Flat tappet lifter failure

[Terry Cain]

Curious how many have had this problem regardless of reasoning in last 5 years or so.

[GTX JOHN]

My boy has had issues that have cost engines while
running the expensive billet stuff.

[Run to Rund]

Spring pressure and lifter diameter are factors as well. Stock lifters are good at 380 lb. open and .921" diameter. 500-550 lb. open are another story.

[Gmirza]

I lost one cam lobe, I noticed it after about 100 runs. I’m not sure when it went away. Most likely caused by lack of oiling at low rpm. From what I’ve been told the tool steel lifter, cast cam combination is only good for maybe 200 runs if you’re lucky. Go fast stuff can be a P.I.T.A.

[Paul Precht]

Originally Posted by Gmirza

I lost one cam lobe, I noticed it after about 100 runs. I’m not sure when it went away. Most likely caused by lack of oiling at low rpm. From what I’ve been told the tool steel lifter, cast cam combination is only good for maybe 200 runs if you’re lucky. Go fast stuff can a P.I.T.A.

Hi George, do you know what your spring pressures were open and closed.

[Gmirza]

Originally Posted by Paul Precht

Hi George, do you know what your spring pressures were open and closed.

Hi Paul,
I’m not sure. I didn’t check them.

[Demon340]

Originally Posted by Gmirza

I lost one cam lobe, I noticed it after about 100 runs. I’m not sure when it went away. Most likely caused by lack of oiling at low rpm. From what I’ve been told the tool steel lifter, cast cam combination is only good for maybe 200 runs if you’re lucky. Go fast stuff can a P.I.T.A.

Lost a Tool Steel lifter after 6 runs..

[Stan Weiss]

Originally Posted by Terry Cain

Curious how many have had this problem regardless of reasoning in last 5 years or so.

Terry,
Since it seems getting lifters is a problem. Is the cam still OK? If so have looked for someone who can resurface those lifters?


Stan

[JGrossijr]

It appears that some on this site may be in the wrong class or running the wrong combination. To those, please pick something that fits your personal agenda and leave the silent majority alone.
Thank you,
Jim Grossi

[Alan Roehrich]

I'm hearing the rule change is "out of the question", which is a great thing.


Was in the shop with a legend yesterday, he's raced as long as I have lived. All he said was "them boys will keep on and they'll be in Super Stock soon."


The lifter change is NOT a solution. It won't prevent failures. Roller lifters fail, too. And it is just as catastrophic. It would require an entirely new lobe design, you don't just stick roller lifters in on the cam you have. Flat tappets can actually accelerate FASTER at a certain point. But then the roller comes into its own. If you change to roller lifters, you need different springs, and different pushrods. The stud mount rocker cars will snap rocker studs like twigs. The cars allowed 0.875" and 0.904" lifters will have access to better lobe profiles, and have fewer roller lifter failures.The stud mount rocker cars will also rip the rocker stud bosses out of the heads. Current valve spring technology will allow the use of lobes that will extend the RPM range, by 1,000 RPM.


The introduction of roller lifters will simply begin series of escalations that will take 3-5 years to develop, and cost thousands upon thousands of dollars. It will alter the factoring drastically. If anyone ever lets that genie out of the bottle, the class will be wrecked for years.