350 valvespring damage?!?!!!?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by greg83k5, Nov 19, 2001.

  1. greg83k5

    greg83k5 1/2 ton status

    Nov 2, 2001
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    space sity houston, texas
    engine ran fine before i pulled it out, 'cept a banging noise from the right bank. pulled motor, and all the rocker arms were loose, one so much so that the rocker actually fell off the pushrod......

    on the #5 piston, both 'oil shields' broke and are resting at the base of the spring assy, rather than up by the top of it.... why did they break? also, there appears to be chunks of something that broke up right by one of the oil drains at the end of the bank- the assemblies are all free, and nothing looks broken, of course the head is still on the block...... oh, the chunks weren't ferrous, ( non-magnetic ) could they be part of the bronze valve guides???

    whaddya think????

  2. chevyracing

    chevyracing 1/2 ton status

    Sep 8, 2001
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    The drain holes for oil in the heads were pretty rough castings in most cases, so it may look like something is broke there and actually isn't. The valve spring being bent up like that sounds like either a lifter pumped up and over compressed the spring or a valve stuck and got struck by the piston causing the valve to moved at an awkward angle against the spring.
    Hard to tell without looking at it. Did you pull the valves out and check the guides? Have you checked the lifters? How many miles is on the motor? Was it over revved? Do you have a huge cam and what is the lobe center on the cam? Were the timing gears aligned propperly?

    Lots of questions on a scenario like that.


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  3. dyeager535

    dyeager535 1 ton status Premium Member

    Dec 13, 2000
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    Roy WA
    Valve guides, IIRC, usually protrude out of the head a bit...if the valves saw some side load (rocker slid off the valve stem) it might break the protruding section off. Just an idea, there isn't much thats non magnetic in a chev motor : )

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