Good luck with the new long block! 
Balancer Failure
Thread Starter
Racer
Joined: Sep 2008
Posts: 442
Likes: 0
From: Peoria Arizona
Balancer Failure
Update on my C6. I am the unfortunate guy who had a balancer walk off the crank; had the bottom end rebuilt and 2 days after the rebuild the engine seize up. Well, I got it back yesterday. So far so good. The dealership dropped a long block into it. My vette has 61K on it but the engine has, 70 miles on it. Just like new. 
Anyone know what the break in is?
Anyone know what the break in is?
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Well, break-in on a new car is 500 miles. Personally, I would vary the speed and power over that time frame without going too high but lots of different speeds and loads.
Burning Brakes
Joined: Sep 2008
Posts: 943
Likes: 0
From: Ho Chi Minh City
Le Mans Master
Joined: May 2005
Posts: 5,865
Likes: 2
From: Hope, Arkansas - '07 LMB Coupe
Cruise-In VIII Veteran
Here's the procedure recommended in the owner's manual:
New Vehicle Break-In Notice: Your vehicle does not need an elaborate break-in. But it will perform better in the long run if you follow these guidelines:
• Keep your speed at 55 mph (88 km/h) or less for the first 500 miles (805 km).
• Do not drive at any one constant speed, fast or slow, for the first 500 miles (805 km). Do not make full-throttle starts. Avoid downshifting to brake, or slow, the vehicle.
• Avoid making hard stops for the first 200 miles (322 km) or so. During this time your new brake linings are not yet broken in. Hard stops with new linings can mean premature wear and earlier replacement. Follow this breaking-in guideline every time you get new brake linings.
Following break-in, engine speed and load can be gradually increased.
• Keep your speed at 55 mph (88 km/h) or less for the first 500 miles (805 km).
• Do not drive at any one constant speed, fast or slow, for the first 500 miles (805 km). Do not make full-throttle starts. Avoid downshifting to brake, or slow, the vehicle.
• Avoid making hard stops for the first 200 miles (322 km) or so. During this time your new brake linings are not yet broken in. Hard stops with new linings can mean premature wear and earlier replacement. Follow this breaking-in guideline every time you get new brake linings.
Following break-in, engine speed and load can be gradually increased.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Race Director
Joined: Jun 2005
Posts: 10,909
Likes: 2,701
From: Phila Suburbs 2023 C8 & 2013 650ix
No. Drive it conservatively for the first 500 miles and vary the rpms.
Melting Slicks
Joined: Aug 2006
Posts: 2,409
Likes: 129
From: Fairview Heights IL
But that's the same dealership who hired the maroon that destroyed your first engine, so there's definitely room for doubt.
Safety Car
Joined: Nov 2007
Posts: 4,144
Likes: 391
All new corvette engines were started at the factory so the real break in was on the factory dyno. Your new Crate engine was (maybe not )not started. You might want to go easy the first few miles. Do a few starts, shut off, and warm ups, to get all the parts friendly with each other without creating hot spots. Big area of concern on new engine start up is the cam and lifters. Pistons rings usually set in the first minutes. Bearing clearance, if done correctly is a non issue.