Flat tappet lifter failure

[Darcy Clarke]

I have used Renegade race oil 5/20 and 10/30 it only comes in semi-synthetic, I have used it for over 10 years with great results.

Darcy Clarke
6254
A/SA SS/EA

[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.

[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?

[goinbroke2]

Originally Posted by Mark Yacavone

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

Both pounds...LOL!

[Terry Cain]