Speaking of facts, even the cam/lifter manufacturers tell you there's no break in procedure for a roller cam.
Perhaps by some off chance some manufacturers might differ? But no break in is the norm.
Paragraph B-c: http://www.cranecams.com/pdf-tech-ti...failure811.pdf

 

I have to agree with no break in needed. I went 9's with no break in and a 355. Solid roller in the 255* area w/ about .650" lift. I broke that motor in in the staging lanes at Super Chevy. All it did was get faster as it broke in. Made it a pain in the rear to dial a number though. I have NEVER broken in a roller. I've have at least four of them.

 

New one on me too. I've never seen a cam maker who reccommended cam break in with a roller cam. What is involved with cam break in on a roller? Is it the same 20 min. at 2500 rpm?

 

It is proven that rollers do not need break in to run. I break in all cams because I change the oil and filter for any other components that may break in but looking at the roller cams after run for 20 min.@ 2000 rpm with no variance- there is still a unique wear pattern on the sharp edges of my roller cam so when any metal that is slightly not perfect within .000whatever that will smooth out so I chose to break in all cams with lube and zinc etc. since the oil change and filter are needed anyway from the rest of the parts making first contact as well. I just reccomend it. But it is good practice I believe for any cam to employ break-in procedure: running engine, ring sealing, seating valves, initial roller tip to stem contact, proper lubrication lube: zinc moly etc. flush engine change filtration oil etc. inspect old filter. double check cam endplay after engine run. There is some variance to materials in cams and I have not accounted for this (as a side note).

 

Do you disassemble your engine after breakin to check lifters, and end play? Sounds like a lot of work after putting it all together and running.

 

The best kind of engine break-in is a run-in on the street. An in the garage break-in (unloaded) doesn't seat the rings to the cylinder walls nearly as well. And once you do that, your window of opportunity starts to close. As tempting as it may be, aside from the flat tappet 20 minute break-in, never run a newly built engine until you're ready to take the car for a drive.

 

wow well ima thinking a break in is best. but this is my first ever motor build do how do you go about the break in procedure? im in no hurrey whatsoever on this motor i will happily take things apart to do this properly i would rather not be wasting thousands of dollars.

 

and i had already planned to port polish everything

 

If I do break one in I turn the idle up to 2g or so and let it sit while I go over the fuel lines and watch pressures and temps.

 

Don't break in the engine, run it in. Look up the principles behind what it is that forces the rings against the cylinder walls, then you'll understand why.
Roller lifters need to be "broken in" to the cam, as much as the casters on your office chair need to be broken in to your floor, if you get my meaning.