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Rocker help

  1. #1
    Senior Member gregb's Avatar
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    Default Rocker help

    Help with a rocker question. As you can see in the pic this one is severely overheated. The pivot wore out and the rocker came off the valve. It's a new engine, small block Chevy 383. I've built my share of engines, but this is my first experience using a roller cam (hydraulic). I broke the engine in with a single set of single valve springs that were on the heads, since they only had about 20 hours on them. I know rollers really don't require a break in like a traditional flat tappet but since springs are easy to change on a small block I wasn't taking any chances. Ran it for an hour or so in the boat (no driveshaft to the jet) and then took it for a spin in the local lake to work out any bugs. Didn't hammer on it too much since I didn't want to float any valve and the lake is pretty small anyway, but I got the RPM's up a few times. So I changed the springs to a dual set, they had more pressure than the recommended ones since the ones called for wouldn't fit the World Heads without removal and machining. But not much more, only about 20 #'s, ended up being 155 closed and about 340 open, I don't have my build notes with me but those are the numbers I remember. And I've seen different companies call for similar pressures for less cam. It's not a big cam only .520 lift. Those rockers were from the old engine, worked fine with the single springs during the break in and the first outing, and when I changed the springs they still looked normal. My question is "Did I just commit a rookie mistake?" When you start dealing with those kind of pressure does that become full roller rocker territory? Is that ball assembly just not up to the task? A few of the others look overheated also. I don't think it's a lubrication problem, I have 30 psi idling and 60 cruising, and the ball ends of the pushrod and the seat of the rocker don't show any signs of galling and I can't catch a fingernail on any part of the ball if I spin the pushrod but I will look for other signs if you can point me in the right direction. That damage took about 1/2 hour of being on the river with lots of full throttle blasts although it only turns the impeller 5K. So if I am going to need to step up to a set of rollers in addition to any other problems you might have insight to, which are going to be the best choice, aluminum or stainless? Thanks in advance for any help, I'd like to be back on the lake sooner than later.
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    Last edited by gregb; 06-30-2008 at 10:35 PM. Reason: spelling

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  3. #2
    Senior Member gregb's Avatar
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    The balls are grooved and they are Comp rockers. Used 15-40 Delo for breakin, changed it and went to the lake, changed it again to Mobil 1 before the fateful river run.

  4. #3
    steelcomp was here
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    "Did I just commit a rookie mistake?"
    Yup.
    340 is way too much for stock stamped rockers, even the slotted ball, high perf ones, IMO. A set of rollers is so inexpensive these days. You'll need some EOS these days with anything that has a flat tappet or ball fulcrum like that. Just not enough zinc in anything any more. That's the main reason it failed. High spring pressure and no lubricant in the lubricant. I think you could back down a bit on the spring pressure as well, especially if you're only turning 5000. You might even pick up a hun rpm.
    AFA rockers, aluminum rollers would be fine here. Crane, Sharp, Scorpion, etc. Check with Competition Products and you might get a deal on a set of Millers. Stainless would even be nicer if you want to spend the $$.
    If you;re not running any kind of performance oil pan, you might consider one. Not saying it was your problem, just a suggestion to help prevent this kind of thing in the future to other more expensive parts.
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    Senior Member gregb's Avatar
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    Thanks for the fast reply, I have an 8 quart pan and a Melling select pump. I run 6 in the pan and the one in the filter and the gauge never drops off like its running out, and I have both the electric gauge in the dash and a mechanical one on the engine. I tried to do it right but I'm still learning after all these years. I wanted to run less spring but the guide boss on the Sportsman heads is pretty big so that limits my choices for dual springs. Is a dual spring a necessity, or is a single spring with the right specs acceptable? Never occured to me about the lack of zinc on the top end.

