with a flat tappet cam I would change the oil at 100 miles and use brake in oil on that oil change. next go 500 miles then change to what ever you want to use with a zddp addative.

 

Okay....I'll ask the dumb question....What is "break-in oil" ?

 

"Once upon a time" (1950's-60's) we ran thin oil, 10W or so, for the first 500 mi in a new or newly rebuilt engine. In fact, my family's new 57 Chev came with "break in oil" and first dealer oil change was at 500 mi.

 

Joe Gibbs (Driven) is a good example very high in zinc protects all internal parts during the initial break in period especially flat tappet cams & lifters I've used it on a couple builds kind of pricey but so is a wiped out cam in a brand new engine

 

Okay....Got it...Thanks

I used Valvoline VR-1 high zinc racing oil to break-in my roller cammed ZZ4....I use it in my flat tappet 265 at every oil change as well.

 

You can change at 100 miles or you can just change it after the cam break in is over (flat tappet). Change the filter too.
This is all less critical with a roller cam and moly rings, but you should still change it early, long before a regular oil change interval.

 

any new engine will shed some metal no matter how well it's built on initial start up & run cycle the high zinc minimize the initial wear on everything definitely more critical with flat tappet cams than roller engines & zinc additives should be added to any oil not especially blended for flat tappet equipped engines at every oil change such as mentioned Valvoline vr1 racing oil

 

Back in the day we used 30W non detergent oil for break in to seat the rings.Used to buy it buy the case ( a case then was 24 cans ) and used a pint of STP oil treatment mixed with a pint of the same oil for assembly. Used it on every thing but the rings and soaked the lifters in the other pint of oil left over. Never had a problem with oil consumption or camshaft and lifter wear. I guess even the N/D oil was full of Zinc.

 

as I understand & I could be completely wrong zinc was removed from modern oils due to it causing contamination in catalytic converters plus most if not all modern engines now use roller type valve trains I'm curious if that's correct & if there is other reasons for zinc removal

 

I think you nailed the reason.

 

Break in oil for flat tappet cams is different than roller cams. It's also lighter viscosity oil for roller cams vs. flat tappet engines.

 

THE very best break in lube to me is still GM engine oil supplement (EOS). I have to be careful to find and buy the old formula that isn’t made anymore. I used to find some every once in a while at swap meets. I have many cans now, so I quit hunting, Don’t think I have enough time left to build and fire up that many new engines. LOL

 

Attached is a set of instructions for engine break in that came with my flat tappet GM 350 crate motor. The instructions state that mineral not synthetic oil be used for break in. I used Royal Purple break in oil, which is mineral/ dino oil.

 

Old formula GM EOS was a really good product but no longer made (EOS is still available but not the old formula). it turns up on ebay every once in a while but dear god when it does, you would think they were selling Roman gold pieces. Flat tappet cams, and high spring pressures are hard on a cam so a good break in oil I think is essential to having the best chance of breaking in a motor without wiping a cam lobe or two. Joe Gibbs-Driven sells a version, although I have never used it myself. I do use the Driven GL-4 gear oil in the muncie and it works well. Brad-Penn (now Penn Grade One) sells a pretty good version of break in oil. That one I have used with a couple of motors with flat tappet cams, spring pressures anywhere from 270 through 300 lbs open, and every motor I used it on broke in just fine and no issues. I ran the break in oil for 100 miles, changed it and ran the regular Brad-Penn 10-30 high zinc.

Truth be told, there are other brands that probably work fine, I just dont want to tempt fate given the success I have had with the Brad Penn.

 

It also depends on the cam specs. A cam with huge lobes needs the zinc at all times, A small stock type cam doesn’t need it much. I have a flat tappet in my old Crummy truck. 0ver 300k on it and all I run is off the shelf oil with zero additives from me. Any and all hotrod engines of mine get EOS added at oil change time though. At first-fire break in it goes without saying that the motor isn’t turned without EOS in it first.

 

Real popular with the Buick guys...

Pardon Our Interruption...

 

In the late sixties early seventies GM had major issues with camshafts having a lobe or several go flat along with valve guides wearing out & they had 5year 50,000 mile warranty so as a line tech I replaced many cams & lifters along with pulling heads to have valve guides replaced if there wasn't a can of GM EOS charged out on every repair order with either of those repairs warranty was denied great stuff at least the old formula was new Short & long blocks came with EOS well up into the late nineties anyway

 

Here is what I used in my 235. Probably ran it 200 miles. I had another issue, valve stem failed. On the restart it was changed to Amsoil Zrod 20w/50.

 

Big fan of Renegade racing oil and their break in oil.

 

Not trying to steal the thread but on a somewhat related topic . I bought a GM #366250 454 LS6 solid lifter crate engine many years ago for my 56 , I think It was the late 1990's right before the 502 came out , and am just getting ready to light It off for the first time . It came with oil In It . Anyone know If GM put break In oil In this crate engine back then by any chance ? If not , Is a good supplement such as EOS added to the oil sufficient or Is It necessary to add a full crankcase of break in oil ?

 

Main question i'd have would be sitting all this time would it have formed any moisture in the oil maybe not Just thinking if you don't drain the oil & refill with something like Joe Gibbs Driven or equivalent then i'd for sure add a zinc additive plus i'd use a priming tool to circulate oil before cranking & turn over several times by hand

 

The above in the pop-top can is the best stuff. Anything in the GM plastic bottle (newer formula) isn't that great for a flat tappet.

 

I drained the oil out years ago and have It In 2 plastic jugs because It came with a deep sump 8 or 9 qt. pan which I obviously could not run on my 56 . I was thinking about putting the original oil back In and adding a good supplement , and yes of course priming It good . So the question Is , Is It better to run ALL break In oil , or Is adding a good additive sufficient ? It has a pretty high lift mechanical cam and I don't want to hurt It . I used EOS many times working at a GM dealership also , to me It seemed very similar to STP .

 

Obviously the EOS and ZDDP type stuff you mix in. The other types you fill the crankcase with it just like normal.

 

I forgot to ask , If I get the Joe Gibbs Driven break In oil , which I may do , which weight would be best for a GM crate engine ? Thanks guys .

 

I'd guess the oil probably is still good if that's the case might have been even had it still been in the motor the oil pan is it the type that looked like it had a lower section welded on the reason I ask is way back when I ran a 55 B modified late sixties I used a factory L88 oil pan it fit perfectly although may not have on a lowered car back then everything was shove a set of 409 station wagon springs in the front & add leaves to the rear till is set level

 

I think i'd go with 10/30 if they have it I used 5/30 when I built my last two ls engines

 

never use synthetic oil