BlwnLs1GTO

iTrader: (12)

I recently bought a set of new 317 casting heads CNC'd stock valve sizes.
I'm running the stock rockers with a brand new set of Patriot Gold .650 springs. Upon further inspection it looks like I'll need to shim some as the install height is out of wack as well.
I'm concerned with the difference in each valve though. Do you think I'll need adjustable rockers OR different length pushrods for each?
I put a level across the tops of each valve stem so you could see what I'm talking about.

I would really appreciate any and all advise as how I should handle this. Thank you.

hirdlej

iTrader: (31)

WOW, put the level down. You need a machinist striaght edge. You are in a totally different world using a regular level.

hirdlej

iTrader: (31)

BTW, who did the valve job?

bigdsz

iTrader: (1)

Some of the valves might be sunk a little deeper than others, shouldn't be a problem. Let me tell you what to watch out for though.

I have a set of Absolute Speed 5.3L heads that were about 5 years old and had about 40,000 miles on them. I took them to a performance machine shop recommended to me, for a valve job. When I picked up the heads the owner told me that he ground down and evened up all the tips of the stems and it would give me a few more horses. I was really pissed, because I thought the stem tips would have lost hardness.

That was the least of my problems. After I installed the heads and put the rockers on, I found that I had only .020- .025 clearance between the outer edge of the retainer and the bottom of the rocker. The spec is >.045.

I went to another head shop and the guy was surprised I found the problem. Long story short, I had new Ferrea valves installed.

Your lifters should take up the slack when you install the rockers. Just make sure you have 1 to 1 1/2 turns between zero lash and 22 ft/lbs torque. Also check the retainer clearance using a piece of wire that you have miked.

405HP_Z06

iTrader: (11)

This is a problem. You won't have consistent lifter preload with stock rockers.

BlwnLs1GTO

iTrader: (12)

Thanks for the replies.
How do you think I should handle this? Will adjustable rockers solve this problem? Or, would a couple sets of pushrods be okay?
I guess I need to know what to do with these now that I have the engine out of my car (Again). I really wanted to stay with the stock rockers and avoid spending any more money.

BTW
I bought these Brand New from a sponsor of this site.

RAGENZ28

iTrader: (5)

Send it back to where you bought the heads and tell them to put in new seats and actually measure the the depth when they cut

PREDATOR-Z

First you have to measure across the top correctly, the method you used is not 100% correct.
Get it done professionaly and if indeed they are different length, yes another valve job and perhaps new seats are in order.

vettenuts

iTrader: (4)

One other note, I agree with above the heads should be re-worked. The one rocker you have on looks like it is way too close to the intake side, i.e., the wipe is bad. If the valve stem heights are higher than stock, then stock rockers and the rocker bosses will need shims or other work to correct geometry. If these heads are new, I would personally send them back and look elsewhere.

BlwnLs1GTO

iTrader: (12)

Thank you for your comment.
I only put this level on so you guys could see the differences. It is noticable from the naked eye.
they are evenly offset one after another. ie: Intake valve is higher, and Exhaust is lower.

Old SStroker

I agree that you should discuss it with the Sponsor who sold you the heads before you try to fix it yourself. You might want to know how the valve tip heights compare to stock and why the intakes are so much higher tan the exhausts. They should have answers as well as solutions for you.

You could possibly shim the eintire stand and use different pushrod lengths on intake and exhaust but that is a lot of trouble and getting it correct is a challenge. What are the cam lift specs? HR I assume.

I like stock rockers because of their stiffness and light weight. I would work the valvetrain around them if possible.

Check with the supplier and let us all know what happens. It's good that you haved mentioned a name yet. Of course we are all taking our guesses as to who it is.

Jon

ss2668

iTrader: (21)

Im having the same problem. My exhaust valves are .034 higher than my intake valves. They are T.E.A 5.3 stg 1.5 heads
How did you fix your problem?

BlwnLs1GTO

iTrader: (12)

ss2668 brought this thread to my attention, sorry I never answered your questions, I surely appreciate your help.

The cam is a COMP XE-R .581/.592 224/230 114lsa

The supplier never ended up fixing the problem. They were POSITIVE that this was well within spec.

While I think it's worth mentioning, when I ordered the engine and heads over the phone, the 403ci shortblock was supposed to arrive with Diamond Pistons but came with ARIAS (-5cc I think)

BlwnLs1GTO

iTrader: (12)

I did'nt Fix the problem. I am running two sets of Pushrods on a set of Harland Sharp Non adjustable rockers.

I tried the stockers but they were a bit too loud for my taste. I bought a set of scorpion and everything was OUTSTANDING until they started to break.

If I were you, I would first try and get this sorted out with your supplier.
If not, I think you will be just fine to "Improvise" and find a good balance.

If you have a difference of .034 EVENLY Across, you can get away with 2-sizes of Pushrods. Assuming everything else is withing spec. Spring height, pressure, rocker swipe etc...

Both the HS and Scorpion bolt up to stock configuration and have an excellent geometry as well as price. The stockers with the HS bearing upgrade is always a good option too.