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    Senior Member ol guy's Avatar
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    Gee, Does blue metal mean anything to any body???? This would be a clue Lack of oil??? M

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    steelcomp was here
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    Quote Originally Posted by gregb View Post
    Thanks for the fast reply, I have an 8 quart pan and a Melling select pump. I run 6 in the pan and the one in the filter and the gauge never drops off like its running out, and I have both the electric gauge in the dash and a mechanical one on the engine. I tried to do it right but I'm still learning after all these years. I wanted to run less spring but the guide boss on the Sportsman heads is pretty big so that limits my choices for dual springs. Is a dual spring a necessity, or is a single spring with the right specs acceptable? Never occured to me about the lack of zinc on the top end.
    Pan sounds fine. Depending on installed height, you might be able to come up with a single/damper spring combo that'll work. Maybe CStraub wil chime in here.
    If God is your co-pilot, change seats!
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    For what it's worth, I did the same thing to a set of Comp Cams stamped roller rockers about a year ago. I never did find out what was wrong and replaced them with some good aluminum rollers and no problems.

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    Quote Originally Posted by ol guy View Post
    Gee, Does blue metal mean anything to any body???? This would be a clue Lack of oil??? M


    I guess we need some more clue's ol' guy???

    I would agree that a lack of oil could do this, but the pushrod seats and ends look good so I am guessing it is getting oil. If he is running top end restrictors the problem could be magnified, but with the rockers he's using and 150/340 spring pressure failure is only a matter of time regardless of the amount of oil on them.
    I think Steel pointed him in the right direction........but what does he know!

  11. #9
    cfm
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    Can anybody post a bigger pic ? For some reason when I click on it it say's I don't have permission. It's not a red x and I'm logged in so I don't know what's up with that.

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    During breakin a ball and pivot type rocker will build a ton of heat quickly. You state you ran the engine on the water with the breakin springs, what was the seat pressure on these springs? What is the pushrod length you used?
    Chris Straub
    Straub Technologies

    3HP is an A$$ Whooping!!! JW

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    cfm
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    Quote Originally Posted by gregb View Post
    So I changed the springs to a dual set, they had more pressure than the recommended ones since the ones called for wouldn't fit the World Heads without removal and machining. But not much more, only about 20 #'s, ended up being 155 closed and about 340 open, I don't have my build notes with me but those are the numbers I remember.
    Comp's info states these rockers to be used with MAX of 350lbs open.
    http://www.competitioncams.com/techn...106-07/268.pdf
    To be honest, I've never used these, as I'm a stock rocker or typical full roller rocker person. No in betweens like these, cast full rockers, or what have you.

    I agree that the bluing is of course over heating. The diagnosis falls on your lap though if it's an oiling issue, improper assembly issue, or rocker arm/ball issue itself.

    When you do change rockers, the Scorpions are very good and one of the cheaper one's - other than the chinese poopo on E-Bay of course.

    With all roller rockers, before installing, clean out all the assembly lube out of the bearings and tips. Then soak in motor oil. Many do not do this because of not realizing the assembly lube is more for corrosion protection and not that good of an actual lube.

  15. #13
    steelcomp was here
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    I see that's not a stamped rocker, but one of Comp's Magnum rockers. Did these get a good coat of moly when installed new?
    No one ever seems to tell anyone when they're selling these that Comp says not to exceed 350# with these rockers. It's written in the catalogues, but unless they've changed things, you won't find it on any of the packaging. You were right on the limit.
    If God is your co-pilot, change seats!
    Acts 2:38, the perfect answer to the perfect question.

  16. #14
    steelcomp was here
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    CFM beat me to the point...except to say I think these are a good alternative in many applications. I've used them on SB Fords many times with no issues. It sounds like you had them broken in so my guess is that combined with going to M1, and the excessive spring pressure, you just exceeded their design limit.
    One more thing to note...I've seen them discolored before at the base, but the ball and seat were still fine. No galling or metal xfer of any kind, and still good surface integrity. This was using Valvoline racing oil, though. They had about 25-30K mi on them in a street/ off road truck that got it's share of abuse. I came to the conclusion that they were geting hot, but not to the point of destruction. This was with 300# springs (which is what they used to say was the limit on these rockers). Checked them from time to time and never any failure.
    Last edited by scott foxwell; 07-01-2008 at 07:39 AM.
    If God is your co-pilot, change seats!
    Acts 2:38, the perfect answer to the perfect question.

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