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rebuilt 350 chevy valve adjust

Discussion in 'The Hokey Ass Message Board' started by jimcaf, Feb 21, 2012.

  1. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

    I got my 350 running,and ran it the 20 minutes at 2000rpm for the cam breakin,halfway through the break in I started hearing a slight lifter tick so I let it run the whole 20 minutes and then let it idle down and pulled off the valve covers one side at a time and readjusted all of them at idle.When I got done it sounded and idled great.Now after about 2 hours of running Im hearing lifter noise,not real loud but its there and on I bet 3 or four of them.Iv never had to readjust lifters on a rebuild with hydraulics lifters .Im hoping its not the dreaded " flat cam",I dont think it is only because its got a very smooth idle. Can anyone shed some light on this....thanks ahead for any input,,,jim ,,,
    (by the way its a summit 1102 cam and lifters)
  2. 1971BB427
    Joined: Mar 6, 2010
    Posts: 5,482

    from Oregon

    Have you tried adjusting them with the engine off? I never adjust SBC rockers while running. Too messy and unreliable. Get the engine on #1 TDC and adjust all closed valves to zero lash, then turn 90 degrees and adjust the next set, and keep going until you get them all done.
    If they continue to loosen up then I'd question the rocker studs? (push in?) or the lifters.
  3. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

    I originally did them on the stand,what I did was marked the balancer in quarters and I set it on 1 and started there to zero lash then 1/2 turn then spun then engine a quarter of a turn and did the next in the firing order ect.
  4. 48 Chubby
    Joined: Apr 29, 2008
    Posts: 1,016

    48 Chubby
    Member Emeritus

    It is starting to tick way too soon to not have a problem.
    Could be...........

    Poor quality rockers, balls, or loose adjuster nuts.

    cheap push rods some times "collapse" when the ends push up into the shaft-I have not seen this in years.

    pressed in rocker studs lifting out of the socket.

    the valve seats were "inserted" and not seated properly. (not a usual Chevy priblem)

    the cam is fading fast.

    You don't see any of these problems much any more, but they are all still possibles. A bad lifter or two is also posible but this don't sound like a lifter to me.
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  5. hustler1984
    Joined: Sep 23, 2011
    Posts: 57

    from lindsay ca

    Have you checked oil pressure?? And what oil did you use for break in.
  6. This is a long shot but ... (not knowing anything about your rebuild), make sure the rocker studs themselves aren't working their way out of the head. If the rocker studs are factory press-in type, they can come out with high rpm or tons of valve spring pressure (run a straight edge across the tops of all of the studs on one side of the engine at a time ... the straight edge should touch all of the studs. If a couple are higher than the others, they just might be coming out of the head).

    One other thought ... and a real long shot here too ... mechanical fuel pumps can sound just like valve train issues (although the sound from a faulty pump would not change from a valve adjustment).

    One other thought, are the noisy rockers only on one side of the engine? If so, you could have an oiling issue (although I would assume you would notice dry rockers when you were doing your adjustments while running the engine).

    As another poster has said, try adjusting them with the engine turned off (this is the ONLY way I will adjust them).

    If you aren't sinking the pushrod (and lifter plunger) deep enough, the just might start to clack as the engine heats up and the clearances change slightly.

    Did you pre-oil the engine before firing it? Did you lube the cam before installation? Did you add the "cam break-in lube" to the oil before starting the engine?

    Are you using flat tappets or rollers? Are the lifters new? If the lifters are used, did they go back on the lobes they came off of?
  7. This is the method I use to set SBC hydraulic rockers cold/engine NOT running.

    1 ------------------------ 6
    8 ------------------------ 5
    4 ------------------------ 7
    3 ------------------------ 2
    6 ------------------------ 1
    5 ------------------------ 8
    7 ------------------------ 4
    2 ------------------------ 3

    Adjust both intake and ex rockers on #1 cyl when the intake and exhaust on #6 is just rocking .... do the rest using this chart as a guide (eg. adjust 8 when 5 is rocking etc)

    Once you have "taken up the slack" on each rocker (I use the "spin the pushrod" as my guide) go 1/2 turn more.
  8. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

    I have very good oil pressure and lots of flow under the valve covers,the cam,lifters and springs are new,the engine is a 92 truck 350 with center bolt valve covers, I used the specified assembly and cam lube and delo oil for the breakin.The adjusting nuts,rockers,balls and pushrods are the original.I guess in the AM il get a look at the studs with a straight edge and try to readjust if it passes another visual,,,,,,
    thanks very much for the tips,,,jim
  9. I just googled your cam, seems very mild so I am going to assume stock valve spring pressure (and therefore the poss of the studs coming out is pretty slim).

