I've just had ARP conrod bolts fitted to my S50 B32 motor (rev limit has been raised to 8k and I am taking no chances).

As part of the upgrade, the bearing shells were replaced at the same time since everything was apart.

Question I have is does the engine need to be run in? Bores haven't been touched and everything was done with engine in situ.

It's running Silkolene 10w50 at the moment but I'm wondering whether I need to keep below 4k (or similar) for the first few hundred miles.

Usage is mostly road with occasional track although the 8k limit and ARPs were purely for track action...

Run it like you stole it. Even with a new engine, I don't have the luxury of breaking it in. It gets warmed up, check for leaks and then loaded in the trailer. From there, it gets run hard until the next rebuild.

Run it like you stole it. Even with a new engine, I don't have the luxury of breaking it in. It gets warmed up, check for leaks and then loaded in the trailer. From there, it gets run hard until the next rebuild.

LOL - wondering whether track and auto was right for this thread! Just figured rod bolts would be a track or FI thing so decided to post here for most relevant experience.

Car is predominantly a road car so waiting until a few hundred miles have passed isn't a big deal - just not sure if I need to do it.

Does that change anything?

sounds like you will do it if you need to or not. Just drive it on the streat normally.

I have found that the best motors are broken in hard. You will make more power and use less oil. So drive it hard with lots of variation in RPM's.

Rings/CylinderWalls and Lifter/CamLobes are the only parts of your engine that have a break in associated with them.