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Adjusting Valves while engine is running?

 
Shawns66Mustang
New User
Posts: 28
Joined: 01/08
Posted: 09/20/12 12:53 PM

I'm looking for the correct procedure for adjusting valve while the engine is running? I have a new 302 with hydraulic lifters.
I have a set of old valve covers that I’m going to cut slot into. So do I back off until I hear a chatter,  then tighten until it goes away and then a ½ turn??  

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waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 09/20/12 02:47 PM

WAIT...
there are three types of rockers on small block fords...

two of the three stock rocker types are NON adjustable..

the early early motors use a 3/8 stud with 3/8 threads ..

starting somewhere in 69.. ford went to a NON adjustable rocker stud style..

with a 3/8 stud with a shoulder and 5/16 threads...

then they went to pedestal type that uses a BOLT through the rocker arm fulcrum...

let me show you...

these are the second type with a 5/16 thread size on the top of the stud...

Fordstudmountedrocket

this is the proper way to check the rocker arm preload..

Fordhydrauliccamclearancecheck2
with NON adjustable rocker arms..  you normally slowly depress the lifter plunger then check at the tip of the rocker around for i think around 0.090 clearance..  with the lifter bottomed out and the cam in the proper position   so the lifter is not pushed up by the lobe... this gives you the best valve train adjustment


this is the mid 70s  version with rail guided rockers...

Fordrockerarmfulcrumrailstyle

the even later ones have the alignment groove machined in the top of the heads..

Fordrockerarmfulcrumstyle

please describe your rocker arm type or the casting numbers on the heads...

we don't want you having valve issues..

wayne...  

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waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 09/20/12 03:27 PM

there are a bunch of ways NOT LISTED IN ANY BOOK to adjust NON adjustable ford rocker arms depending on which type..

there are slightly longer and slightly shorter push rods available from companies like Elgin engine parts... NOT MELLING..  

there are for pedestal mounted rocker arms.. shims that go under the pedestal. to decrease preload...

and a trick that i have done... grind the foot on the pedestal... to slightly tighten the preload...


one more thing...

i mark the crank... TDC and every quarter turn from there...

i start with the crank at TDC.   the valves for the number 1 cylinder.. NON moving  as i bring the crank to TDC.. i adjust the valves for the number one....  i turn the crank a quarter turn..  and adjust the valves for the next cylinder in the firing order....

then another quarter turn of the crank... and adjust the valves for that cylinder in the firing order...

another quarter turn and the valve for that...

and other quarter turn and you are back at TDC but this is only one turn so you will be starting on the second half of the firing order...

i guess i should get with the magazine staff and give them enough info to write a proper article on the various valve adjustments..   i wonder if they are ever in the el segundo offices.. i might just drop by.. i am not far from there..  

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Shawns66Mustang
New User
Posts: 28
Joined: 01/08
Posted: 09/20/12 06:30 PM

I have the older adjustable valves. I've adjusted them before I started the new motor but was told the best way is to adjust them while the engine is running.  

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waynep71222
Enthusiast
Posts: 455
Joined: 04/12
Posted: 09/21/12 04:03 AM

great...  

cold the rockers can be preset... in a similar system to running...

find ZERO....   go somewhere between 1/4 and 3/4 turn down... but the trick really is...

jotting down the proper firing order..    starting with the crank at TDC... figuring out which cylinder is on the compression stroke...  as you are rotating it... either the #1 cylinder of the fifth in the firing order will have the exhaust valve moving..    remember two turns of the crank to one turn of the cam...    marking the damper every 1/4 turn.. allows you to follow the firing order so the cam is always on the base circle when you adjust the valves... makes it really easy...

1/4 turn each time on a V8
1/3 of a turn on an six
1/2 turn on a four...

i worked in an engine builder.. where i learned this... cold presetting adjustment...

one thing... you have to understand that with a new lifter... you want to NOT bottom the lifter out with the adjustment..  just move the internal piston down away from the snap ring a fraction of an inch...  very similar to what you are doing with the engine running...


you can also watch the valves..  turn the crank 1/2 turn after the intake valve closes.. at that will be TDC for that cylinder..  again you need the crank marked..

a hint..

15426378 is the normal 289/302 firing order.

break it in half
1542
6378

if you paint on your damper...   1/6  then a quarter turn from there 5/3 another quarter turn 4/7 then another quarter turn 2/8  you will know almost which valves to adjust

you still need to know which is on the at TDC at the end of the compression stroke and which is between the exhaust and the intake stroke..  

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jlg2002
Guru
Posts: 1410
Joined: 03/08
Posted: 09/21/12 12:36 PM

Icon QuoteShawns66Mustang:
I'm looking for the correct procedure for adjusting valve while the engine is running? I have a new 302 with hydraulic lifters.
I have a set of old valve covers that I’m going to cut slot into. So do I back off until I hear a chatter,  then tighten until it goes away and then a ½ turn??


Yes your procedure is accurate. or

You can back off the rocker nut until chatter then tighten to zero lash (chatter just goes away). Do this on all the valves.  Then shut down the engine and then take the the 1/2 turn more with the engine shut off. let it stabilize shut down for 5 minutes then restart briefly and all should be quiet.

I've used the last procedure for 35+ years and it cuts down on the mess the oil from the pushrod holes causes.  

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