    I'm thinking you probably just need a good valve/rocker adjustment (but verify that it isn't your mechanical fuel pump too because they can sound EXACTLY like a noisy lifter).
  10. fiddy
    Joined: Sep 24, 2009
    Posts: 163


    ....i've heard delo does not have the amount of zinc needed for flat tappet cams, like most oils today.
  11. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

    Here is how I normally adjust mine,but Im the one having a problem,what do you think of this method,Iv used it many times in the past on my Fords I havnt done a whole lot of chevys but I wouldnt think there should be much difference,
    If using a
    hydraulic camshaft and no specifications are available,
    turn the rocker arm adjusting nuts 1/2 to 3/4 of a turn
    past zero lash.
    A) Following the proper firing order for your engine, turn the crank
    shaft until the first cylinder listed in the firing order is at TDC on
    the compression stroke. Both valves will be in the closed position.
    B) Adjust the valves as described, then rotate the crank exactly 1/4 turn
    and repeat for the next cylinder in the firing order.

    thanks jim
  12. Basically it started ticking 10 minutes into its break-in period. I can't see a cam (freshly lubed) wearing enough to cause lifter clatter in such a short amount of time. I'm still thinking it just isn't adjusted correctly.

    Hmmmmm .... unless one or some of the lifters weren't/aren't rotating .... THAT might cause them to wear very quickly, and as they wear you would hear the dreaded "lifter tick".

    I suggest checking the studs first, then readjusting the rockers cold ... might be a good idea to try another method of adjusting them just incase your present method is actually causing the ticking issue. If it sounds like several lifters ticking then I doubt it is your fuel pump.

    Those engine should accept factory roller cams ... any chance you are using the shorter "roller" pushrods by mistake (not even sure that is possible, just crossed my mind and thought I'd toss it out there).
  13. Try my method of adjusting the rockers (posted it earlier) ... I am not a Ford guy and have not adjusted a Chev the way you describe. Are you aware that the firing order is different on a Chev? The method I posted is directly out of "How to Rebuild Your SBC" book. I have never had a problem adjusting rockers the way I described.
  14. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

    Yes it is a mild cam and matching springs,Its a later block so I had to run an electric pump..Fiddy I read it does some where a while back,I really hoping I didnt screw up the break in,,,,jim
  15. "Fiddy I read it does some where a while back"

  16. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

    Borntoloze,,,this is a "pre vortec non roller cam motor"...I will give your valve adjust method a shot in the AM and post results tomorrow,,,,thanks again everyone,,,jim
  17. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

    "Fiddy I read it does some where a while back",,,,meaning I read it had enough Zinc for cam breakin,,,,jim
  18. Pre-Vortec engines can have roller cams or can accept factory roller cams. '92-'93 Buick Roadmaster has a roller cammed 350 that is not a Vortec engine. Your '92 should have all the "bosses" and drilled/threaded holes (under the intake for the "spider") and the machined surface and the drilled/threaded holes for the cam retention plate, regardless of whether or not the engine left the factory with the roller cam.

    I have a '95 P-up 350 that I installed all the Roadmaster roller cam stuff into. Complete bolt-in using all factory stuff (used an carb intake rather than the TBI though).
  19. Sorry :eek: ... didn't realize someone named "Fiddy" was posting answers, I had no idea what the heck you were talking about :D

    Best of luck
  20. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

    Well I pulled off the valve covers and took a good look,I found on #1 rocker was very loose ,and the intake stud had alot more thread showing then the others and the belly of the rocker was real close to the head. Not good!! so I pulled the intake hoping for a collapsed lifter and wasnt that lucky.... the lifter was sunk in and the surface looks like the bottom of a shot glass,flatten the cam lobe Im sure,I cant believe it did all this inside of an hour of running,so Im in tear down mode and a new cam,lifters and breakin lube is on the way...
    thanks again for the help.....jim
  21. Gotta watch the flat tappet cams with our modern oil. Not that long ago (3-5 years) the trick was to run diesel oil like Delo or Shell's Rotella, but now they are pulling the zinc out of those oils also.

