Your break in procedure should be followed as the ring manufacture states it should be for your application. Some companies and their rings require a slow break in. Others state to put the car through hard acceleration. Hastings states for their CI rings to be run in on the car through WOT acceleration from moderate RPM(~2000) roughly 10 times to seat the rings in. This is on new cylinders(bore and hone) not refit. The rings will continue to seat in a bit more over the next 100 miles or so. It’s based on ring composition and cylinder composition/coating. Porsche nikasil bores with Goetz chrome plated rings for example, require moderate rpm and cylinder compression to seat the rings fully. They’re using a hard faced ring on a VERY hard faced nikasil coating. The older Aluasil ring/bore setups were completely different.
Look at F1 engines. Every engine is broken in and run on a dyno prior to being used in a chassis and are often put through a rigorous digital course test as well. They’re breaking in to their specs.
Lower end bearings will polish in rather quick as long as the journals were polished properly(good Ra, no crown, etc) and in the proper direction. What you don’t want to do is lug the motor as this can gall the surface of a new rod bearing VERY easily with excessive loading.
I always do a ~15 minute motor run in at about 1500rpm first to run through a thermal cycle. Flush the oil out to rid of engine prelube and particulate. I add one quart of MMO to the fresh oil going in and then I run the motors through a moderate pace on the dyno or track. Forced inducted motors running substantial boost should stay away from running full boost at first, but should not be afraid to put boost through the motor at all.
Ra is the average roughness, usually with a 2rc or Gaussian filter. Something could be microscopically rough, but as long as it was uniform it could have a relatively low Ra.
Rt however is the distance from the highest peak to the lowest valley in the sample length “lambda” and is generally more representative of the actual roughness of the sample.
since is is very difficult to achieve a low Ra, Ra is the standard measurement of roughness in industry.
Numbers here are important.
A good machined part, when requested could have a 16-32 Ra
A ground part can be 4-8 Ra cost effectively
Parts can be ground from 1-4 with special care and great expense.
Generally it is less expensive to request a 4 Ra finish from grinding, and then polish down to a 1-2 Ra.
When I was doing artificial heart work, we would grind from 2-4 and then have it sent out to a specialty medical polisher and we would get parts back with Ra numbers from 0.3 to 0.9 For reference 2-4 is mirror-like.
With this surface finish the blood will not stick and less thrombosis and hemolysis is likely to occur.
There is a strong connection between surface finish and strength.
run it they way your gonna use it just not as much ,in other words get on it but dont let it coast to slow down witout bein in neutral for a little while,run dyno oil in it for 500 miles then drain it refill wit dyno for 1000 miles then have at it .pretty much within a few minuetes everything has seated just have fun wit it
There’s as much speculative information here as in most brake related posts on this forum…
Break in procedures are directly related to the ring composition and cylinder setup and as such you should follow the ring(and/or piston) manufactures specs for break in. They have spent the money doing the research in this area and as such know what is best for your application. Different types of rings and cylinder platings require different types of break in steps. Gas ported pistons vs non ported, low tension rings, surface plating, etc, etc all have an impact as to how rings will seat and all require different procedures to get the best possible seat.
If you’re using a setup outside any pre-determined realm of the manufacture, then it’s up to you to do the work necessary to determine the best possible break in procedure. Otherwise just stick to what is suggested by the ring/piston manufacture.
1320-20V correct on all accounts. I talk “Ra” as it’s typically used in the automotive/engine field where you are calculating/determining the average roughness across a given length of surface whether it be a bearing surface, block deck, or head sealing surface. I have a second hand SRG4K which even it tends to be way more than what I need here but get’s the job done nicely. Tests other things like rq and rz that I haven’t bothered to get into(you would probably know). I hardly ever use the damn thing though, mostly when setting up and testing the cut of new tooling or infrequent material( beryllium copper valve seats for example)