I just put together an engine for my race only car. Aluminium headed 360 12 to 1 compression with a solid flat tappet cam around .670 lift and duration at 265 at .050. I just broke the cam in by running it for 22 minutes between 1800 and 2500 rpm. I vary rpm during cam break in. I just installed the inner springs, anything else I should do before next Sundays race? How do ya'll break in a race engine?

Time to run it.

Change oil, look at the filter for anything bad, run the valves again, double check timing, everything tight.

I use tranny fluid on my cylinder walls on assembly so by time it hits the track it’s pedal to the metal. Race time

I always broke them in during the water burnout at Keystone. About 6000 rpm. Seriously, I never broke any of them in. I just put them in and run it.

If you can drive it to the other end of the return road in 1st (if it will hold the engine and not coast) or second gear and run the rpm up to 3000 to 4500 several times and let off completely until it slows down below 2000 RPM and do it again several times to help seat the rings.
If you have enough room and won't get into trouble run it up to or above 5000 RPM in high gear at WOT and let completely off several times to help finish seating the rings
If you can't do that run it up to 5000+ RPM in second gear on the track and let off at least once and then race the heck out of it

At this point the cam is broken in and as my son put on his "uber" dragster

I've certainly taken a fresh engine - with maybe 5 minutes of run time - down the road to a race out of necessity. I prefer to take it to the track, put a couple of 1/8 mile hits on it, take it home and change oil, look at the filter, double check adjustments and valves, etc. before racing it. Be different if it had been on a dyno.

Back in the day, race engines would be stripped after a race and re-ringed (same size) because the walls had assumed their "as-stressed" shape and ring seal would improve. Harley-Davidson did this as far back as 1955.

And this means what? Should us bracket racers go out for a day of Racing and then tear it all apart and rebuild it for next week. Cheese and rice stay on point. Lol. Build it right, race the dog gone thing, and have fun. Don’t over think it.

I've always broke new motors in as they were ment to work and race motors are no exception.

Iowan..Don't know where you are from but when my motor was done we went to Humboldt and beat it pretty good!

LOVE IT!

Up around the Mason City area, about an hour from Cedar Falls Raceway.

Cool!

Read an article about cycle racing. The guy built two engines identical, first one did about tweenty laps very easy. Second, full throttle the whole race. After the "break in" fist bike never could run as fast as the second. After the season tore both down, first one was black, dirty inside, second just like new. The full throttle made the rings seal better so no blow by. The old adage, run it like you stole it off the showroom floor works.
All out and don't look back.

^^^ go to www.mototuneusa.com then scroll down to & click on "breakin secrets". Made a believer outa me.