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Rocker arm question?

This is a discussion on Rocker arm question? within the Internal Engine forums, part of the LSx Technical Help Section category; Been considering these types of rocker arms. Scorpion performance 1.7:1 or the summit kit (looks like there made by Scorpion) ...

  1. #1
    Member Rob00Taws6's Avatar
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    Rocker arm question?

    Been considering these types of rocker arms.
    Scorpion performance 1.7:1 or the summit kit (looks like there made by Scorpion)
    or Comp cams Chromemoly steel rocker arms

    I'm also going to change the cam latter. I know a lighter valvetrain has its benefits, but Im really thinking of reliability and strength considering that i take my car in long trips. I would rather use aluminum provided that there strong enough for 14 hour drives.

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    Moderator Firebirdjones's Avatar
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    I'm a chromemoly guy myself. I have had crowers version of these on my chevelle for the last 12 years on 3 different motor combo's without issues on custom rollers with big spring pressure.

    And thats really what comes into play with rocker arm life expectancy. With mild spring pressures it's not an issue really. On many of my other cars I run aluminum bodied rockers that are of good quality and known brand name. My old firebird has had Harland Sharps on it for about 10 years now without complaint.

    My wifes 2000 SS had the crane variable ratio rockers installed at 40,000 miles, a daily driver that now has 64,000 miles and counting without issues. Been on 10 hour long road trips etc...

    I've only seen a couple of rocker arm failures in my lifetime. One was an aluminum body rocker on a high HP race engine with alot of spring pressure and who knows how many passes, it actually broke in half from fatigue. Probably not going to happen on a mild street engine.

    The other was a cheap brand of aluminum rocker where the roller tips were simply held in place with a cheap pin that was mushroomed on the ends to hold it still. These actually worked loose over time and the pin came out, roller tip falls off etc... So I would personally stay away from the cheaper brands and pay close attention to their construction.

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    Member Rob00Taws6's Avatar
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    I saw a picture if a failed scorpion ls1 rocker arm, on this sight. I wanted to run a 224/224 .563/.563 112 LSA thunder racing cam, and patriot performance 8401 springs. Im not set in stone. Any feedback is appreciated.

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    cutting and welding mark21742's Avatar
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    Quote Originally Posted by Rob00Taws6 View Post
    I saw a picture if a failed scorpion ls1 rocker arm, on this sight. I wanted to run a 224/224 .563/.563 112 LSA thunder racing cam, and patriot performance 8401 springs. Im not set in stone. Any feedback is appreciated.
    you lose a few degrees of intake duration, but I got a copy cam off of ebay for $115. (hr284 grind fresh copy) its a 220/224 .570/.580 with your choice of 112,114, or 116lsa. I went with the 112lsa and love it, a few other guys on here have bought cams from the same guy and have no complaints.

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    Member Rob00Taws6's Avatar
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    Quote Originally Posted by mark21742 View Post
    you lose a few degrees of intake duration, but I got a copy cam off of ebay for $115. (hr284 grind fresh copy) its a 220/224 .570/.580 with your choice of 112,114, or 116lsa. I went with the 112lsa and love it, a few other guys on here have bought cams from the same guy and have no complaints.
    Will keep that in mind, Thanks!

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    Moderator Firebirdjones's Avatar
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    Quote Originally Posted by Rob00Taws6 View Post
    I saw a picture if a failed scorpion ls1 rocker arm, on this sight. I wanted to run a 224/224 .563/.563 112 LSA thunder racing cam, and patriot performance 8401 springs. Im not set in stone. Any feedback is appreciated.
    Thats a very mild cam that won't require much spring pressure at all, shouldn't put any strain on the valvetrain. I wouldn't sweat running a good quality roller rocker with a cam like that on a daily driver.

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    Have you tried out the scorpion rocker arms.

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    Moderator Firebirdjones's Avatar
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    Nope, I prefer to stick with chrome molly construction like Crower or Comp Cams, especially for the big cam/spring pressure cars.
    I did however buy Harland Sharps for my 70 Formula only because nobody made a chrome molly version for a pontiac at the time. They have been on the car for 10 years now without a hickup.
    My wifes LS1 camaro also has full roller rockers from Crane, which are also aluminum. After 30,000 miles of street driving they have been fine with a mild cam and dual springs.

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  10. #10
    Don't waste your money on aftermarket rockers unless an altered valve angle requires you to do so. The stock rockers work best in most applications, and are lighter than ALL aftermarket rockers where it counts.

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    With that cam, I see no reason to buy a full roller rocker. The stockers are a good piece, and lighter then any aftermarket. Even the ultra light Yella Terra. If your heads have bronze valve guides or a non stock valve angle then you should run a roller rocker. Otherwise I would save my money.

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    Moderator Firebirdjones's Avatar
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    I am of a different opinion. GM should have put roller tips on these rockers to begin with. With roller cams easily exceding .500 lift or more valve guide wear becomes an issue. Then sucking oil problems and poor valve seating.

    You guys running even larger aftermarket cams with the stock rockers will be rebuilding those new cylinder heads again in 20-30,000 miles. I've been there. I personally don't even screw with stock type rockers anymore on any engine,,,,period.

  13. #13
    Quote Originally Posted by Firebirdjones View Post
    I am of a different opinion. GM should have put roller tips on these rockers to begin with. With roller cams easily exceding .500 lift or more valve guide wear becomes an issue. Then sucking oil problems and poor valve seating.

    You guys running even larger aftermarket cams with the stock rockers will be rebuilding those new cylinder heads again in 20-30,000 miles. I've been there. I personally don't even screw with stock type rockers anymore on any engine,,,,period.
    As long as you don't cheap out and use bronze valve guides that's not much of a problem.

  14. #14
    Moderator Firebirdjones's Avatar
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    Quote Originally Posted by Marc 85Z28 View Post
    As long as you don't cheap out and use bronze valve guides that's not much of a problem.
    Honestly it's a problem with cast iron guides as well. They will all wear excessively with high lift camshafts using non roller tips.
    When you buy aftermarket aluminum cylinder heads you don't have much of a choice other than bronze guides,,,as that's how most of them are manufactured.

  15. #15
    Veteran Hi-Po's Avatar
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    Thats true. Even AFR not REQUIRING aftermarket rockers... They usually use bronze guides. With either of the 2, bronze guides or aftermarket angle... full roller would fit the bill.

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