Well I'm getting my car back today with new valves, springs, and retainers (please don't ask why, it's too painful a story). The head was taken off to do this work.

The technician told me that another break-in isn't necessary, but I'm sure to be very cautious at first. So, all you car gurus, do I need to treat the engine like it's brand new again? I don't know if I can handle this born-again virgin thing.

Thanks!

 

I don't think we can advise you until you tell us what happened to the car.

 

Break in is primarily for ring seating. Unless your pistons were removed from the bores, you should not have to repeat another lengthly break in. Just to be safe, I would run it fifty miles or so under moderate loads just to get the valve guides, rockers, springs etc. settled in before redlining it.

 

Exactly right!

Break in also helps mate or wear in the main bearings without overheating and glazing them. That is of no concern in this case though.