mark b

I just put a remanufactured/new engine in my Vette and want to go to the track with it.. Is it safe to drive it hard or should I wait for a while before pushing the engine? the break in procedure just says vary your speed for 600 miles, dont stay at one speed too long.. On the track speed varies all the time.. so would it be safe?

FKING1

I put about 500 miles on my new crate 383 before Autocrossing.
Would recommend the same for yours IMO.
1000 would be even better.

GettReal

big debates on this question. I just had a new motor go in and broke it in on the track. I short shifted for a lot of the day, but 2nd day out drove it like I stole it

Black89Z51

Track usage is a pretty good break in. You're never at the same RPM and you accel and deccel a ton. That will seat the rings real nice. I would use dino oil for the first day, then switch over to whatever you plan on using.

TJM

No directions from the MFG?

GM offers 13 points on break in, but then they warrant the motors?

Part of it is a few specific acceleration routines to seat rings.

Then oil change and a PF25 AC Delco filter and 10w30 standard motor oil. 500 miles on normal drive With No WOT.

Not the sort of advice you want but that is what GM would sau.

TJM

Gering

mark b

thanks guys.. the engine is under warranty 3yrs unlimited miles
I really want to drive it on track I dont think I can wait ***** footing around with it.. LOL so if i shift it at 4000 rpm is that ok?

and right now it has 15/50 oil in it for 600 miles and then Ill change it

moespeeds

http://www.mototuneusa.com/break_in_secrets.htm

This is how I've done every car and motorcycle I've ever had, including my race bikes.

69427

That's pretty much what I did with my current engine.

larryfs

GM runs every motor at WOT before it leaves the plant. break-in is obviously a non-issue.

TJM

The issues is the 3000 lbs it is lugging around. They also specifically state in writing, not to run at WOT, so what to believe?

They also void the warranty if your on a track?? Doubt the GM police will catch you there, though!

SouthernSon

The number of heat cycles counts for a lot. Let engine come up to operating temperature and then cool off completely (several hours). No more than 1/2 throttle and 1/2 rpm range for a few hundred miles. Ideal situation would be cool temperatures and driving each day 20 miles through a city for a month. This may not be necessary for all engines considering there are different tolerances for the different builds but it sure can't hurt.

Painrace

Race engines are built and hot dynoed with no brake in. But, they are used for one or two races! However one to two races could equal a number of street miles.

Jim

Black89Z51

If it hasn't been already mentioned, you can ask this question 100 times and you will probably get 70 different answers. A lot of people are terrified to open it up. In reality, after the first hundred miles (significantly less on a track) the rings are fully seated.

All the break-in does is wear the sharp peaks cause by honing the cylinders to have more of a plateau than a peak. The rings accomplish this.