Rocker Arm nuts Driving me INSANE!! HELP

[forestguy]

I will say sorry right up front, but this might get a little long. My valve train has been getting louder over the past 6 months. I thought it was a couple of bad lifters. I stsarted yesterday taking things apart. Once I got the valve covers off, I noticed several of the rocker arms were very loose. I got excited, now I don't have to worry about the lifters if the rockers are the source of the noise.

So, I followed the Haynes book and tightened all rocker arm nuts to 17-23 ft. pounds. I hand to turn all of them a lot to get 17 ft. lbs. I put the covers back on thinking this was the fix and tried to fire the motor. The motor turned over with no resistance. I now had no compression. Now I am getting frusturated.

I then took the valve covers back off and backed off the nuts untill I could move the rocked slightly. She fired back up no problem. Now I had all the rockes making noise. I thought I will just tighten them up to 10ft. lbs. while the engine is running. This made the engine not want to idle and even pop back through the carb. I got pissed at this point and called it a night.

Talking to some buddies, I have decided to back off the rocker nuts one at a time untill they start to "click" and then tighen them one full turn the point of no noise. Will this work.

One more thing everyone should now. I have no idea what cam and push-rods are in this engine. I was "professionally rebuilt" shortly before I got it.

Thanks in advance, and sorry for the long post.
Rodd

 

[elemetal]

Sounds like tightening the rockers is causing the valves to not retract all the way. Are they the standard non-adjustable type? It almost sounds like you've got adjustables ones and the lower locknut moved on you.

 

[SeaBiscuit68]

Did you do them in the proper sequence?

 

[forestguy]

I don't have nuts under the rockers.




I did not tighten them in any particular order. THe book just says to tighten. I thought there might be some order.

 

[elemetal]

Check the book but I'm pretty sure you do 'em when the valve is completely seated (rocker is not compressing valve spring). You're lucky you didn't blow fire up through your intake.

 

[SeaBiscuit68]

I don't have my book in front of me but some are done at 0* then some at 180* and the last ones at 270*. Maybe you're looking at the wrong page?

 

[mustangmarty]

It sounds to me like you have adjustable rockers. If I remember right, you have to tighten them down only when the that particular valve is completely closed. You have to slowly twist the pushrod between your thumb and finger while tightening the main nut until you feel slight resistance. Then tighten down the lock nut. You have to turn the engine by hand as you go to each rocker to get that particular valve shut before tightening it. It's a pain in the arse, but it's the best way I know how to do it.

 

[broncnaz]

Sounds like adjustable rockers to me also you can check it by pulling 1 rocker arm then put the fulcrum back on if it slides to the bottom of the stud you have adjustable rockers if the fulcrun stops before reaching the bottom than you have non adjustable type and it shouldnt matter once they are torqued down as they go down that far no matter what and will not change the clearance. thats why I think you have adjustable rockers which will not torque down until everything is bottomed out. If you have adjustable rockers its possible that the nuts need to be replaced some positive lock types with a set screw in the center are better than the stock types.

 

[forestguy]

Here is a pic.

 

[forestguy]

I will pull a rocker and see if the fulcrum slides all the way down.

 

[forestguy]

Fulcrum slides all the way to the bottom of the stud. What is the procedure for adjusting this type of valves?

 

[forestguy]

Here are some pictures of the fulcrum and rocker. THere is some visable wear on them. I wonder if I should just replace the rockers, fulcerums and nuts.

 

[forestguy]

I found this at summit.

 

[forestguy]

Sorry hit the button too soon.

 

[HotWheels]

In both my books it also says just to torque to 17-25 ft lbs on the 303, 351, w.

It says there is a sequence for the 400m and such...not the 302...351.

I'm at the same place.

 

[forestguy]

there is a differance in the adjustable and non-adjustable. I have adj. and I think you have non.

The way I see it is, for the adjustable rockers, the valve has to be closed, and then tighten the rocker nut untill you start to fell resistance on the push-rods.

This is going to be a pain in the arse!

 

[HotWheels]

my fulcrum goes all the way down on the shaft also. I am still going to do the 0-180-360 torqe to 25ft lbs. what can it hurt? nada.I'm using a remote starter to "bump" the engine over.

 

[mitzel]

I don't know how to determine adjustable vs. postive stop from viewing
the top of the rocker arms in your picture. what I did get from the
picture:
- there's a '65' in the head casting.
- you can sorta see the pushrod hole of the rocker at the right end of
the picture. to me it looks slotted/rectangular shaped rather than
round.
I believe what you have there is a pre 65-1/2 289 head. from the
factory those would use fully adjustable, pushrod guided (non-rail)
rockers.

of course over time the rocker arm studs and rockers could have been
modified. a way to determine adjustable vs. positive stop is to look at
the rocker arm stud. fully adjustable uses a 3/8" stud pressed into
the head and the threaded portion is 3/8"-24. positive stop uses a 3/8"
stud pressed into the head and then it necks down to 5/16"-24 in the
threaded portion. the procedure that broncnaz suggested is basically
checking whether there's that shoulder present where the stud necks
down from 3/8" to 5/16".

so it sounds to me like you determined you do have adjustable rockers.
I would think your tuneup book should cover that procedure? basic
procedure as other have mentioned is you need to turn the crank to
get each lifter on the base circle of the cam, adjust the rocker down
to zero lash, then tighten 1/4 to 3/4 turn past zero lash. in order to
avoid turning the crank like 50 times there's a procedure SeaBiscuit68
aluded to where you start with no.1 cylinder at TDC (end of compression
stroke) adjust 6 valves at that position, turn 180 degrees adjust 4 valves,
then turn 270degrees and adjust last 6 valves. I know the monroe rebuild
book covers that and probably other tuneup books describe it to. the
driveway method of running the engine, backing off the rocker until it
starts slapping, then tightening 1/4 to 3/4 turn is a bit messy but highly
effective too.


good luck! danny

 

[forestguy]

I think you have hit the nail on the hear mitel!!! They are 3/8 by 24 threads about hlaf way down the stud. I went to summit racing and got some positive locking nuts to re-install on the rockers. I don't want to have to do this again any time soon. I have already made a huge mess, so I am going to do it running this time.

Everyone wish me luck, I will pray to the almighty beer gods and get this done. Then it will be beer O' clock.

 

[elemetal]

I may have mis-understood your last post but you're going to do a rocker adjustment with the engine running? Bad idea, if I read it right.