Well, I know there is about as an infinite amount of ways people break in their engines and everyone swears their way is the only one, but I wanted to ask for some opinions.
I have all the parts for my built and am just waiting to get started.

For assembly, I wanted to use the Ams Oil Assembly lube and for break-in Ams Oil break in Oil.

Plan on installing engine and trans in the truck, Fenders and everything is still off. Throw core support on and brace it to the cab so it doesn't flop. Install radiator and wiring and fire the engine up without the fenders so I have access to the thing to check for freeze plug leaks and stuff like that.

Run the break-in and change filter and Oil. I am not sure for the oil yet. Was looking at a mineral diesel oil and throwing some zinc additive in there as well. Or should I run synthetic with additive from the start? I change my oil very often. Not too sure about the weight either. I ran 20W50 in it before the rebuild, but I am pretty certain that that should not be necessary with a rebuilt engine. Well, on a good rebuilt anyways Maybe a 10W40?

Any input is greatly Appriciated.

 

I don't think you can properly break it in sitting in the driveway. If you want to start and run it some to get things sorted, they usually get it started and run it at 2000 rpm for 15-20 minutes to break in the camshaft and lifters, and then do some tweaks and address any leaks. But after that I don't think you can expect the rings to be properly seated until you get it out on the road and put a load on it.

 

I am aware that it won't be ready to go after the cam break in.

So you saying keep the break-in oil in the engine after cam break-in and then run it on the road with that oil?

I was planning for a few hundred miles break-in time with keeping off the revs. Just not sure If I should change the oil beforehand or after driving it.
I kinda wanted to do an oil change after cam break-in to see if I ate a lobe and need to pull it again.

 

You can change the oil as often as you like. but I would not consider the engine "broken in" until it was out on the road. The procedure I have been told about and usually follow is to get it warmed up, get out on a deserted road, and give it almost full throttle and run it up to the speed limit and then let off and let it coast down, and do that again and again about 10 times. The extra pressure from the 3/4 throttle spurts makes the rings press out against the cylinder walls and helps them seat. They say you don't want to run it so hard that it gets hot, thus the reason for short bursts.

 

I definitely agree that it is not broken in after doing the cam.

Appreciate the input on breaking in the rings though. I was just gonna drive it mellow, but that makes sense.

 

I had my 302 broken in on a dyno. I was a bit paranoid about attempting that at home, so I specifically selected a rebuild shop that had a dyno. I didn't care about the HP numbers so much, but I wanted them to prove their build and make sure there were no leaks or problems, etc. It cost me an extra 500 bucks, but that did get me a full day on the dyno (full day, minus the time to set it up and tear it down, so maybe 3 hrs total).

They primed the oil system with a drill. It was kind of cool...he just pulled the trigger lock, and then let the side handle rest up against the rad hose and the the drill just sat there at full speed for a good 10 minutes or more while he was doing other stuff.



Anyway, they got the distributor all lined up, and the carb full of gas, and man that thing started like it was EFI and then they did the 20 minute break-in (probably 10 straight minutes at about 2000 RPM, and then for the next 10 minutes varied it a little bit with a few revs mixed in). After that, we probably did a dozen dyno pulls while adjusting the carb and ignition, so I was confident that it was broken in well.

We ran Comp Cams Break-In oil for the day, and they told me to leave it in the engine for a while, which I did. Maybe another 300-350 miles or so, maybe longer. I thne switched to that Valvoline VR1 Racing Oil 10w30 for a couple changes...several thousand miles, and then I switched over to Mobil 1 Turbo Diesel Truck oil 5w40 and have been running that ever since. No other additives. I screwed around with ZDDP additives on previous engines and I dunno, it seemed like a pain in the so this time I said I would just run diesel engine oil, or I'll buy some classic car oil or something with higher Zinc levels than regular stuff.

Ya know, I always wonder...people like me (and my old man as well) fuss over oils and other fluids and read and study and buy expensive this and that, and meanwhile, some dude with the same engine will run cheap no name oil and put 350,000 miles on the same engine without ever worrying for a second about it...LOL.

 

Thanks for the input.
That thing sure looks sweet. I bet it drives sweet too.
So it looks like I'll just pre-lube it, fire it up, and break the cam in. See if the oil is a glitter bomb and if it runs smooth. If so, I'll leave the break-in oil in it and run it for a few hundred miles and seat the rings.
Then change oil.
I think I am gonna go with a normal mineral diesel oil and then throw a bit of zink additive in it, just because I am a bit paranoid about the cam eating itself.

 

My drag motor I did the cam break in, open headers, in my drive way then on to the track even with the same oil I broke the cam in with.
Went out a few different weekends with the same oil before I checked it.

