stock valve springs

Discussion in 'Engine Topic' started by shanep91, Nov 9, 2009.

  1. shanep91

    shanep91 Member

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  2. doc221978

    doc221978 Veteran Member

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    Not only will the stock springs fail immediately...... if it is a stock engine it will too. Cams like that need more compression, higher flowing heads, and if you rev to 7k rpm's it needs a bullet-proof bottom end. You need to match all the components together to get the most out of it.

    That would be hell to drive on the street too. For a flat tappet cam, I wouldn't go above around a 268 or 272 cam. For a roller, I am happy with my xr 282. That 282 is a little rough on the street.
     
  3. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    Either of those cams would be a waste on a stock head/spring combo. Even the best flowing vortec heads will need worked for those cams.

    Like Doc said, you will need to match your entire engine combo to realize any gains from those cams.

    You don't have much posted in your siggy. What do you have, what are your intentions, and most important; what is your budget? It's all got to work together.
     
  4. shanep91

    shanep91 Member

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    its a 1990 chevy 350 with stock bore but has flat top pistons and the heads have 202 160 valves in them, they are shaved down, i think ill have about 10:1 compression, the heads are heavily ported too
     
  5. 1BAD78

    1BAD78 Veteran Member Gold Member

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    not only would the stock spings break.they would probably bind and flatten the lobes.i had a crane 266 break every damn valve spring in a stock head i used back in the day and it only had like .440 lift.and really that is way too much cam for a pretty much stock short block.
     
  6. z28rod

    z28rod Veteran Member

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    stock springs are good to .480 lift , z28 springs are good to .500 lift.
     
  7. pdq67

    pdq67 BANNED

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    "I had a crane 266 break every damn valve spring in a stock head i used back in the day and it only had like .440 lift and really that is way too much cam for a pretty much stock short block."

    Calling BS here b/c the Crane 266/266 Energizer is a dandy 2-up from stock cam imho.

    Something wasn't right??? Hell, -929 hy-cam stock springs, ALTHO QC'd, were used on the old 30-30 solid lifter cam so I don't buy it!

    And right, match your CR w/ your cam and if you want more help, then post back your CR, (OR YOUR ENGINE COMBINATION), and we will be all over this like flies on sh*t!!

    Head chamber cc, headgasket thickness, piston type, DITH piston depth, etc., etc...

    At least I will be.......

    pdq67
     
    Last edited: Nov 10, 2009
  8. rustbucket79

    rustbucket79 Veteran Member

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    Spring bind and seal to retainer clearance is a big concern on any engine (must be checked) but flat top pistons and 2.02 intake valve requires an extra level of inspection since there are several cast flat top pistons out there that give questionable radial clearance with the larger diameter intake valve.

    Stock "tall" small block springs will take a suprizing amount of cam lift, but won't give nearly the control required for a performance cam, which is why pretty much "ANY" performance cam lists the required springs.
     
  9. Simon@London

    Simon@London Veteran Member

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    I just found out what the wrong springs do to a motor. This Hotcam was great on old vortec heads until you went past 5,100 then things got wonky.

    I soon found rockers making noise with some messed up internals after revving it past 5500 a couple of times. That was with stock vortec springs so now I went with screw in studs & Bee Hives and it's very smooth up in the upper rpm zone now.
     
  10. pdq67

    pdq67 BANNED

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    Oh, and btw, I ran my stock 350SS engines -929 cam springs w/ my 1200 miles from new installed -151 cam w/ .447" lift for years as my DD.

    Took her up above 6,000 rpm many times.

    pdq67
     

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