Failure: COMP Cams Hydraulic Roller Lifters

Less than a year after install in my 1993 Mustang Cobra I had a catastrophic failure of a roller lifter. While driving down the freeway I heard the noise, drove home 3 miles and parked it in the garage. Unfortunately didn't have time to tear down the engine to find out why I lost the number 2 cylinder right away. Here is what happens when the roller seizes on the roller axle then destroys the retainer and seizes in the bore. The camshaft knocked the roller off the lifter then forces it up through the oil galley creating a quarter size hole. Here is the video of removing the lower intake and finding the hole.

[@jonramsden7622]

Oceannavagator has a point. You are using 1.7+ rockers, so you have a LOT of valve travel. Are you using very high rate valve springs too?? Check they will handle the travel from your cam lift TIMES your rocker ratio without bottoming out. A few years ago, I rebuilt my Harley (Evo 1200) into a straight line screamer. High compression, radical cam, souped up Super E, free flow exhaust, fully ported and polished heads. I checked the stock spring pressure, and that seemed wimpy (although it had worked well for 15 years). So I looked into heavier springs, as I put a much more aggressive cam set in it. If the stock valve spring seat pressure is 150 pounds, the performance springs are 200, then the super springs at 225-250 should be great. Right?? nope. After about 150 miles one lifter self destructed under the load, destroying the brand new cam set, not to mention all the little steel particles the ended up down in the crankcase AND transmission. It had high performance pushrods, and 3 of them were bent. No valve to piston contact either. Guys at the Harley shop said they'd seen that more times than they could count. Lesson?? for a streetable engine, only use just enough spring pressure to get the job done, and no more. If you are running the strip, spinning 10,000 rpm and doing a teardown every 6 runs, then use heavy springs. Otherwise, they cause way more trouble than they're worth.

[@jimburton4946]

Lifters were part of the kit and valve train was adjusted to about .5 past zero lash depending on the cylinder per Comp Cams. There was about another .75" of clearance between the valve and piston. Just a simple and costly failure unfortunately.

[@ThunderHead289]

? those don't look like comp lifters?

[@oceannavagator]

You touched the piston with the valve dude. Check those clearances!

[@Diondo26]

so, that was a comp cam lifter?? bad bad!! friend uses comp cam stuff in his Chevy and had a bad lifter too!!

[@lop8828]

Seized on clearance how surprising

[@Levisnteeshirt1]

how much pre load were you using ? should have been 0 ,,

[@Al5wi]

Very sad