If it was a street motor, cam break in in drive and then drive the carp out of it don't babby it and never keep it at 1 RPM for a long time.
Dave ----

 

Thank You all for the input. I have read a lot that you need to take it easy, but what yall have been saying makes sense. And tbh I would have had trouble keeping my foot off anyway

 

I had an airplane mechanic buddy(A&P) describe it this way: all normal oils today have at least the minimums (detergents, etc.) to run a vehicle. The high dollar ones just have more additives; they clean better and take longer to break down. He continues saying the worst thing is taking an I'll treated engine and filling it with super cleaners. Suddenly the engine gets flooded with a ton of suspended gunk. It is like a middle aged meat and potatoes guy going vegan overnight. It ain't pretty.

All transmission guys I've heard say if the fluid hasn't been changed regularly, the worst thing an owner can do is change it. I made the mistake once and in a few dozen miles it wouldn't shift; all the gunk that was holding it together was gone.

 

If the reason you are running a mineral is for Cam protection that the wrong way to do it. Go to a Synthetic. The only case for running a mineral today is if you are counting pennies. There is no case for running a mineral oil in a new engine. It is akin to picking a castor oil over mineral oil.
Whatever you use for break-in oil leave in for a few hundred miles. Most all the break-in oils will be loaded with zinc, and it will take some time for the zinc to get the tribofilms built up on the cam and tappets and and non-roller rockers. So run it for a hundred miles. Then move to a high zinc synthetic. The Mobil 1 Turbodiesel truck 5W-40 or Shell Rotella T6 5W-40 are good choices they both have enough zinc to continue to build up tribofilms. Short change the first oil change after the break-in change say 2500 Miles. The next one do at 4000. The first couple of oil changes the oil will be depositing tribofilms so good practice to short change the first 2 after the break-in oil change so you do not deplete the ZDDP in the oil. After that, you should be good to go to 6-7000 Mile oil changes.
For break-in just vary engine RPM for those first few hundred miles. Regardless follow the rebuilders instructions for ring seating as he is the one that cross-hatched the bore and will know best what needs to be done to ensure proper ring seating.
I have good success following the above with break-ins and getting trouble-free long engine life.
As noted below, this engine was never seen a drop of mineral for it's whole life and had only started using a litre between changes at 600K miles with changes being at 8000 miles and running Mobil 1 5W-30 (factory recommended a 5W-20 but that is too light for any motor IMHO)

 

Always change the oil/filter after cam break-in as it will be full of trash. You don't use SYN on a break-in as you want the extra friction with DYNO for everything to wear/seat together.

DO NOT GAG a fresh engine. Drive it fairly gently making light acceleration and draw-down for a few hundred miles to seat the rings.

 

Okay, that makes sense I might as well switch to synthetic while I know that there is no garbage and oil sludge holding the engine together. I saw that the Ams Oil Z rod stuff has high zink so I was thinking of running that for for the first few oil changes to get give it the best chance. That stuff is synthetic as well, so that would go hand in hand with that.

I think the not keeping it at 1 rpm for a long time makes sense. I have enough open road around here where I can just mess with it.

The break-in oil I ordered is nonsynthetic. I am there with you on the changing oil, even just to see if my cam is floating around in the pan. Would you recommend changing the break-in oil for another round of break-in oil after the cam break-in? (Lot of breaking)
As I said, I was looking at possibly running the Z rod for a few oil changes after the break-in, in hopes that it might supply the camshaft with more zink ofter the first few thousand miles.

I with not Going wide open with a fresh engine makes sense, I think the others didn't mean pedal to the metal, just load pulls to seat the rings.

Thanks for the input again, I like a good discussion.

 

If it was mine (and this is a flat tappet cam?), I would use the break-in oil only for the cam break-in. Dump it as most break-in oils have a reduced detergent/dispersant package. Move to a quality DINO for the driving part of the break-in (rings) (500 miles), drop it and then go to SYN if desired.

Also check any so-called RACING OIL (for street use) to ensure it has the needed packages for street use. A RACING OIL has little as it is dropped frequently.

The DINO oil will allow greater friction to allow all parts to wear into one another. SYN in a factory fill is a result of more advanced machining/assembly tech that would be hard to duplicate, especially with older tech engines.

And of course a quality filter, MOTORCRAFT or WIX. No RACING FILTER for the street. Ensure the CCV (PCV) SYSTEM is designed/working correctly and has the proper fuel curve.

Desired current oil is classified as API SN PLUS.

All of the above is IMO. Anyone else's experience/mileage may differ greatly.

 

I appreciate the input greatly. Especially giving your reasoning for everything.
Yes, It is a flat tappet cam, probably should have mentioned that at the beginning.

What you are saying definitely makes sense. I have two Wix Filters bought that I will be using.

With using Mineral oil for the ring seating, I can definitely see the argument for one or the other.
From what I have been reading up on and what has been said. I think that I will definitely run a synthetic long term.
As for the engine break-in, I can see the reasoning behind the mineral. I think I will run my mineral diesel oil that I have been using (has that rating) and throw some zink additive in there. Run it for the break-in and then change over to a synthetic blend.