I have been running a flat tappet 590 in my 416 since it was built. The first had about 230 runs on it when I lost a lobe on it. Wasn't the cams fault a mechanical issue. When I broke in the first one the inner springs were removed. Freshened the motor and installed another one. This time the person who freshen it didn't want to remove the inner springs to break it in. This one lasted about 19 runs and # 7 intake lobe went flat. I think it was because the inner springs should have been removed to break it in. My friend who freshened it believes it is a lubrication problem. Because my car sits so long between outings. I get it out maybe 4-5 a year.

Getting ready to put a new cam in it again. I have already purchased another flat tappet(an UD cam). Do you think lubrication is the issue or was breakin procedure the problem or both? Jim

Inner spring should b removed for break in. Let's the lifter spin easier for break in. Use good oil with zinc or use an additive.

Had a nos 528 mopar cam from the late 80s early 90s, broke it in with both springs and that motor was fine for 5 years. Switched to a .557 cam that was made around the same time. Broke in with both springs never lost a lobe.

Changed to a 590 cam last year that I got from jegs, same as always break in oil, both springs, fired right up with good oil pressure but lost a lobe very shortly after.
I have heard from a few sources some of the cam cores now days are made of junk metal, or maybe my luck ran out!

Put a felt tip mark on the exposed lip of each lifter. Turn the engine over. Keep swapping lifters around until they all rotate. A borrowed tip that seems to work.

How much pressure and RPM do you run when in race mode?

Are you running lifters with the EDM hole in the face for extra oiling? If not I'd switch to EDM lifters.

I switched to nitrided cams and EDM lifters and didn't have any issues after that. I also used the lifters with the ceramic puck for a while. Expensive but worked well.

Often overlooked are the lifter bores themselves--first thing many do when a lobe goes flat is yank that now mushroomed lifter through the bore pulling it out the top--now you have a scratched--grooved--hurt lifter bore so you are doomed to repeat the trouble--
The BEST answer is a lifter bore ball- sizing broach- sold by Goodson --You hammer it through lifter bores and then slide hammer it back the other direction--sizes, smooths, and straightens lifter bores This is CRITICAL after an engine has been shoot peened as in AMPRO shot blasted for cleaning and we use it on every build--this goes a long way toward curing the issue--we have been using Lucas break in oil at over 3000 PPM ZDDP etc and it has been wonderful--cheaper than all the others as well
Then...all the normal inners removed etc

I'm running .620 lift and a pretty fast lobe...similar to a Comp MM series and a double spring with 165 on the seat and IIRC 450 open when they were new.

I don't use anything special and I've never removed the inner spring. I use a QUALITY oil and keep the idle at 1k or a bit above.

Haven't had a flat lobe yet.

The only issue I've had was about 2004 or so and the lifters we were getting were junk. Lost 5-6 cams until I caught the issue.

At 19 runs its not a break in issue. If you had issues on start up, they show up right away.

I used Howard's direct lube lifters in my last 2 builds. One being a SB and the other a BB. Both engines have SFT Comp cams and have had no problems whatsoever. Lobes and lifters look great in both engines after 50+ runs. The Edm lifters leave a nice stripe of oil on the lobes just cranking the engine over. I run Valvoline VR1 in both engines fwiw.

180 on the seat and 380 open. Shift @ 7000. No on EDM lifters.

Your on the edge of pressures, on both seat and opened, that I would not increase
The thing to keep in mind is that you will usually loose some lift due to valve train deflection on the full lift when opened all the way

Some comments and additions to some already good info.

1. Absolutely make sure lifters are rotating before the engine is fired. If they don't it is almost certain death to a cam.

2. The added expense for edm lifters when running solids is good insurance.

3. Honing the lifter bores is a good idea, but be careful about using a ball hone. I had a Hemi in the shop early this year that the owner had honed with a ball hone. Several lifters would not rotate. The balls had raised a razor sharp edge in the bores on the oil galley. It was hard to detect, but re-honing got the lifters to rotate.

4. If you feel real lucky, break the cam in with full spring pressure. The worst that can happen is that you have to tear the engine down to clean the mess. Sort of like saving a few minutes by not degreeing the cam.

