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Boat Nut
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Discussion Starter #1
At what cam lift do you need stud girdles? The engine in question is a Ford 496 stroker, using 6.7 rods. Broke a rocker stud tonight, tore it down, and found many of them bent. The heads are FMS SCJ's no markings on studs, and they came in the heads. Will ARP studs do the trick or is more needed?The cam is a 650 lift isky roller. Thanks
 

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steelcomp was here
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A stud girdle isn't going to solve your problem. It sound slike you have some geometry issues or spring bind. What rockers are you running?
 

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Boat Nut
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Discussion Starter #3 (Edited)
Comp Pro Magums 1330-16 Ford V8 429-460 7/16" 1.7. I did find the lash to be a little big, the cam card called for .022 and .024 hot.
One other note, theses heads are far from new, they were off a mustang II drag car pryor to present duty in a boat. The thread goes nearly all the way to the base of the stud, this is where it broke, which may also have contributed.
 

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Comp Pro Magums 1330-16 Ford V8 429-460 7/16" 1.7. I did find the lash to be a little big, the cam card called for .022 and .024 hot.
One other note, theses heads are far from new, they were off a mustang II drag car pryor to present duty in a boat. The thread goes nearly all the way to the base of the stud, this is where it broke, which may also have contributed.
Soft spring it and check for rocker bind. Or just check with the springs you have on now. As stated prior, you have a geometry problem in the upper valve train area and it needs alittle TLC. Pay close attention to rocker slot length and rocker angle at max lift. You have a bind somewhere and it will drive you nuts if you don't get it gone. IMO. M
 

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A stud girdle isn't going to solve your problem. It sound slike you have some geometry issues or spring bind. What rockers are you running?
As Steel Comp stated you have a geometry problem somewhere and until that is addressed nothing will get better. Age of the cyclinder head and all else does not matter. A stud girdle will not fix a bind. They will only fix a flutter problem at probably alot more rpm than you will see. no offense intended. I have ran and raced 429 fords and never had a problem turning 6k. But I personally don't go along with the big cam theory. Flow caracteristics and volume that the motor can flow tell me how to cam a motor for what I want. Over feeding creates a mess as far as I have learned. Side Note. Are you running iron heads or aluminum. If iron are they DOVE-C heads.M
 

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Boat Nut
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Discussion Starter #6 (Edited)
The heads are aluminum. Looing at the break point, it's at the base of the threads, thats about where the bottom of the pivot is on the rocker. Also appears is was there for some time, a little is dark and oil impregnated, rest of the break is clean, may well have been like this. The geometry will be checked over once again as well, the cams not that big.
It was'nt untill all the studs were removed you saw the bent studs. Will get to the bottom of it for sure. Thanks
 

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steelcomp was here
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Sleek...the only thing that breaks rocker studs is binding somewhere. You could be binding the springs (bottoming them out), you could be hitting the top of the guide with the retainer, or if the pushrods are too long, you could be over arcing the rocker to it's travel limit (least likely with rollers). Check for bent pushrods while you're at it. Since it's a solid roller, better check your lifters for smooth rollers, too. You may have damaged them. It takes a lot of load to break a stud. Re assemble a cylinder and rotate the engine through a vew revolutions and see what's going on in those areas. The cam is big enough that if the wrong springs were installed, they could be binding.
 

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Replace them

Replace ALL the rocker studs with quality studs and be sure they're long enough. Buy a quality girdle, cheap insurance. The valve train takes a beating, the weakest link WILL fail and any help you can add could make a difference. All the safe guards in the world won't prevent failures if the geometry is screwed up..........MP
 

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Boat Nut
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Discussion Starter #10 (Edited)
Sleek...the only thing that breaks rocker studs is binding somewhere. You could be binding the springs (bottoming them out), you could be hitting the top of the guide with the retainer, or if the pushrods are too long, you could be over arcing the rocker to it's travel limit (least likely with rollers). Check for bent pushrods while you're at it. Since it's a solid roller, better check your lifters for smooth rollers, too. You may have damaged them. It takes a lot of load to break a stud. Re assemble a cylinder and rotate the engine through a vew revolutions and see what's going on in those areas. The cam is big enough that if the wrong springs were installed, they could be binding.

Every thing appears ok, have an extra .100 before spring bind would happen. The lifter was kicked out of the bore, the H bar was knocked loose.
Everything is back together, and back to normal. Took the bad stud into have it looked at by machinst, was determined that it was indeed cracked prior to this build. Thanks for the tips steelcomp
 
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