Crane gold roller rocker failure
Thread Starter
Drifting
Joined: Nov 2000
Posts: 1,390
Likes: 39
From: North Brunswick NJ
Crane gold roller rocker failure
I was having troulbe keeping my solid tappets ajusted, especially numer 7 exhaust. I pulled the intake to check the roller liftrs for wear, but everything looked fine. I never looked at the rockers. Last weekend coming back from a show one of the tappets made so much noise that I wasnt sure I was going to make it home. This was heard over a very loud side exhaust system. I pulled the valve covers and found the rocker very loose on the number 7 exhaust. The tip roller was fine , but the piviot that rides the 3/8" stud was very loose and the roller bearing were laying in the head by the vale spring.
Has anyone else had problems with these rockers? I thought that they were the best on the market.
Ed
Has anyone else had problems with these rockers? I thought that they were the best on the market.
Ed
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Crane gold roller rocker failure (ED DINAPOLI)
I beat the needles out of aluminum RR's before so I switched to steel. But that was in an extreme motor. I also use ARP 7/16th studs and a stud girdle. Allen locking nuts and the girdle make valve adjustment a rare thing like 3-5000 miles between even bothering to check.
Your failure was probably caused by it being loose and it just got beat to death
Your failure was probably caused by it being loose and it just got beat to death
Melting Slicks
Joined: Jun 2000
Posts: 3,215
Likes: 6
From: Tampa Florida
Re: Crane gold roller rocker failure (ED DINAPOLI)
That is a bummer.
Hope you find all the needles, etc.
Also these are similar to what Chevy used on stock LT4's so durability should be good, unless it is a lemon... :confused:
Hope you find all the needles, etc.
Also these are similar to what Chevy used on stock LT4's so durability should be good, unless it is a lemon... :confused:
Thread Starter
Drifting
Joined: Nov 2000
Posts: 1,390
Likes: 39
From: North Brunswick NJ
Re: Crane gold roller rocker failure (No Go)
Gull,
This is not an extreme motor, only see's 6,000rpm. could have been loose an wore itself out. Why would steel be better? These thing are all steel sleeved.
No Go,
I believe I got all the rollers as the fell into the part of the head were the oil pools from gravity. I think you are correct that these are the same rockers chevy used. Could have been just a bad one also.
Ed
This is not an extreme motor, only see's 6,000rpm. could have been loose an wore itself out. Why would steel be better? These thing are all steel sleeved.
No Go,
I believe I got all the rollers as the fell into the part of the head were the oil pools from gravity. I think you are correct that these are the same rockers chevy used. Could have been just a bad one also.
Ed
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: Crane gold roller rocker failure (ED DINAPOLI)
Interference can cause this too.
Take a look at the underside of the rocker arm and see if there is any inidcation that the rocker was riding against the valve spring retainer.
I use to always have this problem with Crane Gold's on BB Chevy's and had to grind the underside of the rocker for the needed clearance.
If the broken rocker is all chewed up and you can't tell, take a look at the others. Chances are that one or more will show signs of contact if interference is the contributing cause.
Look closely at the underside of the valve cover for any sign that the rocker(s) were hitting the cover/drippers. Check between the coils of the valve springs for shinny areas indicating coil bind and while you're at it check for any that may be broken.
Broken springs can sometimes be hard to find so take your time, use a really bright light and look all around each spring, using your fingers to detect any sign of a break.
Any interference can cause the trunnion bearings to be side loaded, wear will greatly accelerate and failure follows.
Keep us posted.
Jake
[Modified by JAKE, 4:47 PM 9/28/2002]
Take a look at the underside of the rocker arm and see if there is any inidcation that the rocker was riding against the valve spring retainer.
I use to always have this problem with Crane Gold's on BB Chevy's and had to grind the underside of the rocker for the needed clearance.
If the broken rocker is all chewed up and you can't tell, take a look at the others. Chances are that one or more will show signs of contact if interference is the contributing cause.
Look closely at the underside of the valve cover for any sign that the rocker(s) were hitting the cover/drippers. Check between the coils of the valve springs for shinny areas indicating coil bind and while you're at it check for any that may be broken.
