Flat tappet cam; what oil?

I recently got my first vehicle in a long time that has a flat tappet camshaft. I've seen that most oils these days, even diesel oils, have changed their formulation in ways that (people say) can harm my cam and lifters. Is this true? If so, what oil do you use or recommend to mitigate this problem?

I use Brad Penn racing oil in my TR6.

We have all heard war stories about this, but I wonder how much of it is true.  

Right now I am using Valvoline VR1 20W-50 racing oil, in my Spitfire as its about the only thing you can find in a store.  There are several oils that you can mail order that are the real deal (Gibb's and Brad Penn (now with a new name)).  I've read that using a ZDDP additive doesn't really help.      

The pisser is Castrol makes a Classic car oil, but they do not import it to the US.           

In reply to snailmont5oh :

What is needed is ZDDP  ( zink ——potassium). It plugs up catalytic converters so modern cars can’t use it.   You can either buy the ZDDP supplement or buy oils still formulated for older ( pre1975) cars.   

In reply to spitfirebill :

MG’s  and older Chevies definitely suffer from lifter wear although most overhead cam engines don’t.  Personal experience.  

I think what both engines have is pushrods.  Shove a heavy lifter and push rod up have it push a rocker arm and the rocker arm will slide across the valve stem. All that sliding is what kills the lifters and valve stems. 

In reply to JoeTR6 :

You might get away with it for a while. I don’t know how that oil is formulated but the cool thing is the assembly lube usually is loaded with ZDDP .  That and some racing oils still retain the ZDDP in their formulation.  

Im guessing here but if the can says suitable for all cars they’ve eliminated the ZDDP  but if it says something about off road use only they may not have. 

In reply to frenchyd :

From the product description.

"Contains strong detergent, dispersant and ZDDP anti-wear additives to help protect critical engine parts"

It has the right stuff in it.  For now, until they reformulate it.

I had an old Ford van that had a flat tappet cam.  The problem with lobe wear appears mostly in engines that have high cam lift which results in high valve spring pressures and high load on the cam lobes.  I have read that on cams that have many miles on them, (I.E. well broken in) in stock engines you won't see much wear if at all. 

It's usually the first start on a new flat tappet cam and the break-in procedure that determines if you have a failure or not.  I may have to deal with this if I decided to rebuild an old Ford 2.8L V6 or not and install a "hotter" cam at that time. 

I always read that the ZDDP was only important for engine break-in, and that you could run the conventional stuff afterwards. Am I wrong?

I use valvoline VR1. Don't have much miles with it but a lot of other air cooled VW guys (all flat tappet) run it and are happy with it. I am currently rebuilding a VW motor that had 6 pitted (4 heavily pitted) lifters and happened to be running standard low-zinc off the shelf oil, so I won't touch anything that isn't high ZDDP.

The Mobil 1 V-Twin series, like 20W50, sold for bikes has the magic zinc stuff in it.  Not cheap, but then neither are cams or tappets.

In reply to Tony Sestito :

What kind of engine? Does it have pushrods and rocker arms? If so modern off the shelf oils will quickly ruin it.  It doesn’t matter with roller lifters because the cam is what gets eaten up if it has regular lifters and no ZDDP 

overhead cams get a break because spring pressures are a lot easier.  

I ran Lucas Hot Rod oil in my high-compression lumpy cam '77 Silverado, but I noticed the engine sounding different after 2000kms.  It made me nervous.

I switched to Shell Rotella Diesel 15W40 plus a thingie of ZDDP break-in additive every oil change.

I'm not brave enough to try regular oil just yet.

No lobes have gone flat, we're on four years of daily driving so far.  Heavy valve springs, too.

Dr. Hess said:

The Mobil 1 V-Twin series, like 20W50, sold for bikes has the magic zinc stuff in it.  Not cheap, but then neither are cams or tappets.

I noticed that one day while perusing the oils. But I was wondering if it had stuff you would not want in a car if the oil is formulated for clutches.        

This sorta thing is my game since I build a lot of old-school engines.

