Gt40 3 bar heads Crane 1.72 roller rocker Went through to check adjustment because I was hearing what sounded like a few lifters making noise.... Went through using 1/4 crank turns going in firing order. All my exhaust were right at 1/2 turn to 20 ft lb tq spec after 0 lash. My intake rockers took almost a full turn.... Not a valve train guy but in my simple my mind that's telling me to get the Ford racing shim kit cause I'm putting way too much preload on the intake side. I've heard that light valve train noise for a while and finally checked them today. Also can gear slight popping in my exhaust....could this be connected? Am I correct in thinking I need to shim the intake rockers to get no more then 1/2 turn to 20 ft lb tq spec? Thanks
I have Scorpion pedestal roller rockers on my Cleveland and they just get torqued down - no adjustment
The pedistal rockers get torqued to 20 ft-lbs. It should take from 1/4 to 1 turn to reach that torque from zero lash. If it takes more or less you need to shim the rockers or change the pushrod length.
You don't worry about the amount of preload on the lifters? Maybe I'm over thinking it but I thought it was a big deal.
So I'm good as long as I'm not outside of the full turn? They were all within 1/2 to 1 turn. I thought it was no more then 1/2 turn.
Well... according to most cam manufacturers.. each 1/4 turn on a fine thread stud/bolt = around .020 of lifter plunger preload. In my experience.. 1 turn is too much preload and I always shoot for around 1/4 turn whether it be flat tappet or roller. Too much preload is valve standoff waiting to happen.
http://www.cranecams.com/uploads/instructions/453e_.pdf And yes, on an adjustable valvetrain I usually set the preload at about 3/8 turn. Tough to be that fine with a pedestal setup.
Pedestal rockers I just torque em down to 25 ft/lbs and forget about em Going by the "turns" would depend on the thread pitch.
Really ? Well you're mistaken. The pedestal rocker bolts are not the same thread pitch as the studs in the stud mount heads. Nice try at sarcasm, but you've struck out here.
Who said anything about stud mounts? 5.0s come from the factory with pedestal rockers. The OP is running iron Gt40 heads. That's what this discussion is about. If you want to just throw stuff together without paying attention to details, that's fine. That's what hacks do. And since you didn't have anything relevent to add to the thread I guess you're just trying to bump up your post count.
