[Fot] engine break-in

[Larry Young]

Another reason for the 20 minutes at 2000 to 2500 RPM is that it reduces 
the stress on the cam.  The highest stress point is on the nose of the 
cam due to the high spring force and small radius of curvature.  When 
running the inertial forces will act counter to the spring force and 
reduce the stress at the nose of the cam.  Another way to reduce the 
stress is to run only the outer springs during breakin.  I have never 
done this, but it sounds like a good idea and it can't hurt.  Installing 
the inner springs is not difficult with the correct tool.
Larry

On 10/29/2010 1:30 AM, Tony Drews wrote:
> Oops - too long, forgot to <snip>.
>
> The 20 to 25 minutes at 2000 to 2500 (with high zddp oil) is key to 
> the cam and lifters.  I do that with every rebuild in the garage.  
> That's usually a great time to have a beer to celebrate and to let me 
> neighbors know that I still have the race car.
>
> - Tony Drews