Adjusting my valves

[gray85]

Adjusting my values

I have just recently had my engine overhauled (85 vette) and replaced the heads (edlebrook aluminum heads, hydraulic lifters). I can't seem to find any (accurate) information on how much to tighten the rocker arm bolts. Please provide information or refer me to book that could help me.

Thanks in advance
Tom

 

[78SilvAnniv]

Hi Tom,
Hopefully someone else will be along to verify accurate information for your application.

I looked up in my Workbench Book, How to Build the Smallblock Chevrolet the torque specs for rocker arm bolts.
The book I have says 50 foot/pounds for rockerarm studs. I do not know if your heads being aluminum make a difference. To truly ease your worries, I would call a local and respected speed shop and ask them, or perhaps call the supplier of your heads.
Heidi

 

[gray85]

HeidiThank you very very much for your advice. You always give it your best shot!


Tuna


Please forgive me I should have been more clear. I have two books that I am using Haynes manual (84-91) and how to rebuild your SMALL-BLOCK CHEVY 1979. I am trying to adjust my values and the two books contradict each other. After removing the excessive clearance in the pushrod (by tightening the adjusting nut on the rocker arm), it instructs me tighten the adjusting nut further (SMALL-BLOCK 1/2 turn and Haynes 1 turn) (cylinder at TDC). Does anyone have advice on this or a book that might be helpful?

Maybe I need to give some backround information. I have completed the engine overhaul and the car is running, but the values don't seem to be set right. I have adjusted them several times (3 hour operation), I am about to give up and bring it to a shop, but want to try one more time.

 

[cablexpert]

Adjusting valves

Try this site gray.......www.compcams.com

 

[drags1998]

I have always ajusted valves with the engine NOT RUNNING. Follow the manual & set the valves some where around 1/2-3/4 of a turn after removing all play from each valve.This SPEC. is always a matter of opinion! now you have mine!

 

[jmccloud]

(SMALL-BLOCK 1/2 turn and Haynes 1 turn)

1/2 to 1 turn is about right. If the engine is good and hot when adjusted, you can go 'tight' but if it's cold, go 'loose' or 1/2 turn. Most lifters have about 3 'turns' worth of adjust but if you go too tight, a valve could remain open and burn. I prefer to go 1/2 or 3/4 on a hydraulic cam. If the valves don't 'tick' when cold, they're OK.
If the lifters are 'mechanical', adjust when hot and running (really messy) and exactly to the cam/engine mfgr's. spec.

 

[cablexpert]

That works for me too drags...sounds like he might have another problem

 

[rrubel]

Remember that each cylinder hits TDC TWICE - once on the intake cycle and once on the exhaust cycle. Make sure you're adjusting the right rocker at the right time. I made that mistake and it seemed like they were getting loose when they had just been tightened...
[RICHR]

 

[bossvette]

I like to adjust mine hot and running, I have a old valve cover with the center cut out so I can get at the locks. I back it off till it "clicks" and then slowly tighten till it stops clicking then tighten 1/2 a turn. There is a procedure for setting the valves cold I believe it is to set the exhaust when the intake starts to close and the intake when the exhaust starts to open when turning the crank by hand in the correct rotation. Most cam grinders have this procedure in their catalogs.
Craig sr.

 

[cntrhub]

Here is a real simple way of adjusting valves. It is also one of the most accurate adjustments. It's an old NASCAR engine assembly trick. Begin with any cylinder you want. Rember to stop turning the crank...."As-Soon-As"....you see one of the pushrods begin to move. This is key to remember.

OK, here we go: EO = Exhaust Opens. IC = Intake Closes.
Lets say, you start moving the crank (pick a cylinder).... now keep turning the crank and watch for the intake's rod (for example) start to close. As soon as you see the slighest movement of the, "Intake Close" (IC)...STOP!
Now set the exhaust pushrod to specs. Say the adjustment calls for one full turn (stock adjustment) from zero play. Without making too drastic of a move to unseat the rod from the lifter, start moving the pushrod up and down. Keep doing this until there is just the slightest up and down movement. Then, begin spinning the pushrod as you keep tighten the rocker nut. When you can no longer spin (a subtle touch as you tighten very slowly) the rod, stop.
Place the wrench at a known starting point, and turn the rocker nut 360 degrees... and stop. One full turn is a standard adjustment for a stock engine. Consult with the "performance specs" of their adjustments. It might be less or more turns....depending, etc. Solid lifters on the other hand, will take a different adjustment approach.

Now turn the crank, and watch for the exhaust just begin to open (EO). As soon as you see this happen, STOP! Set the intake valve to specs in the same manor stated above. You've completed an adjustment of one cylinder. There are 7 more to go. This is a lot quicker and more accurate (bottom of heel) than finding TDC of each cylinder. Hope this helps.

 

[Ken]

Thanks Hollywood!

Tom, I'm going to move this to the "Mods" forum since you have modified the engine.

 

[grumpyvette]

heres several methods

http://www.2quicknovas.com/happyvalves.html
http://www.jimcookperformance.com/TechNotes/TN7ValvLash.html

http://www.centuryperformance.com/valveadjustment.asp

http://www.babcox.com/editorial/us/uhs89720.htm

http://www.boostandfuel.com/support/setting_valves.htm

http://www.carcraft.com/techarticles/87998/index2.html

http://www.angelfire.com/fl4/pontiacdude428/valveadj.html

btw if your totally new at this the tappet feeler gauge measures the lash clearance between the valve and rocker on solid lifter cams

I just don,t think adjusting the valves without the oil pressure and the block up to operating temp. is the best way to adjust valves , but yes you can do it just fine with several methods discribed above

how do you adjust valves at idle without the mess of oil getting all over the engine and headers

HIT A FEW YARD SALES, SWAP MEETS UNTILL YOU FIND A DIRT CHEAP SET OF TALL CAST VALVE COVERS LIKE THESE, the CONDITION THEY ARE IN ,WITHIN REASONABLE LIMITS OF COURSE IS NOT THAT IMPORTANT

you simply cut the ribbed center section out of the valve cover, and glue the synthetic valve cover gaskets on them in the normal location,
when you go to adjust the valves you first remove the standard valve covers and install your VALVE ADJUSTMENT COVERS, they retain about 80%-90% of the oil that would normally be lost over the edge of the cylinder head while adjusting a running engine, they also catch much of the splashed oil, just leave a 1/4"-3/8" of the rolled top for strenth around the perimiter of the top surface. I bought my set for $10, they were old and slightly discolored but I could not care less! I took them home and used a drill and saber saw to remove the center ribbed area, theres several brands that are very similar in appearance, all will work! and Ive used them for over 25 years, if I remember correctly they are mickey thompson brand

now if the lifters are hydrolic of course you just back the adjustment nuts off the rocker studs with a wrench, slowly until the rocker JUST starts clicking , then slowly tighten the nut just up to the point that the clicking stops then add 1/4 to 3/8 turn to preload the lifter and move to the next rocker and repeat, the only differance with solid lifters is you use a feeler gauge inserted between the valve tip and rocker after they click slightly,to measure the lash distance recomended on the cam spec. card (normally .016-.028 thousands) and you tighten them just to the point at idle that the clicking stops... then you remove the feeler gauge and move to the next rocker
if your useing jam nuts dont forget to lock the allen key

 

[Ken]

HIT A FEW YARD SALES, SWAP MEETS UNTILL YOU FIND A DIRT CHEAP SET OF TALL CAST VALVE COVERS ...

Good tip, Grump.

_ken

 

[Moonunit 451]

1/2 to 3/4 turns with hydrolic lifters seems to be common wisdom.