here's some photo's of the damage to one of my gn1 aluminum heads. anyone experienced the pedestal breaking off like this? my other head is excellent with no signs of the cracking starting like the pedestal in the picture. heads were just redone with new springs (flat tappet) so spring pressures not that excessive. appears that the breakage occurred at the bottom of the bolt, but the heli coil doesn't go to the bottom of the hole. sent head to Tom at champion for repair. not sure what's the cause as its only the one head and everything checks out ok. thankfully only doing a burnout when this occurred and no valves bent or bottom end damage. comments from anyone that has seen or experienced this please post, curious to know what's up.
broken pedestal champion gn1's
- Thread starter snzuloz
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i have never heard of this happening, sure you did not have any coil bind or some sort of other issue to put alot of stress on the valvetrain? i would think a pushrod or rocker would go before the pedestal, BUT thats IF there was a issue with coil bind,etc.
If the valves floated and bounced lifters off the cam something like this could happen. Ive seen many stock rocker arms/shafts break from over revving. Maybe the pedestal is the weakest point when running the factory style pedestal GN1. Have him check the valves on that cylinder for runout. They may have bent a little. They can be tapped deeper and a long heli-coil used.
valves have been checked and are good. no coil bind to speak of. have not noticed any overrevving, shifting set at 5500 rpm and big stuff3 rev limiter set at 5800. dyno'd engine at 650 hp and almost 700 ft/lbs of torque and a safe tune with 21 degrees timing and 20-24 lbs boost. have broken stock rocker shafts previously but did not expect to break the pedestals. i guess the t@d shafts are to solid
nobody else seen this?
nobody else seen this?Saw that on a friend's motor. Local machine shop welded it back on but they didn't move the insert down below the weld. I told him it would pop back off, and it did in a week or so. If you do just have them weld it back on, make sure the insert threads go below the weld so the repair is in compression, not tension, and just use a longer bolt or stud in that hole. Absolute best repair is to send the heads to Champion and have them converted to 14 bolt style, and buy their stock shaft adapter stands. I think it totals less than $300 and it will never happen again.
mikestertwo
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This is a long shot but does the radius of the rocker shaft match the radius of the pedestal?
boostingbuick
Going to be buried in this.
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Did it get droped? Did you find this when you pulled it apart?
i don't believe that it got dropped. the bolts were still tight on both remaining pedestals. Tom tells me a 4-5 day turn around time, hopefully this happens as i need to run the car at least once down the track this year with all the new stuff. still can't see what caused this to happen, thought maybe others have had similar problems.
trbochrgd1
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- Feb 2, 2005
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I had the same thing happen to me! Same exact spot. Identical split. Tom also told me it would take 4-5 days to repair.
I got my heads back after about 2 months. (I think I am being generous) I don't have it back together yet so I don't know if the repair is going to hold. The repair does look good and they do great work and they have great products, but there customer service leaves a little to be desired.Your best bet is to call Champion. Their url is CHAMPION Racing Heads but it doesn't have much info.