I never used to take the inner springs out on the mild cams I ran like the MP .484 and .557 cams and never wiped a lobe. But on the eng in my 63 now I had a custom grind solid flat tappet from Dwayne Porter and it runs a little more spring pressure then I had run before. So Dwayne left the inner springs off my heads I bought from him and I used the EDM lifters that he recommended. He also nitrided the cam. I use Valvoline VR1 racing oil and a bottle of zinc additive. Cam broke in fine and has been in the car since 2011 and still going strong. I waited about a week and then installed the inner springs. To me its a good idea to remove the inner springs as it wont hurt a thing and may just help the cam break in better. Good luck with your new cam. Ron

To me it boils down to this.......

If you're running an aggressive flat tappet cam that requires a dual spring to maintain proper control of the valvetrain at high rpm's......... And you don't remove the inner spring for beak in....... And you have a problem with chopping a lobe prematurely......... It's just "shame on you" IMO.

This is in addition to making sure you are using the best break in lubes/oils, and have insured there is adequate lifter rotation prior to engine start up.

I agree.

The most important thing is getting the engine fired. Cranking on them is death.
Then lifter rotation.
Then oil.

I'm getting ready to start another SFT engine in two weeks. 145 on the seat, 400 over the nose. I'm not pulling the inners out.


I'm now convinced that I've said this publically I'm going to have this one go flat.
I've got a known ignition and known carb.
But I'm sure I'll get burned now just so fate can say it's made me eat my words.

I'm not a guru, I'm pretty much nobody and kinda like it that way.

What about lifter crown?

what do you do if the lobe taper seems right but lifter crown doesn't?

Who even takes a moment to try to look at lifter crown?

Waste of time? I've had a guru here pretty much say so, in the past.
I disagree.

I have had the pleasure(?) of inspecting many, many lifters and cams on a pretty regular basis. Some new, some failed, some close to failure but not quite. During the time I was in that activity, I could not find any cams I honestly thought were made improperly. I sent many off to be tested...engineers a whole lot smarter than me, with diplomas and everthang (deliberately misspelled) ran multiple cams through the gamut of tests and there was never an issue found.

But I found many lifters that had either no crown at all, or barely enough to make the lifter rotate. At least a couple times a week, I'd find some that were flat or nearly so.

Not saying it's a 99 percentile killer or anything like that, but maybe it is worth a closer look than in the past.

On the last flat tappet hydraulic engine I did for myself, I went through 2 sets of lifters to find one set that I personally liked the looks of. And once I selected them, I didn't just use them! I took all of them apart, cleaned and oiled each one internally and reassembled. Waste of time, right? Lots of gray metal on the paper towels I used. Metal shavings visible in the solvent container. Good thing I'm not a high volume professional, I'd go broke doing that kind of thing.

I agree with Zippy A simple way to check for crown is set one lifter face against side of another lifter--hold to the light and Bingo--Now I have been in shops that made fixtures to check exact amount of crown but that was in bad old days of crappy oil etc An easy way to check lobe taper is check cam up in lathe and just run dial indicator across lobe--works like a dream
I also take lifters apart if it is a high $$ critical build--I can't tell you how many have two metering discs--no metering disc, jelled up rust preventive--are full of wd40 so they are already pumped up etc Last week I had customer bring in s set of Cranes from the 70's in sealed box--Great I thought--parkerized faces--USA quality--I always do quick check by just depressing plungers with a pushrod etc and one lifter was almost solid--took it apart--two thick metering disc in bottom of lifter and none where it was supposed to be so.......run solids baby!
I also have to say that the SBI lifters have been great and the Johnsons have been trouble all year long --I have seen four different engines have issues with them in one shop since Jan--not good and looks like the cheapo Summit cams come with SBI so that is a positive as that 6401 cam is a good piece for mild street
I hate honing lifter bores the broach works like a dream on plain blocks
and...let's face it no matter what all you do one fails every now and then just because

I was taught that the lifter lobes on flat tappet type cams where ground with a tapered to make the lifter rotate, not so?

Yes they are that way--it is not much but usually like .002 range? Different makers do it their way but the taper on the lobe and the crown both work together to promote rotation
You look through lifter bores at a Ford cam and the lobes are not centered on the lifters --another way to go even further on same idea

Throw a mic on a new cam and you will find out real quick.