Seriously! I spend 3 hrs. taking my rocker shafts on and off to fix the next stripped bolt hole. My favorite part is I would get them all in and be torquing them down for the last time and the LAST one, with out fail, would strip out. AAAAAAHHH!!!!!
OK If you are about to swap out anything on the rockershafts and you have to take them off. Save yourself a crapload of time and just go ahead and drill out and heli-coil them all right away. GEEZ!!!
I swear! It's like screwing a bolt into icecream or candle wax!!
I wonder if a stud setup wouldnt be better.. I sure ARP has something that would work.
There is little doubt in my mind that it would. I think it's the shear forces combined with the stress and out they come. I used some altra-slick assembly lube. That may have helped the last couple times in... 4 of the 8 holes are helicoils now. I know the helicoils make a stronger threaded hole so it's the other holes that are a problem now.
Studs would definitely be better. The bolts haven't given me trouble personally, but I understand that one of these bolts tore loose on Jerry Richards' MGB GT V8 racecar at V.I.R. in June, and it ended his weekend early and in extreme frustration. (I think it was the rearmost bolt hole, by cylinder 7, and that the rocker shaft was damaged when it happened.)
Yep, that's about the most frustrating thing about these engines, and it's not just the rocker bolts either.
Jim
The T&D shaft rocker setup Im using on the Chevelle has a stud setup.. My springs are 530 Lbs open. so yeah I can definitely see the need for studs... ARP has a full line of fasteners.. Im sure it wouldnt take long to come up with the necessary part numbers to create a stud set for just about anything.
Nic, Helicoils are only, slightly stronger than virgin threads. I suggest peeping "Timeserts",webbsite.In my mind their the best. Are you using the Volvo shafts and rockers? Studs, always best, when you add-up the "poundage" your compressing with minimal thread engagement, using bolts. I'm thinkin a"lip" on pushrod side of stand/bottom, might help. Good Luck, roverman.
Geez. Now I'm nervous. Maybe I'll look into studs. Hmmm.
How is lubrication to the rockers solved with using studs instead of shafts? Is it like the traditional way through the push rod?
The oil goes around the bolts or studs.
Jim
I'm blocking off the oiling through the rocker shaft and oiling through the push rods instead. I had to shim up the rocker shafts and I used the shims to block the oil passage. This engine over oils the rocker shafts anyway so that will leave more for the mains!