When it comes to flat tappet cams and lifters, they wear together.  The cam and base of the lifters are both surface hardened, but not very deep.  They start out with a specific texture and as they break in they wear each other to a new, broken-in texture.  This is why you can't put new lifters on an old cam or vice versa.  Think of it like this.  Let's say you take two pieces of identical emery cloth and start rubbing them together.  They would eventually knock the majority of the abrasive off and you can rub them together for a very long time once they've established even wear with each other.  Now switch out one of the pieces of emery cloth for a brand new one.  It will shred the worn-in one very quickly.

The lobes of the cam (and the lifters) are only hardened on the surface, so you can also picture them like a hard-boiled egg.  Once you break through the shell, the stuff underneath is soft.

ZDDP is preferred for break in.  The Zinc and Phosphorus compounds are anti-wear agents and the way they work is to increase the film strength of the oil so more stays in between the two components during valve actuation.  Very important for break-in, not very critical once its broken in.  If you have a flat-tappet engine that is already broken in, losing ZDDP won't really cause any headaches unless you were really close to wiping a cam before the switch.  In that case, ZDDP would have only given you a few more months anyway.

The loss of ZDDP in oil hasn't shown to increase wear appreciably in direct contact engine parts.  Suffice it to say that other advances in lube technology have all but closed the gap left by the loss of ZDDP.

The other thing of note is that with the obsolescence of flat-tappet systems, most lifter and cam manufacturers no longer make quality parts.  As of a few years ago, I couldn't find a single lifter manufactured anywhere but China.  Not that they couldn't make quality stuff, but Chinese metallurgy is still not up to par with what it needs to be, especially when many Chinese companies are still in the business of making things as cheaply as possible.

So, if you're breaking in a new cam/lifters, I strongly suggest using an additive for the first few thousand.  If it's already broken in, use your favorite brand of plain old oil and don't fret it.

In reply to spitfirebill :

The bikes that oil go in do not use that type of oil in the clutches, not that it matters.  People run any oil at all in Harley clutches, from gear oil to motor oil.  I use synthetic ATF.

A lot of Esprit people are using that M1 V-Twin oil in their turbocharged 910 motors.

In reply to Curtis :

I’m sorry to disagree with you Curtis. However Even older engines with well broken in cams still need help or will wipe out their lifters.  I have more experience with Chevy than Ford but my Ford buddies tell me it’s still true.  Maybe they dry out in storage or infrequent use puts added stress but they are still replacing cams and lifters. 

Perfectly fine to disagree and I respect it.  I'm just basing my input on dozens of teardowns of flat-tappet engines that showed no significant wear using non-ZDDP oil, and two of my own engines (one of which has run for the last 120k on non-ZDDP) with 200k on the clock and no issues.  I had a 62 Caddy that ran on nothing but no-name mineral oil and according to the previous owner it the odometer had rolled over at least 5 times through his and his dad's ownership of it.  Lifters looked quite nice when we tore it down.  (can't say the same for the piston with the hole in it after it dropped a valve)   There may be specific evidence out there to refute this, but I've only found internet lore and fearful conjecture.  That, plus my experience with it makes me recommend not worrying about it.  YMMV.

I will agree about the infrequent use part.  That is death to a flat tappet.  If its dry enough, one hit of the starter and you've scratched them and its only a matter of time until they're iron dust.

I was talking about this with a buddy of mine who is a chemical engineer. He expressed the opinion that modern synthetic oils have high enough film strength that you no longer need significant levels of ZDDP (or other anti-wear additives). Purely one person's opinion, of course, but it kind of made sense to me.

Having said that, I still use Brad Penn PG-1.

In reply to LanEvo :

 Please don’t tell my friend that who is looking for a new camshaft for his MGTF 1500.    He’s put a little over 11,000 miles on it since last replacing it. After break in he used Mobil 1 racing oil exclusively. 

But I do agree that modern oils do wonders on modern engines. Even older engines that have been updated like the old Chevy small block 

Things I know. 

I wiped one once, started to lose an exhaust lobe in a well broken in, smog era, stock cam, OHC (bucket over valve) engine with a bucket diameter that makes most of the pushrod V8 lifters look tiny, with wide lobes to match, with a crankcase full of M1 15w50 (advertised 1200 ppm phosphorous, 1300 ppm zinc), overkill on overkill and it still ate a lobe. 

