My1968Vette

I did a valve adjustment to all valves. after about 20 minutes they seemed to be loose again. is this normal? i figured i will do another one when engine has run for a little bit. do i need to go back and do this again before i run it. thanks

Doug1

how did you do it? I'm not good enough to go by "feel", I need a feeler gauge myself. how does it run, good power? no spitting up through carb? smooth idle? quiet when engine is running?

My1968Vette

not sure yet. haven't started it yet. will let ya know when i do.

Doug1

when you adjusted the first time, how? feeler gauge? did you do intake just as the exhaust began to open and the exhaust and the intake just closed?

oldalaskaman

like most ...older folks , I had my version of valve adjustment that I used for years...and years, swore by it, never failed to work, told others how to do it, argued about it being the best way, Got member "lars" paper on adjusting valves, tried it, I'll never do it any other way. right on the money, put the valve covers on and forget about them. no mess, no worry. I was pleasantly surprised and very happy. Thats one job that I knew had to be done right, my way worked great, but "lars' was light years better.
ask for his papers
v8fastcars@msn.com

My1968Vette

i followed the manual. seemed to be ok. just wanted to make sure i don't have to do this again. i read the paper on lars. only problem i have is the four corners. this is a huge pain in the *** due to the front of the motor all on and really no place for me do do all this without a lift. the paper is great and recommend everyone to read. i guess i'll just start it this weekend and hope for the best.

johnt365

I still have the marks on my balancer from using that method but if the motor is together, I agree it would be hard to do.

As a last resort, you could go old school and adjust them with the car running. If you have an old valve cover laying around you can cut a slot in it to help keep oil from splashing everywhere. I have been know to bend up some cardboard as a shield. You gotta be fast if you do it this way or you will have a mess.

Loosen each valve till you hear it clatter, tighten it till it gets quiet, then give it an extra 1/2 to 3/4 turn.

Indiancreek

Loosen each valve till you hear it clatter, tighten it till it gets quiet, then give it an extra 1/2 to 3/4 turn.[/QUOTE]



If you are running stamped steel rockers/ factory rockers, there are snap on plugs that your parts store should have that stops the oil stream from the rockers during a running adjustment.

cv67

If its a hydraulic cam they may not seem "right" til its running and you have oil pressure. If you put your preload on when there was no up/down slack in the pushrod they should be fine.
"spinning them" sometimes works sometimes doesnt. They can still spin as the plunger gets pushed down in the lifter it can throw you off.

garygnu

is it a solid or hydraulic cam ?hydraulic lifters bleed down quickly.I use a drill and prime the oil system for each valve setting.what kind of nuts do you have for the rocker arms ?do they have set screws ?

leadfoot4

FINALLY, somebody asked question number 1.....

wheatpj

Same thing happened with my LS5. I ran the engine, then adjusted the values...by the time I was done the first lifters were loose. I assumed that some of the pressure bled off the lifters. I didn't go back and re-adjust because I figured I'd be chasing my tail adjusting and re-adjusting. I runs fine.

bigvette1

Two things come up in this discussion
1. If you adjust when warm you set preload at a specific point with oil in the lifter. As they cool the oil bleeds off and they start to loosen up. I prefer to do them cold when all bleed down has finished.

2. On rockers without the trunion or allen set screw the rocker nuts have about 1-2 adjustments in them and the nylon "locknut" material starts to compress. After heating and cooling they will loosen up causing misadjustment. Your solution to this is adjust and use at least 3/4's after zero and it should be ok for a long time, or replace.

racegofast

no kidding

MotorHead

After cold adjustment some will be still be loose depending on where they are sitting on the cam.

2) You can get rocker nuts where the top threads were originally purposely deformed in order to make them "not round" and grip the stud threads to make it a self-locking nut.

This make them hard to turn and hard to back off on there own. This type seems to last longer.

And once again a cold engine no matter what type of lifter hydraulic, solid roller, whathaveyou will have some loose after they are adjusted.

And cut a slot in an old valve cover to adjust them running

leadfoot4

"Nylock" nuts are NOT the proper adjusting nut for use in an engine. As "Motorhead" mentioned in his post, there are special nuts used, that have the top 3-4 threads purposely deformed to cause them to "lock" on the rocker arm studs, and hold their adjustment.

Dino_'72

Do we know yet. Solid of Hydraulic?

leadfoot4

NO!

......yet the "instructions" on how to do it, keep flowing!

Doug1

my father in law loaned me a cool tool, by snap on. connect it to starter, lets you bump the starter with a switch you hold in your hand as you observe the valves and adjust accordingly. made it very simple

leadfoot4

This thread is getting pretty funny.

Going into the third day, and the OP is gone, he never stated whether he had a solid lifter cam or a hydraulic lifter cam, but we got all sorts of ways to adjust it....