the vacuum advance pod on the dist.to the carb and block them off. 2nd) I have heard two different theorys on how to set the initial advance - one is off the timming tab and # two is to rotate the distributer. (which is it - or is it both) - like you use the tab to get it where you want it and then rotate the dist. to readjust -maybe to make it start easier and then rotate it again to bring it back to where you want it? 3rd) I know the mechanical advance is all in the weights and how fast it comes in is due to the springs but where does the vacuum advance come into play? It's got to be there for a reason. 4th) Total timing as stated by a tech archive is the initial plus the mechanical - i can understand that ( minus the fact that i still dont know where the vacuum advance comes in) but then it says that to adjust total timming (holding the engine at 3000 rpms to 3500 rpms - depending on when all the timing is in) to rotate the distibuter - this doesnt sound right to me and maybe i am misunderstanding it but wouldnt that make the initial timming lower or higher ? I want the initail to stay the same and the "total" to be correct and to do this i would have to change the weights right? Maybe i have answered my own question here but what i think it is that i need to know is how to check the timming - to make sure it is right. I know i will need to get a balancer tape and a timming light but how do i go about it. - Once i have my intial set where i want it do i - just play with the weights until they are where i want them or do i just rotate the dist.? Thanks for letting me aimlessly ramble and for any replies that come from it.

Dan
See less See more
Status
Not open for further replies.
1 - 3 of 10 Posts
Ok guys thanks for clearing everything up for me! I hope you dont mind me asking more questions because i have a couple of more. These relate to the performance of the engine through timming now rather that how to set it. 1) As the duration of the cam increases so should the amount of initial timming - correct? So with a stock cam is 10 degrees going to be too much? How do i know what the engine likes best. Also when i go to a bigger cam this spring how much do i need to add? Is there any equations and what factors play into this? Also since the vacuum advance is used during light loads can i use this as a way to offset extra timming - much the same as a wider lobe seperation on a cam makes it idle smoother. How do you get the best performance out of the timming without going into denotation? How much total advance should i run? and when should it all be in (3000 rpms vs. 3500 rpms) I can provide my specs if needed. Thanks again for all your help I really appreciate it!

Dan
onovakind67 thanks for the reply and the link. I now have the Dave Andrews article in my personal bookmark and have found it to be very helpfull. I appreciate everyones help!
Hey while im at it I have another question for you. On a chevy Hei, isnt the limit of the weight travel determined by the center plate/weight, that the actual rotating weights rotate around? thanks again

Dan


[This message has been edited by 68chevelle (edited 04-24-2001).]
1 - 3 of 10 Posts
Status
Not open for further replies.
Top