C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Setting Timing on L98

Thread Tools
 
Search this Thread
 
Old May 22, 2025 | 09:06 AM
  #1  
Brandon Iron Smithe's Avatar
Brandon Iron Smithe
Thread Starter
Advanced
Liked
Loved
Community Favorite
 
Joined: Feb 2021
Posts: 79
Likes: 16
From: San Diego, CA
Default Setting Timing on L98

Since I haven’t gotten it to fire up yet, should I disconnect the EST before I try again? Reverifying that I stabbed the dizzy right and the plug wires are correct. If it is out 180°, it will backfire through the intake, correct? Also, can a DUI cap be used on a stock dizzy? Thanks.
Reply
Old May 28, 2025 | 07:54 AM
  #2  
Magnet's Avatar
Magnet
Pro
25 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Feb 2001
Posts: 509
Likes: 15
From: Calgary, Alberta, Canada
Default

I would leave the EST plugged in to ensure you get the L98 running and up to temperature to begin with. This will confirm you have the correct TDC. Then, turn engine off, unhook EST connector by the brake booster and start the car to time the engine. I timed my distributer to 6 degrees then re-connect EST.
Reply
Old May 28, 2025 | 11:05 PM
  #3  
C4industries's Avatar
C4industries
Racer
Photogenic
Liked
Loved
Community Favorite
 
Joined: Feb 2024
Posts: 269
Likes: 113
From: New York
Default

Originally Posted by Brandon Iron Smithe
Since I haven’t gotten it to fire up yet, should I disconnect the EST before I try again? Reverifying that I stabbed the dizzy right and the plug wires are correct. If it is out 180°, it will backfire through the intake, correct? Also, can a DUI cap be used on a stock dizzy? Thanks.
Pull the #1 spark plug. Put your finger over the hole while you have someone turn the engine over by hand. Feel for compression as the timing marks come to TDC. If you don't feel compression it means you're on the exhaust stroke. Keep rotating the crank until you're on the compression stroke at TDC. Then remove the distributor cap and verify the rotor is pointing at #1 plug wire position.

If that all checks out, verify that you have spark by grounding a plug to the block and cranking the engine over.

What's a "DUI cap"?
Reply
Old May 29, 2025 | 01:07 AM
  #4  
spaceweasel's Avatar
spaceweasel
Instructor
All Eyes On Me
Liked
Loved
Community Favorite
 
Joined: Jan 2019
Posts: 167
Likes: 33
From: Connecticut, USA
Default

Originally Posted by Brandon Iron Smithe
Since I haven’t gotten it to fire up yet, should I disconnect the EST before I try again? Reverifying that I stabbed the dizzy right and the plug wires are correct. If it is out 180°, it will backfire through the intake, correct? Also, can a DUI cap be used on a stock dizzy? Thanks.
I use a DUI cap and coil, and their fancy red sleeved plug wires in my '89. Good stuff.
Reply

Get notified of new replies

To Setting Timing on L98





All times are GMT -4. The time now is 08:12 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 15:43:40


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