Pred 212 Valve, Pushrod, Roller question

[Griff]

Okay so 308 cam, .230" longer valves, 32# springs, and if I recall the pushrods are just a hair over 5" (like 5.02").. I do have a valve cover spacer in case someone mentions it lol.

From the ports it doesn't show that I'm even close to hitting the piston. But the springs do coil up real tight. Not quite binding, right? Should I cut my pushrods? There's no room for lash caps, or even lashing at all.

Thoughts and advice?

Here are the pictures:

 

[bob58o]

Valve train Geometry is not my strongest area.
Guessing those are the 1.2 Roller Rockers for the Hemi?

http://www.nrracing.com/product-p/headhemi.htm

Hemi heads are prone to piston to valve clearance. They must be checked carefully
Hemi heads are subject to coil bind using .070" Valves
We do not recommend 1.3 rockers due to valve to piston clearance issues.
The .230" valves may create improper valve geometry when using 1.2 or 1.3 ratio rockers
1.3 ratio rockers may coil bind when using .070" valves
.274 and 1.2 Rockers are max recommended valve lift for .070" long valves



I've never used Ratio Rockers.
The NR site makes it seem if you want Ratio Rockers on a Hemi head and proper Valve Geometry, you need the +0.070" Valves, not the +0.230" valves. Also with the 1.2 Rockers and +0.070" valves, a 0.275" lift cam is the max they recommend (using the shorter valves).

 

[Griff]

So stock rockers??? Why does that seem bad? I think cause money has gone into replacing almost everything else in the valve train.

 

[bob58o]

https://www.nrracing.com/product-p/cmpr-55.htm


212 Predators (Hemi Head)
5.544 Stock Length, most applications
5.440 (-.100) use with extensive milling
5.260 use with NR Racing Hemi Rollers
5.160 use with NR Racing Hemi Rollers and heads milled .065 or more, also with large base circle cams.

Also available in unfinished. Must be cut to length. Includes tube and two ends

All push rods are sold individually.

Note: Due to differences in cam base circles, deck heights, head milling, gasket thickness, etc. actual push rod length can vary. Pushrods are sold for the experienced engine builder.

We recommend you assemble the motor first and then determine correct pushrod length. One of the best ways is to grind a stock pushrod until you get correct geometry, measure, and order one closest to that size.

I don't remember exactly what is covered in this video. It may be 90 minutes that don't help you, but I know there is good info here,
https://www.youtube.com/watch?v=ISU-36-9eLw

---------- Post added at 02:02 PM ---------- Previous post was at 01:56 PM ----------

So stock rockers??? Why does that seem bad? I think cause money has gone into replacing almost everything else in the valve train.

Well the biggest issue is you loose the lift the and the rate at which the valve opens (which is why most people go for ratio rockers). I have spoken with Jody at ARC and he said he has never seen a stock Hemi rocker fail - as long as the valve spring was not coil-binding.

I have also never used the +0.230" valves so I don't have any personal experience with those. Russel at NR isn't easy to get on the Phone either. BUT it is possible to get a hold of him. I might try calling him a few times.

You CAN get somebody at ARC on the phone anytime you want, but I'm not sure they sell the parts in question, so even though they could probably help you - not sure calling them about another product is cool.?

 

[KartFab]

One of the arc videos goes over coil bind clearance. I think you stick a .060" feeler gauge in between springs. If it fits you don't get the bind at max lift.

I use an adjustable Push rod from nr racing to get my geometry right, then cut my own rods.