Broken springs can sometimes be hard to find so take your time, use a really bright light and look all around each spring, using your fingers to detect any sign of a break.
Any interference can cause the trunnion bearings to be side loaded, wear will greatly accelerate and failure follows.
Keep us posted.
Jake
[Modified by JAKE, 4:47 PM 9/28/2002]
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Crane gold roller rocker failure (JAKE)
They kind I beat up had needle bearings riding right against the aluminum rocker. You could actually see needle bearing dents in the on the ones we popped apart.
Jake might be on to something. Geometry could be off. You might need .100 push rods. I'm running .100 longer length valves and .200 longer push rods to clear everything
[Modified by gkull, 9:08 AM 9/30/2002]
Jake might be on to something. Geometry could be off. You might need .100 push rods. I'm running .100 longer length valves and .200 longer push rods to clear everything
[Modified by gkull, 9:08 AM 9/30/2002]
Thread Starter
Drifting
Joined: Nov 2000
Posts: 1,390
Likes: 39
From: North Brunswick NJ
Re: Crane gold roller rocker failure (gkull)
Jake/Gull
I will check the geometry as it culd be off. I looked close at the rocker and it does show a slight scuff mark. It is hard to tell if this is before or after the problem occured. I am using .100 longer push rods, and the clearance to the spring seems ok. I have replaced the the bad rocker with another gold Crane rocker. I will surely watch this closely. I dont think any of the metal got into the motor, but this is not something I want to happen again.
Thanks for your help.
Ed
I will check the geometry as it culd be off. I looked close at the rocker and it does show a slight scuff mark. It is hard to tell if this is before or after the problem occured. I am using .100 longer push rods, and the clearance to the spring seems ok. I have replaced the the bad rocker with another gold Crane rocker. I will surely watch this closely. I dont think any of the metal got into the motor, but this is not something I want to happen again.
Thanks for your help.
Ed
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Crane gold roller rocker failure (ED DINAPOLI)
Ed. I don't know how big of springs your running. But if you put a straight edge across the top of all your rocker studs. What amount of defection are you getting on the ones at max lift? If it's over .030 it's to much. I also don't know how your arrived at using .100 over. But with correct lengths and stiff studs all of your roller tips will stay nearly centered on the valve stem tip as you rotate the motor over. you will see a small amount of travel back and forth. But it should be minimal.
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Thread Starter
Drifting
Joined: Nov 2000
Posts: 1,390
Likes: 39
From: North Brunswick NJ
Re: Crane gold roller rocker failure (gkull)
gkull,
I just noticed I spelled your name incorrectly,sorry, so much for my tying skills. The .100 came from Edlebrock with their head insrtuctions. I am not sure how to do the measurment that you indicated. Is this at full lift of the valve being measured against the adjacent valve that is fully closed? Thanks for your help.
Ed
I just noticed I spelled your name incorrectly,sorry, so much for my tying skills. The .100 came from Edlebrock with their head insrtuctions. I am not sure how to do the measurment that you indicated. Is this at full lift of the valve being measured against the adjacent valve that is fully closed? Thanks for your help.
Ed
Burning Brakes
Joined: Jul 2000
Posts: 963
Likes: 0
From: melbourne,Australia
Re: Crane gold roller rocker failure (ED DINAPOLI)
Ed,there is an article in last months Chevy Hiperformance on exactly this issue including how to make sure your geometry is correct and how to optimise the roller contact to prevent side loading.....unless the one rocker was a manufacturing dud,it is probably a problem with the geometry...john :chevy ;)
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: Crane gold roller rocker failure (ED DINAPOLI)
What I'm talking about is the max deflection. If you put a straight edge straight down your studs. If you have enough spring pressure it will bend the studs back and forth. Over time with aluminum heads even with guide plates it will ruin you heads threadsand it causes a wipeing action on top of the valve stems. side thrust and the guides go. That's the reason for stud girdles
Instructor
Joined: Sep 2001
Posts: 171
Likes: 0
Re: Crane gold roller rocker failure (gkull)
From my POV, forged aluminum rods/rocker arms have no place in a durability (and street) engine. I for the life of me, do not see the rationale in GM using aluminum r. arms in the LT4. :U Must have saved a buck or two.
