Welcome to the Corvette Forums at the Corvette Action Center!

Should rocker arms be loose

S

Shadowing1985v

Guest
let me make sure i understand this chart

from top to bottom

does that follow firing order?

or what
 

Twin_Turbo

Well-known member
Joined
Jan 11, 2001
Messages
618
Location
Enschede, The Netherlands
Corvette
1982 Twin Turbocharged Red/Black
No, you just start at TDC and work your way down the chart, can't go wrong

You need to devide the dampener in 8 equal 45 degree increments. Check no1 TDC with a TDC check tool, do not rely on the dampener as the outer ring is known to slip

Marck
 

jeepie

Well-known member
Joined
Feb 6, 2002
Messages
162
Location
Dunmore, Pa.
Corvette
1991 Coupe Blk/Blk
Its been a while since I built an engine but I remember setting at #1 tdc and there is a list of the valves you can adjust (half) then turn the engine 180 degrees and adjust the other half. If I remember correctly it was in a chiltons maual. Although it has been a while and I have killed many brain cells since then. But I remember it was pretty easy to do.
Good luck.
 

Twin_Turbo

Well-known member
Joined
Jan 11, 2001
Messages
618
Location
Enschede, The Netherlands
Corvette
1982 Twin Turbocharged Red/Black
The chiltons way works as well as other methods but the list I posted lets you adjust all the valves with a minimum amount of rotations so that when you install a new cam you don't run the risk of wiping off the break in lube

Marck
 
S

Shadowing1985v

Guest
why can't i just do this

put carboard around my intake

take the covers off,,, or get one of those one covers that my friend does have

start the engine with all nuts lose and just slowly tighten them
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
WHAT'S THAT SAYING!!!!!

... YOU CAN LEAD A HORSE TO WATER!!!!?????
 
S

Shadowing1985v

Guest
No

im saying which way is the most accurate way
 

Topless

Well-known member
Joined
Nov 12, 2001
Messages
444
Location
San Diego, CA
Corvette
1992 Convt w/hard top; 2004 Z06 Z16; 1962 327/300
Is that adjustment order good for every SBC? Solid and Hydrolic lifters?

Yes, you can do it with the engine running, I have done it on another SBC. It is a quick and dirty way of doing it. The question is really, "How accurate do you wish to be?"

-Mike
 
S

Shadowing1985v

Guest
o is it really that dirty

hmm,,, maybe i should do it this othe way
 

BigRed

Well-known member
Joined
May 23, 2001
Messages
948
Location
Edmonton
Corvette
1985 Bright Red Rocket
You know Ive been watching this thread with interest (I copyed the table hope you don't mind) But theres two areas of the engine Im still learning thats Heads/Cam and Distribution.

Id like to rebuild or upgrade my engine someday but I sure as hell don't want to go in there blind folded.

My quick questions are, If I buy say Edelbrock performer PREbuilt heads can I simply "drop" them on then torque the heads bolts properly? Or is there a WHOLE procedure with this?

Also if I change cams do I have to change pushrod or simply loosen the rockers? And last one On roller rockers people keep telling me theres no acurate way of setting (Torque meter wise) except for doing the spinning pushrod rule, Is that correct?

Thanks
 

Twin_Turbo

Well-known member
Joined
Jan 11, 2001
Messages
618
Location
Enschede, The Netherlands
Corvette
1982 Twin Turbocharged Red/Black
If you buy new heads you can slap them on but that is nopt very wise. Proper practise is to check everything. Someone at edelbrock could have been sleeping or somethin and really screwed up. Check all spring installed heights and if you have the tool, seat pressure. Also check if the heads are absolutely spotlessly clean. It wouldn't be the 1st time chavings & stuff still remained somewhere on the heads.

If you change cams you must take out the pushrods & lifters, with no cam the lifters will fall down into the engine. Only the roller rockers w/ crossbar & spring can be changed by loosening the rockers (the springs will press them up).