    You need to run an additive like ZDDP or buy Racing Oil from Valvoline or whomever you prefer. The racing oil still has the zinc in it last I heard.

    I flattened a cam within 5 minutes during break-in on a Pontiac doing exactly what you did. I thought I was okay with the diesel oil. I called the cam company and the first question was "Did you add ZDDP?" I had to eat the cost of the cam, but the next one I bought came with a free bottle of ZDDP. The cam company decided to just include it with every cam they sell now so they can free up some phone time.
  22. Big time bummer... guess I've been lucky over the years and have never lost a cam like that. I always applied the cam lube that came with the cam, or used my own. I have always used racing oil, since most of my builds were stock car engines. Just take your time getting it back together and you'll be okay.

  23. porknbeaner
    Joined: Sep 12, 2003
    Posts: 38,751


    An exahust leak can sound like a loose valve lash as well.

    I use poly locks on all my stuff even if it is stock. I have had bad experiences with the stock adjuster nuts on GM motors.
  24. Standard gas&oil
    Joined: Dec 3, 2010
    Posts: 289

    Standard gas&oil
    from USA #1

    Cut your oil filter open and check for metal, or if you have a magnetic pan plug see if it is covered with metal shavings.Run it on the street and see if it backfires thru the carb. If it does there is a good chance the cam lobe went flat.
  25. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 3,879


    Ouch, never a good thing when a new cam goes flat. Any engine I build I'll break in on a run-in stand, so that if there is an issue (no serious ones yet) it's a bit easier to deal with.

    It would be a good idea to pull a couple main and rod caps to inspect the bearings. Chances are the cam started to go flat immediately, and if you were running the engine at 2000 RPM with cold oil, it's likely the bypass in the filter was open a bit, letting unfiltered abrasive oil get to the bearings.
  26. unkledaddy
    Joined: Jul 21, 2006
    Posts: 2,857



    If your block has the accommodations for a roller cam you might think about spending a few extra $$ and take the worry out.
  27. Post some pictures of the lifter valley under the intake manifold. This engine "should" accept all the factory roller cam stuff (and the pics would help verify this). The oils aren't going to be getting any better, now would be the time to switch it over to roller. As mentioned before, I found all the factory roller stuff (lifters, cam, "spider", "dogbones", cam retention plate) at the wreckers for cheap. You also need to change your timing chain set (backside of large gear has clearance for the retention plate) and you also will need to run a "melonized" dist drive gear (avail from dealer). If you engine will accept roller, you can totally avoid all this ZDDP stuff and the need to break in the cam.

    I find it hard to believe the cam/lifters wore enough after 10 minutes of run time to cause an audible tick ... something (more than just the lack of ZDDP in the oil) wasn't right to begin with (just my opinion). Sounds to me like some of the lifters weren't turning or maybe Summit cams and lifters are made from Chinese Craptonium castings.

    Don't forget, all the "missing metal" from your lifters and cam lobes went somewhere.

    Edit: I said "I find it hard to believe the cam/lifters wore enough in 10 minutes of run time to cause an audible tick" ... not saying it didn't or couldn't happen, just saying (especially in this case with a mild cam and therefore mild spring pressure) that I have never (myself) heard of one failing so quickly. A monster flat tappet cam with major spring pressure ... maybe ... but this ???
    Last edited: Feb 23, 2012
  28. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

    I wish it was a roller block, I rebuilt this engine 5 or 6 years ago its been bagged sitting in my garage,when i was recently adjusting the valves and doing finally assembly to put it in it looked like the assembly lube was sort of dryed up (I noticed that on the rocker to valve tips) I did pour the oil in all over the valve train and all over the lifter valley before I put the valve covers and intake on figure that would take care of it. My guess between the assembly and cam lube being dryed up and not realizing the lack of zinc in the new oils may have done it in.
    This time I picked up Rotella Oil,new cam and lifters are freshly lubed up,I got some Crane oil additive for the breakin... I cleaned and flushed things out the best I could without doing a major tear down and Im going to roll the dice with it and slam it back together and hope it last... By the way Im not a mechanic im a bodyman for the last 35 years I know just enough about engines to cause myself alot of pain...the truck is kind of a pile anyway I just need a work horse pickup and choose this avenue,,, here is a link to some photos of the engine and the damaged lifter... Thanks again for all the great responces
  29. jimcaf
    Joined: Feb 12, 2008
    Posts: 122

    from san diego

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