Engine Break-in
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
The running of the hand built engines, like the LS7 and the LS9 are both with Mobil 1 from the get-go. The spin test they go through is a diagnostic process that measures a number of items to ensure the engine doesn't have any issues. The firing test or hot test, is just that, a test, nothing to do with break-in. The new LS9 uses slave plates for the honing process. All of this is to ensure the bores are round and true from the very start. As stated before, the break-in time on current engines is much shorter then years past. The time for a break-in is hours, 4 to 8 typically as compared to thousands of miles as some suggest.
If you are having an engine rebuilt, make sure the shop has the latest in honing equipment and using deck plates and has a skilled operator.
Piston to bore fits and newer piston ring materials make the difference from the past ideas of needed long slow break-in compared to todays much shorter break-in times. If you wish to do a long slow break-in you are not hurting anything, but it really isn't needed.
Just my humble opinion!
Eric D
If you are having an engine rebuilt, make sure the shop has the latest in honing equipment and using deck plates and has a skilled operator.
Piston to bore fits and newer piston ring materials make the difference from the past ideas of needed long slow break-in compared to todays much shorter break-in times. If you wish to do a long slow break-in you are not hurting anything, but it really isn't needed.
Just my humble opinion!
Eric D
Thread Starter
Drifting
Joined: Feb 2006
Posts: 1,877
Likes: 1
From: Ok! So you don't believe in conspiracies, but will you acknowledge the possibility of there being coordinated activities in secret places? Texas
It seems the consensus is to run the engine 4 to 8 hours at various loads/engine speeds, but with no sudden loading and nothing over 4000 rpm. Change the oil, then let her have it.
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
I would also suggest when you change the filter and oil the first time, I always like to cut open the filter to have a look-see on the inside along with running a magnet around the oil from inside the filter. If it all looks clean then let it rock!
Regards,
Eric D
Burning Brakes
Joined: Sep 2004
Posts: 800
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From: Tucker Ga
Safety Car
Joined: Jul 2001
Posts: 4,661
Likes: 67
From: Ocean Springs MS
If your engine is built to similar tolerances as the factory engines, break in is not critical. As mentioned they are run on a dyno right off the assembly line. I think the owner 's manual still says just to vary the speed, and not drive long at a constant speed or high RPM for 500 miles.
Just remember, the GM procedure in the owners manual, shown below, is not just for the engine, but also for the differential, tranny, and brakes (as noted in the 3rd bullet.)
"Your vehicle doesn’t 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).
* Don’t drive at any one speed -- fast or
slow -- for the first 500 miles (805 km).
Don’t make full-throttle starts.
* Avoid making hard stops for the first
200 miles (322 km) or so. During this time
your new brake linings aren’t 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."
