Don't forget the pistons &wrist pins . also , if the finish hone is correct & the materials in today's rings , break in is pretty much immediate !The rpm is not for cam break in, it’s for adequate oil splash on parts that get lubed by splash. Like the cam, pushrods, rockers, valve tips.
In the car break in is just like on a stand.
What about how long should I let it idle before I crank it up to 2500? Does it matter? And is this all i need to do to increase cylinder pressure to seat the rings?Hook up a rad, fuel line from container to carb And crank it up to 2500 rpm for 10minutes.
Assuming you have a carb that is.
Charged battery will be good for 10 minutes too.
Do you not believe in breaking it in on a stand?I'm no expert by any means. But I did a bunch of research last week before I fired my second engine rebuild ever. With a roller cam breaking that in is not really an issue, the thing that's really important is getting the Rings to seat. This is best done in a car, or on a dyno. But others will chime in about it being done successfully on an engine stand..
to fully break-in rings you have to increase load...as in resistance to turning the crank. Can't do that on a stand.What about how long should I let it idle before I crank it up to 2500? Does it matter? And is this all i need to do to increase cylinder pressure to seat the rings?
I would now. I learn more here each day. I just installed an ATK reman into a car the other day. It sounds terrible, and they want me to open it up and work to rebuild a rebuilt motor. I wish I would have broke it in on a stand! What a total piece of crap...Do you not believe in breaking it in on a stand?
Yea , like the OEM's do this with every car down the line LOLto fully break-in rings you have to increase load...as in resistance to turning the crank. Can't do that on a stand.
Roller cam engine preliminary run-in on a stand, do it as has been mentioned...light it off right up to fast idle/2000 rpm speed, run 7-10 minutes or so to get it good and heat soaked checking for leaks as it runs.
After that, without access to a dyno to do load testing, it needs to go in the vehicle to properly finish the ring break-in...
10 runs, middle gear in trans, 20-50 mph 3/4 throttle and then coast back down to 20 mph still in gear using engine braking to slow down with short cool off stretches between each load run, then..
10 runs high gear, same type of deal 30-60 or 40-70mph full throttle with engine braking back down to lower speed. Speed range you use will depend on cars rear gearing and tire size, but the gist is you want the engine rpm to be within 700-1000 rpm of you intended max rpm at the end of each power load run in this high gear phase of load cycles.
After that, it should be good to go.
You want to avoid a lot of idle time on the run stand or you risk glazing the ring seal.