Fresh slant 6 here ready for 1st fire. '74 motor so solid lifter from factory.
0.020 over, new pistons and rings, reground original cam
Don't see anyone nearby that has Penn, Gibbs, etc specialty break in oil. I do have 2 bottles of COMP break in lube on the shelf.
Been a while since I built a flat tappet engine.
Is the flattering lobe issue a new/used cam issue? This is a reground original cam.
Done by Oregon cams,it's their #819.
I do have new lifters but they're probably 20+ years old. Plan on changing oil right after cam run in.

your likely to get a lot of different opinions on this one. I typically use Valvoline VR-1 with an additional additive. Your spring pressures are probably low compared to a high lift /duration cam so that will help as well. Get it up to 2K as quickly as possible, set the timing so it sounds good and keep a close eye on the temp. depending on ambient temps It may help to have a good sized fan and a hose ready if needed to keep the temp under control. Give it a good 20 minutes or more.

I would drop Oregon Cams an email asking this.

There is a growing trend of smart builders stepping away from additives. The belief is that they can and do clash with the additive package that is in the oil itself.....to the point where the oil actually protects LESS than just the oil would on it's own.

There is a product called Cam Guard for Airplane engines. Give a look at it and like already said call the cam people.

Cam is what they used to refer to as an "RV" cam. For springs I went with stock-for-a-318 ones, which are slightly heavier than stock original/6 ones. This is in a truck, probably will never see over 3500 rpm or so.

It didn't used to not be necessary and then it became a thing. My guess is that it is mostly marketing but I could be wrong. Personally I don't use it on anything I build but I do know guys who swear by it. It would cost a ton of money to answer the question and the answer would most likely piss off some big boys who make a lot of money selling things so I doubt the test will ever be run.

Best bet if you want an honest answer is to find an engineer who works in engine development at an OEM and ask if they use break in oil for production engines. From what I've heard, they don't. Factory fill with synthetic and ship them out the door.

Difference is that todays and for a long time these have been roller cams going out the door from the OEM's. Pretty sure there is no OEM engineer that has any recent experience with flat tappet cams in a production environment.

Myself I don't worry about it, but the only cam I am running right now is a flat tappet solid lifter cam in a Chrysler flathead six that has just about no valve spring pressure to speak of and a very low red line. It is my opinion that valve spring pressure and RPM are the biggest factors and my engine has practically none of either. I'll coat it with STP and run it.

That flathead is probably the closest thing anyone here has to a /6 like is the subject of the question.
I know that there are several components to the question, and one I was "going after" was on the subject of specific category of cam used. Many seem to key on what's current/ roller cams vs flat tappet.yes there are other considerations that will play into the "right" answer for sure. But I'm looking at a brand new current production flat tappet cams vs in my case a reground, well used original one. Also does solid lifter like my /6 runs vs a hydraulic cam play into the answer?
Does anyone know how much zinc is in current "SP" oils? It seems that is all I can find.
Is (commonly available) diesel oil any better for flat tappet cams any more?

Back in the day (50 years) iirr engines came with non-detergent oil, after 500 miles it was changed to detergent, 30 or 40 weight. Nothing like out there today.

bu the question is did that none detergent oil have ZDDP in it? My guess is yes as flat tappet camshaft failure was one of the reasons it was added to the oil somewhere in the 30's according to current information. Previously read info claimed 1920 or so.
Also 50 years ago was 1972 and I believe the era you were referring to is the 1940- to early 50's

Agreed to call the cam people but honestly I would use as much zinc/ZDDP as possible. Break in oil has that in it.


Old oil had lots of zinc/ZDDP in it and helped with flat tappet break in. New engines use roller tappets/rockers for friction reduction but as a side bonus need less zinc/ZDDP in the oil. The feds a few years back required a reduction in zinc/ZDDP supposedly to help lengthen the life of Catalytic convertors. I believe it was to cause old engine to wear out faster forcing you to buy newer crapboxes.

Once the cam is broken in (500 miles-ish) you can swap oil and use what you want, but for the break in I would use the break in oil or additives.

On one side you may waste some money, on the other side you will be tearing down, cleaning everything and replacing the cam/lifters. Add to that lots of work and collateral expenses, oil, gaskets, etc.

Congrats on the leaning tower of power Often they are overlooked.

My advice is to not go bananas with zddp.

Much above 1400-1500 PPM is rather well documented over many years to cause corrosive wear when the additive is exposed to moisture and high temperatures and degrades into an acid, spalling, pitting, bearing flaking, especially if subjected to regular passenger car oil change intervals.

It would probably be fine to exceed 1500 for break in only, and then drain. Similar to how some of us would add a little more than recommended GM EOS to
Valvoline racing or Castrol GTX in the '80s for that purpose, but the idea is to break in and then dump it fairly quickly because of the above problem.

Just remember my solid tappet are of the mushroom variety. No idea if that wold make a difference though. I just run off the shelf 10w30 on the original engine, which I have no idea how many miles are on it. The 230 I am building to swap in will run the same. Remember the stock valve spring pressures for my engine are 107-115 open and 40-45 closed. Pretty wimpy. Cam has .375" lift, intake duration at .050 is 208, exhaust duration at .050 is 210, advertised is 250/272 pretty wimpy.

make sure the lifters rotate in their bores before you button it up.

seen and heard of many engines crapping out on break in without proper oil in Flat tappet cam configurations. Bradd Penn has breakin oil. Also oil after for flat tappet. Valvoline ZR1 is also good after break in. I use Bradd Penn and had no issues with for years. I don't use an additive as I feel it "may" not mix /react well with chosen oil.

Dodge shop 1970, so 52 years. Other than brand Oil selection was next to nothing then.

IMO break-in oil is most important on a new or rebuilt engine for piston ring to cylinder seating/seal. Yes cam lubrication is also very important a reason there are special initial cam lubes out there but proper piston ring break-in for good seating takes more hours and miles. I could go into lots of stories and experience with engine oil consumption, glazed cylinder walls and oil burning from high friction modifier engine oil use during break-in. I put a new Mercruiser 5.7 liter V8 engine in my boat and Brad Penn break-in oil just for seating the piston rings.

https://www.onallcylinders.com/2018/05/18/ask-away-jeff-smith-cylinder-wall-glazing-get-rid/

From the article:

"So the obvious message here is to properly break in the engine using high quality lubricants designed specifically for engine break-in.

There are dozens of boutique engine break-in oils and several companies, like Driven Racing Oil, offer different styles based on viscosity and application.

It would take perhaps an entire story on all the different break-in oils and why each has a place, but perhaps among the important points is that sufficient levels of high-pressure lubricants like zinc dialkyldithiophosphate (ZDDP) is more important for proper break-in of a flat tappet cam than for ring break-in. In fact, levels in excess of 1,500 to 2,000 parts-per-million (ppm) of ZDDP can contribute to cylinder wall glazing—especially if this oil is combined with excessive engine idling for an excessive period of time.

So be careful because too much of a good thing like ZDDP can create poor results."

Generally, break in oil is very low on detergents, which counteract the chemical bonding of the ZDDP and other anti-wear additives. You also have to consider you need the piston rings and cylinder walls to mate to each other. I have no idea how mixing chemicals together in your crankcase are going to affect your cam and your rings. I'd stick with specific break in oil. My Lunati cam came with Joe Gibbs Racing Driven cam lube, so I just got some of their break in oil from Summit, along with their Hot Rod oil which is designed for old cars with flat tappet cams that may sit a long time, like through the winter, without running.