Broke another rocker stud: info only
#1
Le Mans Master
Thread Starter
Broke another rocker stud: info only
I was just sitting at idle after a heavy run when the engine started missing, and I turned the radio down, and opened the window.
I could hear a loud clack clack clack.
I knew the sound, I broke another rocker stud.
I just idled the car in gear with the flashers on till I got home.
When the car cooled off, I pulled the left rocker cover, and found another stud broken.
I removed all the roller rockers and I installed a set of Comp Cams roller tipped investment cast rockers.
After I was finished adjusting the valves, I had almost 1/2 " of stud showing above the adjusting nuts on the rocker studs.
I think the roller rockers just didn't allow enough stud to be in the poly locks, and the tips of the studs were taking too much stress.
Just for info, when using roller rockers, install the rockers, adjust the valves, shut the engine off, and remove a rocker, and reinstall the poly lock without the rocker. If there isn't more than half of the stud in the poly lock, you are close to reaching the structural limits of the factory studs.
Best to get stronger studs or change to a lower riding rocker.
This is the third stud that has broken.
Last edited by coupeguy2001; 08-26-2011 at 01:21 AM.
#4
Race Director
Member Since: Jan 2003
Location: Summerland B.C. Canada
Posts: 19,667
Likes: 0
Received 36 Likes
on
32 Posts
I had the same situation with my rollers and studs, less the breaking part. I didn't feel comfortable with the lack of full thread through rocker nut, so I bought the ARP set that are about a 1/2" longer.
#6
Le Mans Master
Thread Starter
When I set up the engine initially, the pushrod length was adjusted to give a center wiping surface on the tip of the valve.
It is a 383 wih 113 heads. Basically, with the low engine speeds on the freeway, it is basically patterned after a chevrolet HT383 crate with a zz409 cam. It does have a scat crank with SRP 14cc dished pistons with the piston tops contoured for valve relief.
If I went with longer studs, I would have to change the rocker covers.
I would not be able to keep my "stealth" appearance.
Right now, I can still cross my fingers and explain that a L98 has 230 HP with about 300 lb feet of torque. Then I light 'em up really easy and pass it off as a 3.07 low gear in the trans....
It is a 383 wih 113 heads. Basically, with the low engine speeds on the freeway, it is basically patterned after a chevrolet HT383 crate with a zz409 cam. It does have a scat crank with SRP 14cc dished pistons with the piston tops contoured for valve relief.
If I went with longer studs, I would have to change the rocker covers.
I would not be able to keep my "stealth" appearance.
Right now, I can still cross my fingers and explain that a L98 has 230 HP with about 300 lb feet of torque. Then I light 'em up really easy and pass it off as a 3.07 low gear in the trans....
Last edited by coupeguy2001; 08-26-2011 at 10:30 AM.
#10
Race Director
Member Since: Jan 2003
Location: Summerland B.C. Canada
Posts: 19,667
Likes: 0
Received 36 Likes
on
32 Posts
FWIW, I am using some of the bulkiest rollers out there, under my stock covers and my aftermarket short covers.