Heres a few more pics from my nice camera.. I think the closest you can see a rocker getting to the stud is when it goes under lift...

 

So these latest pics only prove that the rockers are sitting on the stud shoulders. So get rid of the guide plates and get SA rockers.

 

don't think iv ever heard someone suggest going from NSA with guide plates to SA rockers.

 

I relashed the valves AGAIN, and started it.. its just like it has been, it runs fine and theres no valve train noise or ticks or anything! Im letting it cool off then im going to take a peek at the rockers.. I needed to test my MAF and FPR.

Heres a video of the car, its pretty much untuned and missing loads of sensors.. but it runs pretty well apart from this rocker issue..

take three - YouTube

 

There are probably thousands of us running guideplates and non-SA rockers the guideplates and rockers can work if he figures out why the rocker is hitting the stud.
Your "solution" amounts to throwing the baby out with the bathwater.
OP did you maybe get a small base circle cam? If so then I would expect to need longer pushrods, wouldn't expect .200 longer but longer.

The pics of geometry don't really help me I am one of those guys who does better seeing in person.

 

I am just throwing this out there ... 1 of 3 times to Advance Auto Parts - they try to give me the wrong ****.

I would pull the failing components, as well as one "good" lifter/valve combo and critically compare. Look at part numbers (if stamped), measure with calipers/micrometers, and question where you got the camshaft from? If it is a small base circle camshaft it could do that. If someone went completely ****ing wild with your heads or decking your block, it still shouldn't need 7.4" rods. This is literally, almost a 1/4" material that would have been removed. If that was the case, the compression would be diesel-like.

Please, really, update this thread as you figure this one out as a lot of us are genuinely interested in the problem/solution.




Joe

 

Most likely the aftermarket Trickflow heads you are using have taller valves to allow for higher installed spring heights, thus allowing more valve lift before coil bind. It is not unusual to see aftermarket heads like this set up to handle .650"/.680"+ valve lifts. If this is the case going to a 7.400" push rod will move the rocker considerably higher "up' the rocker stud, by using the taller valve location as a "pivot" point. Got it?

Before you do anything else however, re-adjust your valves taking GREAT care to insure each lifter is on your cam's base circle when determining zero lash, and, after adjusting ALL your valves this way ......... take a careful look at how high the locking allen screws are above the hex huts on all your now freshly adjusted rockers.

Are ALL the allen screws at the SAME height above the hex nuts when locked?????? If they aren't ....... you have either lifter problems, or bent pushrods. (This assumes, of course that you DO have all the trunions installed with the hex nut retaining groove facing "up").

If there is any varience in the locking allen screw to hex nut distances ........ see if it conincides with those rockers that are hitting the stud ......... you should then find collapsed lifters, or bent pushrods associated with those rockers.

 

I agree, its probably got to do with my trickflow heads as they are pretty new not many people are running them, and like you said it probably has taller valves and in addition, The cam circle base my friend said is most likely smaller, I do have the cam card but its very faded.. its a LE cam he ground for my setup..

I pulled all the allen screws out today, relashed and installed.. all the allens screws are pretty much the same height.

i'll update some more findings tomorrow.

 

If you ARE using a smaller (i.e. reduced), base circle cam grind ....... you WILL need longer pushrods to compensate for the lifters riding lower in the lifter bores.

 

Yeah, Theres a good chance it is a smaller circle base, its not a crazy cam but it does have .592/.592 lift.

 

I had a similar issue with 23* Trickflow heads and ended up adding a large radius to the bottom of the rocker arm. Mine were slightly interferring with some of the cylinder head studs.

 

Desired rocker tip sweep should be the one that is narrowest, which is not always the one that is perfectly centered, it's perfectly possible to have a sweep pattern perfectly centered but to have a .150" wide sweep which is way wrong. You should end up at ~.060-.080" of sweep across the valve, and from the blurry picture it looks like you are quite a bit wider than that. You need to try some longer push rod lengths and measure the sweep because the rockers are hitting the studs due to them sitting too low. If you cannot put in a longer push rod to raise the rocker and still have a good sweep pattern, then you may be able to effectively raise the valve tip height by using lash caps and then going to a longer push rod. I see no reason though why this out of the box head shouldn't work with one of the most common rockers out there, so my assumption would be that your push rod length is too short.

Ideally, if the geometry ended up all being correct, then the permanent fix would be to mill the rocker pedestal down.

 

My cam is a small base circle, that coupled with the taller valve stems will easily add 1/4" to pr length if block has not been decked and heads have not been milled much. Small base circle cam is common with stroker motors for more rotating assembly clearance. I could imagine trick flow heads without taller valves.

 

If you break it down and look at it as maybe .1 from the base circle and .1 from taller valves and then it would seem within reason for the Trickflow rocker bosses to be a little taller to make room for the larger port then 7.400 does begin to seem reasonable. The first time I posted asking about a small base circle I hadn't thought about longer valves.

 

I have 23* Trickflow heads, and the valves are not taller. MachinistOne was correct about the geometry. You do not want the most centered pattern, you want the narrowest sweep. It does not matter if the sweep is favors the intake, or exhaust side more. Whatever is narrowest is where it should be. I'd check at 7.25, 7.3, and 7.35 to start. Mid lift is another way to check geometry..

Here is a good read: Rocker Arm & Valve Train Geometry - Circle Track Magazine