valve adjustment problem help!

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buddyralf

buddyralf

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I purchased a set of roller rockers (Dove manufacturing) and a new set of pushrods for my 340. It is a hydraulic lifter with adjustable rocker and the pushrods are Comp Cam 7821-16 measuring 7.389" (recomended length)

The problem I measured the pushrod length on TDC #1 using the exhaust valve and saw the recomended length was good. Would the intake valve been different?

Now the pushrods are in, the rockers are in, the motor is at TDC and the valve lash adjustment chart (90 degree method) tell me to adjust #2 intake and #8 exhaust.
The problem, I have no slack. With the adjuster all the way off, the pushrod is tight. All the other pushrods are loose at TDC but #2, #8 are not adjustable at this point.

What happend? It seems the pushrods are too long. Did I measure incorectly?
 
All the other are good? Doesn't make sense....

When I built my motor I used a MP short block, Comp Cam & lifters, a set of Edelbrock heads, a Fel-Pro .063 gasket, and a set of Crane roller rockers. When I measured I needed a set of 7.00 push rods, which I had made by Smith Brothers. Everything adjusted nicely once together. 7.389 sounds like Magnum lenght pushrods.

Anybody out there have advice here?
 
all the others at TDC are loose but I think that is correct, its the ones I have to adjust that I cannot.
V8 273-360, 1964-86 Hyd. Cam w/ Adjustable Rockers #7821-16
 
check to make sure the pushrods seated in the lifter properly...sometimes they will get caught up on the side before they hit the center proper
 
I just had the same problem when installing rollers I started at a 1/4 turn to noisey went to a 1/2 turn and then a 3/4 turn and it all came together.Yes the number 8 exhaust was up against the rocker but finally settled in.I dont know maybe some lifters pump up and stay up along time. Just my experience.Kevin.
 
Have you tried this method?

Intake Valve Adjustment: ENGINE OFF!
with #1 cylinder Intake Valve at full valve lift .... Adjust #6 Intake Valve
with #8 cylinder Intake Valve at full valve lift .... Adjust #5 Intake Valve
with #4 cylinder Intake Valve at full valve lift .... Adjust #7 Intake Valve
with #3 cylinder Intake Valve at full valve lift .... Adjust #2 Intake Valve
with #6 cylinder Intake Valve at full valve lift .... Adjust #1 Intake Valve
with #5 cylinder Intake Valve at full valve lift .... Adjust #8 Intake Valve
with #7 cylinder Intake Valve at full valve lift .... Adjust #4 Intake Valve
with #2 cylinder Intake Valve at full valve lift .... Adjust #3 Intake Valve
Exhaust Valve Adjustment: ENGINE OFF!
You will notice that this is the same procedure and sequence as the intake valves listed above. Only now you are adjusting ONLY the exhaust valves the same way.
with #1 cylinder Exhaust Valve at full valve lift .... Adjust #6 Exhaust Valve
with #8 cylinder Exhaust Valve at full valve lift .... Adjust #5 Exhaust Valve
with #4 cylinder Exhaust Valve at full valve lift .... Adjust #7 Exhaust Valve
with #3 cylinder Exhaust Valve at full valve lift .... Adjust #2 Exhaust Valve
with #6 cylinder Exhaust Valve at full valve lift .... Adjust #1 Exhaust Valve
with #5 cylinder Exhaust Valve at full valve lift .... Adjust #8 Exhaust Valve
with #7 cylinder Exhaust Valve at full valve lift .... Adjust #4 Exhaust Valve
with #2 cylinder Exhaust Valve at full valve lift .... Adjust #3 Exhaust Valve

This is the way I do mine while using 1/4 turn before locking down and have no problems. It leaves 2 threads showing on bottom of the adjuster.
 
Did you just have a valve job? Whoever did the VJ may have sunk these two valves really deep.

Measure the installed height on these two valves and compare to the rest of your valves.
 
I am noticing that the pushrod is proper length on the #1 cylinder at TDC so I lenght should be right. The problem is the valve adjustment chart tells me that at TDC I should be adjusting #2 intake and #8 exhaust, but I think these are both fully open valves at #1 TDC. Should I not be setting the adjuster on the rocker when each cylinder is at TDC? No load like the #1 as when I measured the pushrod. I have never done this but it seems like something is wrong. All my pushrod adjusters are fully backed off, from what I know I am to tighten the adjuster till the pushrod has no spin, then give it 3/4" turn and lock it in.
 
These are the rockers

dart 006.jpg
 
Have you been able to see where the valve geometry is at through the open/ close of the valve? The reason I ask is because I had a similar problem with my rockers but I also had a higher lift cam installed. I had to shim up the rocker shaft to get the correct valve geometry and once I did that I was able to get the correct adjustment of the rockers. Before I shiimed the shaft my adjusters were almost all the way out and I still had a few push rods that were snug or not loose at all.

This may not be your situation but it took care of my tight push rods and also corrected my valve geometry.

Good luck!
 
This is the method I used and understood the best. It looks like it work great. It was my first time doing this, and I thought something was wrong. All is good in this department. Thank you for you help FABO

Adjusting Hydraulic Lifters for Proper Preload
In order to adjust the preload, the lifter must be properly located on the base circle or "Heel" of the lobe.
At this position the valve is closed and there is no lift taking place. You will need to watch the movement of the valves to determine which lifter is properly positioned for adjusting.
1. Remove the valve covers, and pick a cylinder that you are going to set the preload on.
2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe, the correct position for adjusting the intake.)
3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.)
4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at "Zero Lash". Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly.
5. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close. When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm.
6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again.
 
when you're at tdc take the dist cap off and see if the rotor is pointing at cylinder number 1. you're probably 360 degrees off of tdc.
 
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