Do we still "run cars in"

[Incredible Sulk]

I used to build race engines professionally and we found that running in fast tends to result in more power and lower oil consumption than running in gently. Our engines generally got 10 minutes on the dyno to warm up and check for problems followed by a series of full power runs to nail the set up. Once that was done, we'd drop the oil and consider them run in. If I build an engine for myself and don't have access to a dyno, I do pretty much the same thing. Warm up and thorough check over followed by a decent thrashing on the track/road (in so far as conditions will allow). The last few engines I built for myself (a rally spec Ford Kent, a Suzuki GSXR750 and a '55 Triumph 500 twin) all got hammered from day one and have been faultless ever since. Having said that, I can generally spot potential problems and stop the process before the internals start trying to escape through the crank cases. YMMV.

The engine in my TVR is being rebuilt at the moment after which the map will be tweaked on the dyno. After the full power runs on that I don't suppose there will be a lot of point in running it in gently

[Argee1977]

First thing i'd do is check the max speed you can get in each gear, including reverse, after that just drive it like you stole it.

[Richard.]

IO360 ?

IO-550