I just completely rebuilt my SBC. It has a roller cam. What should I do to break this engine in? Should I just fire it up and let her rip or should I go easy on it for 500 miles? Also, what oil should I use 10w30, 5w30? I heard that you should use non-synthetic oil and then switch to synthetic. Any help would be great. Thanks.

 

You should mostly drive it like you intend to for the rest of its life, minus full-throttle accelerations from a standing stop to redline.

I like to get on the freeway and run it at full throttle from 2000 - 2500 or so, up to maybe 4500 - 5000; then let the engine brake the car back down to the 2500 neighborhood; and repeat. Usually needs to be in 2nd or 3rd gear to do this right. Do that 4 or 5 times, then let it cruise for a couple of miles, then repeat the cycle. The acceleration will heat up the rings and help seat them, while the engine braking will create vacuum in the cylinders and pull fresh oil into everything related to the rings.

With a roller cam you can use synthetic from the get-go. (the factory does, and has for decades) Viscosity will depend ultimately on your bearing clearances, but if properly built, 5W-30 or 10W-30 will be fine. I don't get very worked up over "what kind" of oil; seems to me, ANY oil that's new, clean, and a full crankcase, is better than old, dirty, and you can't find it or get it instantly when you need it so the crankcase runs low. IOW, pay no attention to 540rat's rants, the "I only use oil distilled from raw angel tears and alloyed 10% with pure virgin nonobtanium by 10,000 year old gnomes" people who get hung up on "the best" oil even though they can't actually get it except by ordering it and maybe waiting weeks for it to come in, and so on. The benefits of all that, if any, are so miniscule as to be undetectable, over the lifetime of an engine in anything like normal street duty. I mostly use Mobil 1 because (a) it's entirely adequate, even if not "the best"; and (b) I can get it ANYWHERE, 24 hrs a day, 365 days a year, whether hear my house, on the road, in a distant city, or WHATEVER. Every Wal-Mart, AZ, Meijer, etc. has it.

Change the filter after the first couple hundred miles. Fill it with new clean oil before you put it back on. Change the oil & filter after a couple thousand miles, or if it shows any signs of needing it. (metal/dirt, turns black, smells like fuel, etc.) Again, take a look at new-car instructions, and pattern your maintenance after that. It's not necessary, in a street car that a person that would ask this sort of question about in this way would be building, to get all wrapped up in what "all the fast cars" do.

 

Thanks for the help I appreciate it.

 

Personally, I believe 540RAT is on to something, and that not all motor oils are created equal. I completely agree with SOFA's method of break-in, and in doing so, an engine has NO CHOICE but to break in. No synthetic oil is gonna prevent that.
I like Valvoline and Havoline (or NAPA) for conventional oils, and Quaker State (which is actually owned by Shell) Full Synthetic.
I don't worry too much about brands for my roller-cammed daily drivers, but for my old flat-tappet cars, I like the aforementioned...

 

Just a quick word of caution here:

Today, Piston-Rings are produced with different profiles/ shapes available, different thicknesses, different tension ratings, different materials/ alloys, and as a result, different Gap recommendations, and different methods/ time ranges for proper/ fully setting the Ring-Packs.

Some Designs and Materials will set-in very quickly, but often have a shorter life-span.
On the other hand, some take a much longer amount of time to set-in... but last much longer.

Different types of Engine Oils, or Break-In Oils, or Oil Additives are recommended for the break-in process/ setting-in the Piston-Rings.

When it comes to the Small Block Chevrolet Engine (Gen-I, Gen-III, and Gen-IV)...
I have now been using only 3 different Products for Piston-Rings (from Total Seal)...
The same Amsoil Non-Synthetic Engine Break-In Oil, and the same Total-Seal Cylinder-Wall Additive, for a loooong time.

Even with consistent Products being used, Gas-Porting, Compression, Stroke, Forced Induction, and Type of Fuel...
All alter how well and how long the Piston-Rings Set-In.

Why did I say all of this?
It is always best to consult the Piston-Ring Manufacturer with your Engine Combination...
For recommendations for the best possible Break-In results!