Shadygrady

iTrader: (3)

I`ve been having a problem snapping rocker studs off inside the pollylock.Ive searched and found people with the same problem.It seems the polly lock isnt going down far enough on the rocker stud,and the set screw is far down inside the polly lock when its tight on the stud.I`ve seen pictures posted and people bought longer rocker stud.It gave the polly lock more stud to grab and the set screw was up higher at the top of the polly lock.Ive posted before and searched and learned I needed to check the valve train geomotry.I bought a pushrod length checker and checked it with the guy who helped me build the engine.He said it looked good and I saw that it did roll over near the center of the valve tip like the comp cams site says it should.He sugested we could go with .002 shorter pushrods or so.I told him about the 2/3 method I`ve read about on here in my searches.We looked at it again and it kinda falls in between the two.My question is which should I get longer studs or shorter pushrods?This wont change lift either way will it?Anyone with any experience with this problem please chim in.Also when we took the rocker arms off it seems several have needle bearings freezing up on them with metal flakes coming out of them which explains why I had small amounts of metal flakes on my magnetic drain plug.Did the rockers being in a bind cause the needle bearings to go or is it just cause the cat stainless steel rocker arms are crap.I am getting new rocker arms.Btw my zz4 heads came set up for a zz4 cam with lt4 springs and retainers(up to .525 lift) and I am running hardened pushrods(7.2) with isky adjustable guid plates,7/16 studs.Lt4 production cam w/ 1.6 rockers lift .476/.480.Sorry for long post just trying to get to the bottom of this.thanks

Sonix

iTrader: (1)

Get longer studs to start. If the contact pattern looks ok, then your pushrod length is fine.
If the rockers were binding, that might have caused the rocker studs to snap off as well. Get new studs, then recheck your pushrod length. .002 longer doesn't make any sense... What length were you thinking you needed?

Shadygrady

iTrader: (3)

Thats what I was thinking just trying to get other opinions and feedback.Oh,and I said .002 shorter.I think thats two thousanths.

Sonix

iTrader: (1)

Yea, .002" is nothing. That's measurement error right there. When you buy a set they're probably +/-.005" at least, going through all 16 of them.
You can only buy them in .050" increments, maybe exact lengths if you wanted to pay to have a custom set made. (But for an SBC there isn't much you can do that hasn't been done before so off the shelf ones should be fine).

Shadygrady

iTrader: (3)

my bad I knew you could buy them in .05 increments.The measurement I had in mind was 7" pushrods and I `m running 7.2.One too many zeros there.I`m gonna try the longer studs first.I`ve seen studs that are 1.6,1.75 and 1.9 any idea what length to use.thanks

Sonix

iTrader: (1)

That's what I figured you meant, I just wanted to make sure we're on the same page

I'm not sure what rocker studs you have now, so you may as well remove one and measure it, then go one size up. :shrug: