120R Heads

[D-1]

I have a new set of standard 120R heads that were taken off a new engine when a Hurricane kit was fitted. Im fitting AV&V valve springs VSK675T to them and have found the intake retainers are flush with the tip of the intake valve. Im worried the rocker might contact them and damage occur. The valves are stock 120, havent been faced and the tips have not been ground.



The exhaust valves are as i would normally expect, the valve tip is proud of the retainers.



The stock 120R collets are counter bored (silver one in the picture), which would give some clearance around the valve tip. Does anyone know if the angle of the retainers and collets are the same? When the retainer is assembled on the valve with no spring, it feels solid on the collets and valve stem but thats not a very scientific test.

[wfolarry]

The keepers are not interchangeable. You have to use the AV&V keepers with their retainers.
The valve stem protrusion shouldn't be a problem. I use roller rockers with that much lift & you'll gain some clearance with them.
The counterbore is for lash caps.

[Don D]

I thought the ferrea hd valves had the same tip height intake and exhaust.
As larry said, the hd 10deg locks won't work. Also there are keepers available from PAC that will work with the AV&V retainers and they offer + or -.050 by moving the location of the lock groove. Check your spring pack height before doing this. Set them as recommended. You may be fine as-is if using roller rockers, as you should. Roll it over and observe.

[jsachs1]

I wouldn't worry. I use a lot of AV&V spring kits on Ferrea Valves (.205") tip with NO problems at all rolling off the tip. Roller Rockers, and non-roller rockers.
John

[kd]

I found on my 120R MVA heads, I had to position the rocker stand in their sweet spot to get dead on roller contact and pushrod clearance in the tubes.  I drilled the stands and pinned my rocker shafts (like a few others on this site) early on in the debate about rocker shaft noise. This was before the Rockout rocker lock went into production and became available.  l can also see how using them will make it impossible to tune the location  of rocker arm or roller contact point on the valve tip.

[D-1]

Thanks for the replys. I will mock it up with light springs and see where the roller contacts.

[kd]

Remember, if you are not using rocker shaft locker sleeves in the rocker stands you can shift them slightly to adjust the valve tip contact point.  That will also change the centering of the pushrod in the tube so it's best to do installed.  You can then turn the engine over slowly and watch the contact point throughout the arc while making sure the pushrod doesn't contact the tube.  It's also best to bore the top pushrod tube while you have them off to 5/8 inch about 1 1/2 inches deep.  The pushrod tube bore job is good to do (to increase available clearance) no matter what you are doing.

[D-1]

With roller rockers installed and a light spring i can see the roller is very close to the locks. All i need is 0.010 off the top of the locks and it will be good. It wont be hard to linish the locks a small amount, and i cant see any reasons why it would affect their operation.

The height from the top of the lock groove to the valve tip is approx 0.200 on the exhaust and 0.160 on the intakes. The old intake valve is 0.200, so there was a change along the line somewhere.