Flat tappet lifter failure

[Rory McNeil]

I have been running Brad Penn/ Penngrade 1 high ZDDP oils on both my flat tappet, and hydraulic roller stuff, for many years, never had an issue. This oil is advertised as "the flat tappet oil" right on the bottle, and I have never felt the need to try to be a backyard chemist by trying to add any other "magic elixir " to it.

[340Cuda]

Originally Posted by Alan Roehrich

One person you might talk to is Lake Speed Jr. He works at Total Seal, he's a tribologist.
.

I agree and he is very good about quickly answering emails.

lake@totalseal.com

[Eman]

I know stockers must be running higher spring pressures and more exotic cam profiles then the average circle track or bracket car. I've never owned a roller cam, maybe someday. The last 2 I broke in I did use "break in" oil, in the past I used non detergent 30w or regular 30w with GM EOS additive. Break in is always high anxiety no matter what especially after all of the failures you hear about.
As far as oil goes I've used just about everything on my last bracket motor. I used regular Mobil with Lucas ZDDP additive, Valvoline VR-1, Lucas Hot Rod oil, Mobil 1 10w30 with Lucas additive, Mobil 1 15w-50 no additive and I've run it on AV gas, 110 and Methanol. Valve lash was always spot on. Howards solid flat with the laser hole on a Howards tight lash cam.

[Doug Hoven]

I'm sure it depends from combination to combination, as well as the "harshness" of the cam profile, but it seems like on .390/.410 small block Chevrolet stuff, once the duration @.050 gets into the 270s, cast cams and regular lifters don't seem to last very long. This mostly being down to the added spring pressure in order to control the more radical lobe. I've had good luck on multiple engines with solid lifters from Clay Smith Cams. I asked over the phone who manufactures them, and I got the response Howards/Johnson.

[L.Fite]

Yes, I was considering calling/emailing Lake...

I've seen all the oils mentioned above, but I assumed those are brands people would be using, I have used Castrol and Royal Purple personally, but that was long ago and always in a roller application.

As I am considering building a flat tappet motor in the future, I am quite curious about the current issues and how to avoid those problems.

Do these oil companies have specific oils formulated just for the flat tappet motors?
Or do I have to add additives, and then here we go with the amateur chemist act.

[Eman]

Last 2 solid flat tappet cams I broke in were in the 250-260 @ .050 range. Once broken in I question the special formula oils and additives. I like oil I can buy at a reasonable price easily which is why I went to the Mobil 1 15w-50 which is a higher ZDDP package and didn't require any additives.

[goinbroke2]

My cam is .398 and 250@.050 Never had an issue breaking in dozens of other cams but.. should I put light break in springs on then switch once its broke in??

I've been using GM EOS for 40 years and have never had a cam lose a lobe, but again, I've never run the spring pressures and lobe profiles like this either.

[Chipper Chapman]

Originally Posted by goinbroke2

My cam is .398 and 250@.050 Never had an issue breaking in dozens of other cams but.. should I put light break in springs on then switch once its broke in??

I've been using GM EOS for 40 years and have never had a cam lose a lobe, but again, I've never run the spring pressures and lobe profiles like this either.

100% start with a lighter spring

[Alan Roehrich]

Originally Posted by goinbroke2

My cam is .398 and 250@.050 Never had an issue breaking in dozens of other cams but.. should I put light break in springs on then switch once its broke in??

I've been using GM EOS for 40 years and have never had a cam lose a lobe, but again, I've never run the spring pressures and lobe profiles like this either.

It is ALWAYS a safer bet to run lighter springs, and or low ratio break in rockers. I bought a set of 1.3:1 rocker arms just to break in the cam on one engine, rather than disturb a set of high priced heads that didn't belong to me. I know several builders who keep a set of Shubeck lifters set aside, and used them to burnish every new camshaft, then swapped to break in springs or rockers, and put in the new lifters that were to stay in the engine.


I use moly disulfide paste on the lifters and camshaft, then I use a mixture of Brad Penn oil and one of the extreme pressure red assembly lubes for assembly. Then I use Brad Penn or Lucas break in oil for the break in on the dyno. My engines are all pre lubed, the carburetor is primed, and the ignition spark timed, so that they do not crank for an extended period of time. They start, go to 2500 RPM, get the timing set, and get run between 2500 and 3500 for a full half hour, without stopping unless there's some sort of emergency, like a massive leak, or excessive oil or water temperature. Then they get the oil drained, the filter swapped (I prefill my filters) and any change to the valvetrain, springs, rockers, or both. Then they get 15-30 minutes more run in with fresh break in oil. We check lash, etc, and then start pulls.

[Mark Yacavone]

Originally Posted by goinbroke2

My cam is .398 and 250@.050 Never had an issue breaking in dozens of other cams but.. should I put light break in springs on then switch once its broke in??

I've been using GM EOS for 40 years and have never had a cam lose a lobe, but again, I've never run the spring pressures and lobe profiles like this either.

How much seat pressure do you think you need with those little valves and a 2 bbl?