If you're going to run guide plates (they usually come /w the heads) you must run hardened pushrods (unless you have those plastic guideplates)

On hydr. lifters the spinning pushrod method is about the most accurate way. You can also do it w/ feeler gauges and bottoming out the lifter (valve wills tay open...can be heard w/ engine running) but it's kind of tricky to do it like that (one benefit is you can set all the hydr. lifters so that they are depressed by a great deal and have just enough free play in them to take up vibrations in the valvetrain but not to loose lift on upgoing ramp by depressing)

Marck
 

BigRed

Well-known member
Joined
May 23, 2001
Messages
948
Location
Edmonton
Corvette
1985 Bright Red Rocket
Hey Im always up for a new tool :L

I was just running through my Jegs catalog! Feelers,Valve spring compressors,Lash wrenches all for about 150 Bucks. So when I do my heads I'll pick these up also.

But I can't guarantee that I won't be posting like a banshee when its time LOL. :L
 

billd

Well-known member
Joined
Dec 9, 2001
Messages
88
Location
Denver,CO
Corvette
2001 red convertible, 1985 wht
I tried the spining method

I set my rockers up last week tried that spinning the pushrod method. THREE times finally I gave up and on the advice of many small block chevy lovers just set it while it was running. No special covers no cardboard. Just pulled the valve covers and turned the nuts until the noise was gone. Since these are supposd to be zero backlash It was very easy to do. Those spcial covers you were you were talking about are more to keep the mess to a minimum than anything but I found that it really wasn't that bad and if you can deal with a little smoke off the top of your manifolds for a short time this is an excellent way to accomplish what you are after.

Also if the rocker arms felt loose but you werent getting any lifter noise there was probably nothing wrong with the adjustment.
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
I put this in another post regarding hydraulic valve adjustment. It is also appropriate here.

There are two ways to do this in my opinion. One, cold set method. You pull both covers. Rotate the engine to #1 TDC at the compression stroke. If you have any g.m. or equal manual, it will take you through a series of the valves that are dead closed at that point (8 at a time). I like to back off the nut, spin the push rod with my fingers, and slowly tighten the nut. When I feel the pushrod get tight where I can't just spin it, I try to wiggle up and down. If no wiggle, then I go 3/4 additional turn. The G.M. manual will suggest up to 1.5 turns after zero lash. Then you rotate the engine 180 degrees, and do the other set of 8. I don't have time here and now to look it up and post the list of valves intake/exhaust that you can adjust at the rotation of TDC, and 180 from TDC. I trust you can look that up for yourself. This is my prefered method, and works great for me 99% of the time. DON'T ATTEMPT "ZERO" LASH ON A HYDRAULIC SYSTEM, AS THEY WILL RATTLE AND CLICK WHEN THE ENGINE IS COLD AND OR AFTER THE OIL HAS HEATED UP AND THINNED DOWN. YOU MUST GIVE THEM AT LEAST 1/2 TURN AFTER YOU HIT THE "ZERO" MARK.

Second method is most likely more accurate for a worn engine. Pull both covers. Get some tin foil and fashion little squares about 2"x3" or so, and make them so they can form over the top of the rocker arms (like a little molded hat). Fire up the engine (make sure she is warmed up). One by one, remove the little hat (the hats keep the oil from getting all over the engine bay), and back off the nut until you hear it clicking. Then, tighten slowly until the click stops, then go 3/4 additional turn. Put the little hat back on that one and move on to the next. The order means nothing when choosing this method, just as long as you get them all. You might have to start and stop several times to avoid the engine just running with no valve covers while you are setting up for the next valve.
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Chris

I prefer your second method when I set up my engines... but I have gone 1/2 turn not 3/4... but I typically run thicker oils (20-50 GTX)

I KNOW scientificaly that 10-30 is fine but living in CA..... I cannot put the thinner stuff in, call it paranoia...... but it my level of comfort!

And I build cruisers... not rickie racers.....


Vig!
 
