Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - 1977 Chevy K20: Engine Suffers from Hesitation/Power Loss When In Drive
View Single Post
  #100 (permalink)  
Old 03-08-2012, 08:31 PM
barry425's Avatar
barry425 barry425 is offline
Registered User
 

Last journal entry: Barry's Vega
Last photo:
Join Date: Oct 2008
Location: Diamond Bar, California
Posts: 37
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
timing

Generally speaking,
Initial timing=8 degrees
Mechanical advance in distributor=26 degrees (at the crank)
Subtotal=34 degrees
Vacuum=14-16 degrees
Total= 8+26+14=48
This may be a little high for todays gas. I would limit total around 45 degrees.
Here is a method for finding the optimum timing settings. It is best if done on a hot day.

INITIAL:
Disconnect the vacuum advance hose and plug it.
Set the initial timing at 8 degrees.
Take off from a dead stop and see if the engine pings right off idle. If it does, then back off the initial timing until it stops.

MECHANICAL:
Make sure that the mechanical advance is correct with the timing light. Then take the warmed up engine out on the road and floor it.
If it is an automatic and it pings just after it shifts into a higher gear, back off the mechanical timing (you may have to buy a spring and weight kit).
If it is a stick, put it in a high gear (like 3rd) and floor it. If it pings, reduce the mechanical advance in the distributor (again, you may need a kit).

VACUUM:
If it doesn't ping, then put the vacuum line back on and drive it up a long hill. If it pings, get an adjustable vacuum pot and back off the total available vacuum timing by the screw/cam adjustment on the inside of the distributor (NOT the screw inside the vacuum nipple).

Continue the above steps until you get it to never ping and you're set.
Reply With Quote