I think there are a number offactors to be considered here -
Racing engine life is measured in hours not years - and so what's good for them may not be ideal for road cars.
Its a brave person who strains a new engine if he thinks he may have to pick up the bill if it breaks!
The tolerances on a new engine should be much more consistent than those achieved on reconditioning. I might be tempted to try thrashing a brand new engine - but an overhauled engine - no.
When I've had new or recon engines I've been careful for the first 200 or so miles and after that I have gradually stretched them - with short bursts of power but easing off again afterwards. I gradually extend the loading and after an oil change and a few more miles I'll run it flat out at about 1000 miles which I find usually seems to improve things considerably.
I can't claim any particular merits for this system except to say that I've never had an engine sieze!
New car - Best Break-In procedure?
Moderator: RichardW