I think i've done it this time.On the highway the other day,some guy blew by me doing about 100 in a fairly new chev halfton.Normally that doesn't bother me ,but this guy was especially insolent.Long story short,i dusted him ,but he wasn't easy.Had to work the old girl pretty hard.When i let off her i could hear a slight knocking at around 2000 rpms.Oil pressure was still good,temp was good.It kind of sounded like a rocker was loose or something which made sense because i just did the whole top end this winter.Today i reset the valve lash ,did find the #8 cylinder valves were kind of loose,so i thought that i might have gotten lucky.Went for a road test and the noise is still there.What do you guys think?Rod bearing?Crank bearing would drop oil pressure right?The noise seems worse when i let off the gas if that helps.Does gm sell short blocks? ha!

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86'Camaro Berlinetta SC,former 2.8,now 327 cid with 350 tpi heads(pocket ported)summit k1102 cam,305 H.O. aluminum intake,edelbrock 1405 carb,recurved HEI with accel adjustable vac advance can,rebuilt 700r with shift kit,B&M mega shifter,grant steering wheel,t-tops,american racing wheels,louvers....now if i had fresh paint,subframe conn.,cowl induction hood..sigh..

 

does it still sound like you've got a loose lifter?
we just went throught this with my buddies 81 malibu wagon(don't laugh it's a 10 second wagon)we adjusted the valves three times before we figured out that wasn't it!we pulled off the tunnel ram to check out the lifters
the #6 exhaust lifter was stuck.it wasn't traveling the full leagnth of the lifter bore.we had to force the lifter out with a pair of channle locks

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1991 banditt2 #130 of 600
Project 350 TPI Banditt II
http://www.street-dawg-racing.cityslide.com
http://discussion-board.com/GreaterC...dyAssociation/
http://www.cincyspeed.com/

 

Momma take these guns from me, cough, cough,
Well it does sound like it could be a rod bearing but if the oil pressure doesent drop than most likely its valve train related. If you adjutsted the rokers and its still there is could be a bad lifter. One of the lifters could have gotten fryed and could be bleeding to much oil causing a rocker to get loose.
Just a thought.
SSC

 

This is kind of encouraging.I didn't suspect the lifters because they were new,but i guess i could have gotten a bad one.I didn't spend a fortune on them,they were bought at V.I.P autoparts for around 30 or 40 bucks.The brand name was "wolverine" and they were the type that look like there's a paperclip at the top.I run 350 TPI heads and i think the valve springs are stiffer,so maybe the higher lift cam (420,442)plus the stiff springs ,might have killed it.Do you guys think thats why the #8 rocker was so loose?(lifter not pumping up?)This engine has never made a sound until now and i am really not hard on it,despite the half ton story.Could the high revs have finished the lifter off?If it was bottom end,would i see a oil pressure drop for sure?I still get 50-60 psi when cold.I want to thank you guys for the help and i invite anyone else to jump in with suggestions.A bad lifter sounds a lot better than rod bearing failure.

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86'Camaro Berlinetta SC,former 2.8,now 327 cid with 350 tpi heads(pocket ported)summit k1102 cam,305 H.O. aluminum intake,edelbrock 1405 carb,recurved HEI with accel adjustable vac advance can,rebuilt 700r with shift kit,B&M mega shifter,grant steering wheel,t-tops,american racing wheels,louvers....now if i had fresh paint,subframe conn.,cowl induction hood..sigh..

 

Have to face it ,this is more than a lifter.This thing is shot guys.Took it out on the street and it's much worse than before.It's now a loud rapping noise,can't go into 2'nd without major noise.It's hard to say goodbye.Guess i'll start saving for a good wrench crate motor.