S

Shadowing1985v

Guest
ok guy's,, im done

i adjusted them while the engine was running


have 0 noise now
it was idling at 530

i never put it in drive to see if it drops to 400
like it should

i'll tell u guy's tomrorow..
 

trackitman

Active member
Joined
May 11, 2002
Messages
44
Location
Lake Orion, MI, USA
Corvette
1992 Convertible White 6 sp
1/2 way done

I've been following this thread also. I adjusted the passenger side this afternoon with the running method. Had a couple of noisy rockers that are now quiet. I used the foil method to keep oil off the manafold, worked pretty well, thanks.

I eyed the drivers side, it seems to me the bracket for the a/c and alternator is in the way to get the rocker cover off. Anyone know if it comes off easy? The passenger side was a pain because of the exhaust recycle pipe. I could only guess the drivers side is difficult also.

Thanks.
 

WhalePirot

Well-known member
Joined
May 9, 2002
Messages
2,942
Location
SoCA
Corvette
1984 White Z-51/ZF6-40/Shinoda body
Running works for me

Those foils 'hats' are a great tip, in place of the oil stopper clips. I have also used cardboard, edge down below the springs, settled into the channel just inside where the valve cover seats. I also like the spinning rod technique, but it requires some dexterity.

Chiltons: "Normalize engine temp by running it for about 20 minutes. remove valve covers. Install clips (hats). For hydraulic lifters, as shadow and most of us have, turn each rocker arm nut counter clockwise (CCW) until the rocker arm starts to clatter. Turn it CW slowly until the clatter just stops. This is zwero lash. Turn (tighten) it an additional 1/4 turn, waiting 10 seconds each time, until each nut has been turned down one full turn. This one, preload adjustment, must be done slowly to allow the lifter to adjust itself and prevfent possible interference between the intake valve head and the top of the piston. Noisy lifters should be replaced."

Shadow: buy, and get to know a manual for your car. Read it carefully with each procedure, step by step. Continue to ask experienced mechanics for help. Some tricks are not in the books.

I have used 1/2 to a full turn preload. Engines vary, but the stockers would do okay with a full turn or a half turn past 'quiet'.

Please learn form my experience in one thing. If you install a new camshaft, install new lifters. Use the lifters specified by the cam provider or your warranty might be invalid. Coast Corvette sold me a nice Comp cam, but included whoooozit lifters. Guess how long it took for one lobe to flatten? No warranty, pal.

Follow the manufactures instructions, as to break in, pre-lube, etc. You don't want to do the job again, or break a valve or piston. It's not rocket science, but knowledge and care is required.

Da Shadow knows, a guy built it; another guy can fix it.

:w
 
Joined
Oct 30, 2001
Messages
2,273
Location
Glen Burnie, MD, USA
Corvette
1986 Bright Red Coupe
Re: 1/2 way done

trackitman said:
I
I eyed the drivers side, it seems to me the bracket for the a/c and alternator is in the way to get the rocker cover off. Anyone know if it comes off easy? The passenger side was a pain because of the exhaust recycle pipe. I could only guess the drivers side is difficult also.

Thanks.

I just did this about a week ago - twice (don't ask). If you remove the belt and loosen the bolts for the topmost bracket (is that AC? Thought it was PS) then you can slide the cover past it. Alt is no prob. My Haynes suggests lifting the car and removing the plug wire mounts at the back of each head; this would certainly make taking off the cover a much easier job, but I couldn't easily get to those mounts...
[RICHR]
 
Joined
Jun 20, 2002
Messages
2,509
Location
Tallahassee, FL
Corvette
none right now :(
LT1's have a problem with the bracket being in the way... gotta take it off... Also keep in mind... for test purposes on an LT1/LT4 you can run the car with no belt because the waterpump is camshaft driven... Also, since you have a 1992, you have no MAF, so you can run without putting the intake parts back (you will have to take it off to get the belt off)+(assuming it isn't dirty air)
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Vetteskins

Advertise with the Corvette Action Center!

Double Your Chances!

Partners

Top Bottom