ok, I replaced all of the valve seals and thats what started this whole thing. Then after removing the pushrod lash by spinning the rod and then adding 1 full turn I had backfire thru the carb big time.

So today I opened up the valve covers, removed all the spark plugs, got the crank at TDC on #1 and put 50lbs of shop air into the spark plug hole. This way I could hear when the valve was coming off it's seat.

So, start fresh, back out the rocker nut all the way, bring it in until the push rod has no "play" (not by turning the rod but by no up/down lash)
now... shop air on..no leaks except a little from the rings but not much at all. turn the nut until the valve comes off it's seat.... 1/4 turn

1/4 turn and the valve opens... both respond like this on #1 cylinder

So the 1/4 turn I put in all went to the valve spring and none went to "load" the lifter.

I was really surprised to get the valve off at just 1/4 turn.

When I look into the block the lifter does not look collapsed but I cant tell for sure cause I am looking straight down on it.

ANY suggestions would be a big help cause I dont want to go any further just in case all the lifters have to come out...all things considered the intake and distributor are not a big deal at this point.

 

I am not that much of an expert but I believe that you should have loaded the lifter...the manual calls for 1/2 or 1 turn after "zero play" - definately more than 1/4 turn... your valve should still be closed after that 1/4 turn...

Lifters are cheap, if you suspect them to be bad, then replace them....it's less pain than having it to do all over again ... just my 2 cents....

This symptom might be normal for solid lifters ???

 

1. Are you sure these are not solid lifters?

2. Have you checked your spring pressure? If you have a week spring it is not hard to unseat the valve.

3. Also you can bring the engine to TDC (MAKING SURE BOTH INTAKE AND EXHAUST LIFTERS ARE ON THE BASE OF THE CAM CIRCLE) take off both rocker arms and push down toward the lifter on both push rods. Look to see if one appears shorter than the other.

Hope this helps.

Steve

 

1) yes, they are stock hydralic lifters, not roller or solid.
2) valve spring pressure was not checked, all I wanted to do was replace the oil seal cause it was burning blue smoke when cold for a few minutes.
3) I am sure I am at TDC on #1, 100% sure, remove both rocker arm and push down on the push rod. They dont move at all. dont go down at all. I am sure I have the pushrod in the lifter "cup". the lifter cup seems to be up at the top of the lifter itself but like i said it is really hard to tell from my point of view. The both appear to be the same length when seated in the lifter cup.

??

 

Where is the distributor pointing, if it pointing at the firewall then you are on overlap on #1 and firing on #6 this would explain the problem your having

 

the rotor is pointing to the firewall yes, right under wire #1
How can I be firing #6 in this position ?

 

Sure seems like solid lifters to me. I just came back from the shop and just out of curiosity I pulled a valve cover and attempted to preload my solid lifter as you would a hydraulic lifter. My results were the same as yours, about a quarter turn and the valve comes unseated. Short of pulling the intake there's not much else I can think of to do. Let me know what you decide to do and how everything turns out.

 

I think motor head was refering to timing being 180 degrees out. I think he may have just looked at the backfiring through the carb part and not the issue with the lifter/valves.

 

Normally your rotor should be pointing towards the rad when firing number 1 cylinder.

The balancer has to spin twice for all 8 cylinders to fire, the zero timing mark will tell you TDC on power stroke for number 1 cylinder and the next time it comes around it will be TDC on power stroke for cylinder number 6.

Two cylinders will always get to TDC at the same time, one will be firing and the other will be halfway between the exhaust and intake stroke ( overlap ) and will not be on the base of the cam at this point. If you try and adjust the valves here they will not be right