Kwik88

On my AFR 190s this is the third rocker stud that has broke. Two of them has broke while just idling. Any ideas as to why? I'm not sure what kind of hardware AFR using with their heads. I guess I'll pull the rest of them and replace with a set of ARP studs. Has anyone else ever had this problem?

RednGold86Z

iTrader: (1)

Rocker arms that don't have enough travel (long slot for stamped) will bind on a large cam. Check that out, I guess. Bad geometry (like too long or too short push rods) can also put bending load on the rockers (the tips could be pushing against the valve stems, or rocker is running out of travel). Studs are only meant to live with force along the axis.

Kwik88

I'm using 7.2 lenght push rods, 1.6 comp roller tip rockers, and the cam is a cam motion with .574 lift intake and .582 exh. I'm also using a set of comps 875 hyd.roller lifers with a 1/4 turn preload on them. The only thing that I can think of is bad studs that came with the heads. I was just wondering if anyone else has run into this problem.

RednGold86Z

iTrader: (1)

Yes, others have had similar problems. But, that's a lot of lift. Did you get the right springs? Coil bind can break studs too.

ede

did you check push rod length and the geometry?

Schultzy89GTA

As mentioned, make sure geometry is correct. Having said that, the studs that AFR ships with don't seem to be up to snuff. Save yourself more hassle and heartache and just by the ARP studs and be done with it. I had one of the AFR studs go and switched to ARP. No problems since. A bit less lift than you at .565.

I love my AFR heads but if I were to do it again knowing what I know now, I would have ordered bare heads and put my own hardware on.

Good luck.

-Schultzy

89gta383

iTrader: (5)

Get some arp studs. The ones on the afr heads are crap. I broke one idling in the driveway.