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WFO
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84 chevy driver said:
is it common for lifters in a sbc to go bad after only 600 or so miles ?
It is "common" if:
  • A new set of lifters are installed onto an old camshaft.
  • A new cam is installed and old lifters are used on it.
  • A new cam and lifters are installed, and they are not broken in properly.
  • The valve train has broken components.
  • The valves are improperly adjusted.
  • There is a lack of lubrication.
  • There are defective parts.
  • Etc.
Care to elaborate? :rolleyes:
 

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Discussion Starter · #5 ·
ok here is the deal several years ago i bought this engine kit from enginekits.com finaly got around to using it put this motor together got it running every thing seemed fine went through proper fireup procedures cam break in practices and all drove aprox. 600 miles coming home from work pulled in drive noticed rockers clatering now have to figure out why.. lifters are ssi i believe cam is erson stock pushrods stock rockers z28 valve springs any guesses?
 

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Pop the valve covers off and check to see what rockers (if any) are loose. Check those that are. Some possibilities are that you have a cam with some flat lobes, bad lifters, bent pushrods, brocken rockers, rocker nuts that backed off or even studs pulling out of the head. Hard to know until you inspect everything. How's the oil pressure??
 

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WFO
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84 chevy driver said:
any guesses?
The recent (and not-so-recent) changes in the oil formulation has made the failure rate of flat tappet cams and lifters skyrocket. The new government mandated formulations call for much less zinc-based (and other, I've read) enhancements to be allowed to be added to the oil, enhancements that were previously there primarily to protect flat tappet-equipped engines.

Now that the engines coming from Detroit and elsewhere are roller cam, roller rocker fulcrum-equipped, and due to the damage that the oil additives were doing to the catalytic systems, these additives are now below what is needed for the protection of flat tappet engines- with the exceptions of some diesel and racing oil formulations.

You can search this site and/or google for more on the subject.

This is my best guess at what has happened to you, especially if you didn't add an additional oil supplement like ZDDP to the oil before initial start-up.

And you are not alone. :mad:
 

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WFO
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84 chevy driver said:
no i was trying to get an idea before tearing into it kinda disgusted ya know
Why anyone would choose to reuse a $10.00 set of rocker nuts is beyond me, but if that's what you did- go buy a fresh set, relash the valves, and hope no damage has been done to the cam/lifters by the mistake.

Good luck!!
 

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One way to tell if you have a flat lobe on the cam is to crank the engine with the valve covers off (pull the power to the coil....I've had that brainfart...lol) and watch all of the rockers. If you have a flat lobe or one going that way the rocker won't open the valve as far as the others. Just a suggestion.
 

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It`s not uncommon for a new cam and lifters to need readjusted, at least it never was for me. I can recall many times after breaking in a engine I had to go back and readjust the rockers, it was likely due to the new valves and valvetrain had not been seasoned in but they usually were set by the first 50 miles. Hopefully this maybe the case you have. But I would still pop the valve covers with it at idle and check to make sure the cam hasn`t got flat.
 
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