Engine oil the 1960s only had about 800ppm phosphorous, without any of the fancier antiwear additives you find in modern regular oil with similar ZDDP content (800 max for the most part, now including the dual rated diesel oils) The higher ZDDP content that is often  referenced came later during the smog era for reasons unrelated to wear (it was cheap and helped prevent sludge formation in the hotter running engines). 800ppm was decided on in the 50s, supposedly it maxed out whatever test device they were using at the time and was deemed good enough. It should also be noted that too much is bad, there's a point where increasing ZDDP increases wear. 

Proper heat treat of the cam lobe and lifter face is very important, there were some runs of American V8s  in the 70s (I want to say 305 Chevy was the big one) with tiny cams and weak springs that had cam problems, running that high zinc 1970s oil, due to heat treat issues. I suspect my Fiat built by communists also had that problem. I suspect (and I'm not the only one) that cheap imported lifters coming onto the market around the same time as the API SM spec being phased in was/is the real issue, ever notice how all the wiped a new cam horror stories only kill one or two lobes? By the time a couple are badly eaten up you would think a lubrication failure would show on all lobes. 

For better performance, ramps on modern performance grinds are faster than the old performance grinds, check out the difference between advertised and .050 duration on any of the old factory hipo cams and compare to a snotty one from Comp or whoever. This means the lifter gets accelerated a lot faster with a modern grind. That probably doesn't help matters, reduces tolerance for overlooked problems, lifters not spinning, improper break in procedure, etc. 

At least until recently (haven't looked lately) GM would sell you some fairly hot, assembled and unfired, hydraulic flat tappet SBC crate engines, with a warranty. The instructions that came with them just said "use a quality 10w30 oil" well into the current API SN oil era, no additives (Speaking of which, I've seen any backed by actual science with published methodology and data) no animal sacrifices, just put oil in it, start it and immediately bring it up to 2000 rpm or whatever for half an hour. 

As for stock low output already broken in stuff, there are plenty of light trucks/SUVs from the late 80s/early 90s with flat tappet cams still running around, plenty of them probably live on a diet of whatever cheap 5w30 comes out of the big barrel at the oil change place. 

TL;DR I think it's mostly internet lore, manufacturing defects, pushing the limits of the technology because people want roller cam performance without spending roller money, and installation/break in errors. There's no solid evidence that points at the oil being the problem, todays regular old oil (let alone the heavy duty diesel spec oils) should be quite a bit stouter than anything people were running in the heyday of the old pushrod V8s. If it isn't worn out any brand name Xw30 should do great, especially in a stock low performance engine. I prefer synthetics but that's a whole different can of half true worms. If you really want a high zin/phos oil Rotella T4 (which comes in a 10w30, I think Walmart stocks it) still has the "good stuff" at the old levels, as it is no longer rated for service in gas engines and not held to the new limit. 

I use Shell Rotella T 5w40 Synthetic in my 78 Z28 that is  mostly strip vs. street driven. Flat tappet cam. I've used Shell Rotella mineral oil in the past with success in other motors also.

I've been a victim of the "wiped cam" and lifters from when oil was changing out of the additives.

You can buy 4qt containers of Shell at Walmart. 

Do you use any additive with the Rotella?  How high are your spring pressures?

I am not yet brave enough to lose the additive.

I have wiped two cam lobes in my life and both were due to sitting for 20+ years with no simple way of lubing the cam before starting it.  Spinning the oil pump doesn't do the trick usually since cams are primarily lubed by crank splash.  Fortunately they were both engines that I didn't "care" about or was planning on rebuilding anyway

In reply to BrokenYugo :

Very good point about modern camshafts and their ramp speeds.

Anecdotal data point, so not worth much:

I run plain 10W30, straight out of the bottle, in my Slant Six.  No problems at the solid flat tappet lifters and cam. Note that the 225 is a low-stress engine with a reputation for durability.  I worry a lot more about the oil pump gear than I do about the lifters.

If I did a cam/lifter change, I would probably add one of the break-in ZDDP's, or use oil designated for break-in, for the first oil change or two.  I'd follow the cam company's instructions if they were specific.  Then I'd probably go back to plain oil for general service.