C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Big Block Timing?

Old Jan 25, 2012 | 12:43 AM
  #1  
goyamaha's Avatar
goyamaha
Thread Starter
Cruising
 
Joined: Dec 2011
Posts: 14
Likes: 0
Default Big Block Timing?

Finally dropped in my rebuilt big block in my 68 Coupe and got her to fire once fuel made it to the carb. I had to retard the timing just a little from an eyeball adjustment where I had basically set the dist as close to dead on #1 as possible. I am just wondering how to adjust the timing now. Is there a typical setting that works well? I have a timing light and know how to use it but I just don't know where to set the timing.

Engine info:

1970 402 / .30 over (yes 402...it's a long story)
10.5:1
612/612 hydraulic roller cam with full roller rockers
Edelbrock Torquer II intake with a Holley 750 - Vac Secondary
Stock distributor with Accel electronic points eliminator kit (no vacuum advance)
Muncie M20
Stock timing gears

Thanks!
Reply
Old Jan 25, 2012 | 01:27 AM
  #2  
Les's Avatar
Les
Race Director
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 1999
Posts: 11,096
Likes: 990
From: Sierra Foothills CA
Default

Most big blocks like around 34 degrees total, give or take 1-2 degrees. I'm also running w/o vacuum advance because with my cam I couldn't find the sweet spot until I eliminated that. I'm running at 16 degrees initial and 34-35 total and it runs great. That should get you in the ballpark until you can find what it likes best. Good luck.
Reply
Old Jan 25, 2012 | 07:11 AM
  #3  
BarryK's Avatar
BarryK
Le Mans Master
20 Year Member
 
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
Default

try this:

http://forums.corvetteforum.com/c3-t...long-post.html
Reply
Old Jan 25, 2012 | 05:59 PM
  #4  
goyamaha's Avatar
goyamaha
Thread Starter
Cruising
 
Joined: Dec 2011
Posts: 14
Likes: 0
Default

Originally Posted by BarryK
Thanks Les. And BarryK, wow...that's the motherload. Thanks!
Reply
Old Jan 25, 2012 | 06:30 PM
  #5  
TheSkunkWorks's Avatar
TheSkunkWorks
Le Mans Master
10 Year Member
Liked
Loved
Top Answer: 1
 
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Default

Good info in that thread, but do bear in mind not all engines have the exact same ignition timing requirements, and some BB builds simply won't tolerate too quick of an advance curve (mechanical). That said, I'd agree that 16* initial with 34* total (again, mechanical) should be a very good starting point for you.

Reply
Old Jan 25, 2012 | 07:17 PM
  #6  
midyearvette's Avatar
midyearvette
Le Mans Master
Supporting Lifetime Gold
 
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
Default

Originally Posted by TheSkunkWorks
Good info in that thread, but do bear in mind not all engines have the exact same ignition timing requirements, and some BB builds simply won't tolerate too quick of an advance curve (mechanical). That said, I'd agree that 16* initial with 34* total (again, mechanical) should be a very good starting point for you.

...thats a great starting point, don't be surprised if it really likes 38-40 total depending on which heads you have, open or closed chamber
with your compression where it is, i don't think it would like anything over 40 degrees total
try all in at 36-3800 (slow curve)
15-20 initial
Reply

Get notified of new replies

To Big Block Timing?



Thread Tools
Search this Thread

All times are GMT -4. The time now is 02:33 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 11:09:53


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE