Looking for input on engine oil preference for a new motor. Do you prefer engine break-in oil (e.g. Brad Penn Oil) or regular oil (20W50 OR 10W30) with ZDDP additive on a freshly built Mopar 340, 440, etc..

How long do you like to leave the oil in before the 1st change?

Last one I did I went with Valvoline 10-40 and a bottle of GM EOS. I changed the oil after a few miles so I could see if there was any metal in the oil. This was a mild cam on a driver. If I had a serious cam and valve spring package I would consider the specialty break-in oils.

Some amount of very small metal flakes are normal on a brand new engine on the first oil change or two. Those small particles should recede with each oil change as time goes on.

I also run a filter mag on the oil filter.

hi
if you dont want to do it all over agin use amsoil 30w brake in oil .

it cost a little more but i leave it in up to 1000 miles then switch to valvoline 10w/30 VR-1 !

use a napa gold or wix filter only !

never had a prob with this combo !

No info on the best (breakin) oil but I would change it right after the 30 minute breakin along with a wix filter. Some good ring breakin info, go to www.mototuneusa.com & scroll down to & click on "breakin secrets".

I have always used Valvoline VR1 racing oil and a bottle of zinc additive when breaking in a new eng and flat tappet cam. I have never wiped a cam lobe. Course I don't build as many engines as a machine shop but my sons eng and my last 2 engines were all broken in that way with no problems. I also use the Valvoline VR1 racing oil all the time in my engines. Ron

I use Brad Penn now called Penn Grade in 30wt.break in oil. I've never wiped a cam either and leave it in for a few hundred miles then change over to Penn Grade 20W-50 which is also high zinc oil.
Ron

Last few of mine have been flat-tapped (hyd or mech). Haven't used a specific break-in oil, but have added a bottle of the GM EOS. (I bought the last 10 bottles of that in my area a few years back, as I'd heard the formula was being changed.)
Nothing crazy on valve spring pressures, though those engines were pretty stout - usually around .510-.540 lifts, 130# seat pressures & around 400# max - but zero problems with any of them. Didn't remove any valve springs (I always use double springs). Napa Gold filters, either the Gibbs/Driven "HotRod" oil or Lucas, 10W-30. Local engine guru who does a lot of circle-track stuff sends oil out for testing & says the Lucas stuff is very consistent quality & amounts of ZDDP & etc.
Initial break-in is usually around 30 minutes, varying RPM & watching everything like a nervous Mom, haha.
After that I like to pull the filter & cut it open. Generally change the oil within a few hours or 100-ish miles, cheap insurance.
You'll generally see some debris in the 1st filter, maybe including some particles off the valve springs.

I used to use EOS years back when they still sold the good stuff. I don't do many engines so these days I pony up for the dedicated break in oil.

Driven Racing Oil 01806 - Joe Gibbs Driven BR Break-In Motor Oil
$7.99 a quart from Summit. Or use another brand of oil strictly developed for break-in. It doesn't cost any more, or just a little bit more. Use the right tool for the job!
Why mess around with regular oil with additives that might fight each other, or Diesel oils with very high detergent levels that prevent the ZDDP from sticking to the parts?
I also don't understand the 20W50 oil after break-in. Maybe you should just pour some gear oil in because it's thicker? Remember that the oil has to be thin enough to get into very small clearances.

R.

I do 2-3 engines a year all flat tappet mopar's either for myself or my buddies i run a good name brand oil 10w30 or a 10w40 with some kind of zinc additive added to it, never have wiped a cam ever. i think a lot of issues are lack of prelube not getting the motor fired off right away not priming the engine or not making sure the lifters turn in their bores. another thing is too much spring pressure for break in. i take a lot of time to ensure the lifters turn freely i hone the lifter bores too most of the time. i break in the cam for about 20 min then take it for a couple of drives no more than 50 miles or so then dump the oil put in some fresh with a new filter and another zinc additive and that's it. this has worked for me others may have other stuff that works for them.

X2 on checking rotation with a speed handle/inner spring removal/immediate fireup. Quality for the most part is declining so anything to put the odds better is a good plan.

I'm with you there. I always ran 10w30 in mine and never had a low oil pressure problem. I tried 15w40 once and on a cool fall day the engine labors quite a bit harder pumping that stuff. Enough to notice.

you break-in without the inner valve springs?

I use some break-in lube on the camshaft and then run Shell Rotella 15w 40 diesel oil, for muscle car engines. The diesel oil has ZDP additives still in it. They just changed the formulation, but I called Shell and it still has enough ZDP for flat tappet cams. Rotella is reasonably priced, and available everywhere. The specialty oils are great, but cost more, and what do you do if you need a quart out on the road? The other issue is be careful adding to much ZDP because it can actually cause issues it you add too much. Say a specialty oil and additive on top of it.
https://www.hemmings.com/blog/2012/10/18/tech-101-zinc-in-oil-and-its-effects-on-older-engines/