Here you got the pictures

red351 wrote:

Valve tip pattern looks good, but for some reason the top pic roller looks to close to inside edge Is there a way you can make adjustable longer push rod to just experiment with. The rocker angle looks steep also

I saw that too but I think the reason why is because its the next valve in from the outside and the photo is taken at a slight angle.

Nuther tip:  If you use the ARP 12 point studs you can re-torque the heads without having to mess with the valves/rockers.  Those studs take a 12 pt. 1/2...or is it 9/16" socket which will clear everything...much easier.   Just sayin'.

Also, don't forget to plug the secondary air ports at both ends of the heads.  Unless, of course, you are going to run the smog pump.

Oh oh....just looked again and it looks like you have studs with a smaller 6 point head...didn't have those available I guess when I did our's.

BB

Last edited by Bullet Bob (4/24/2016 10:26 AM)

The valve tip contact pattern looks good.  If you're under 0.500" lift I'm guessing you are going to have max engine speed of at most 6,500RPM, so the concerns over valvetrain geometry are considerably less than if you are trying to zing it to 7,500.  All looks good to me, and I've built quite a few street engines that had that exact contact pattern and never had rocker or valvetrain issues. 

TKO Performance - good point, it is also what I'm hoping for 

Personally, I think your pushrods are too short.  That rocker should be more perpendicular to the valve.  

Also make sure the rocker stud does not contact the rocker arm on the bottom during its range of motion. Sometimes you may have to elongate the slot in the bottom of the rocker, but usually if there is a high lift cam in the equation. Just a suggestion as who knows what the quality control is on the rocker arms and some may be close or contact the rocker stud, which can cause some serious failure if anything limits motion and will end up breaking.

The rockers I tested still had som clearance in the slot. It's just a pain in the a... to get a socket on the stud adjusting nut because the top edge of the rocker is close to the nut in the one end. Needed to grind som material of the socket.

My old stock rockers where rail rockers, and I tried one of those - the rocker angle is a little less steep, so they are a bit better in terms of geometry.
But it seems to me the issue is both in the rockers and the heads - the valve is a bit closer to the stud on those new FloTek heads.

Last edited by 69stangeu (4/24/2016 10:22 PM)

Marco wrote:

MachTJ wrote:

Also make sure the rocker stud does not contact the rocker arm on the bottom during its range of motion. Sometimes you may have to elongate the slot in the bottom of the rocker, but usually if there is a high lift cam in the equation. Just a suggestion as who knows what the quality control is on the rocker arms and some may be close or contact the rocker stud, which can cause some serious failure if anything limits motion and will end up breaking.

I agree with the opinion the pushrod are too short, and check for interference from rockers to rockers studs.
I arrive just from this experience that cause a lot of problems also to the valve guide and seat.

The short push rods (the one seen is adjusteble) are necssary for keeping the contact pattern on the valve stem in the middle to avoid guide and seat problems.

My only concern is the the pushrod to rocker contact, and rocker to stud wear. There is no interference issues.

Marco, I like to know more about your problems - was your experience only valve guide and seat issues ?
 

I second TKO in that the push rod length effects the location of the swipe of the rocker tip on the valve. If your rocker has enough rotation on the stud so nothing interferes and no part of the rocker touches anything else (like spring retainer) you should be good at 6800 rpm and below. And also as TKO said, I have only been able to reliably run to 8400 rpm with the shaft mounted rockers that are shimmed to close tolerances and are set up very accurately.

For what its worth, the rocker arm should be at 90 Degrees to the valve stem when the valve is half depressed.  For example, if you have .500 lift, at .250 lift, the rocker arm should form a perpendicular angle to the valve stem.  Even though the contact patch looks correct, from what I see, the push rod is too short.  As mentioned, the current position imparts a bit of lateral movement to the stem at initial opening.