VALVE adjustment help, professionals only !!
04-01-2009, 01:38 PM
#1
3rd Gear Member
Thread Starter
Join Date: Nov 2008
Location: cyprus
Posts: 518
VALVE adjustment help, professionals only !!
Hi guys, thanks for those who helped me with the TQ problem, here i got another small issue.
I have a 69 stang, 302 engine but the 302 is reads D4.... so its a 1974 engine probably off a fairline....anyway heres the problem
I asked a question about valve adjusting and got many answers about twirling the push rods and then at zero lash, go a 1/2 turn to a 3/4 turn on the bolt and then rock the rocker down and do the same for the other....
anyway, after adjusting all the valves, i ran the car for an hour, drove up the block and came back.....then heard some knockin in the valve covers, took them off and had a couple loose...
here are my questions
1, if this is the correct method, should i adjust valves when the engine is warm, hot or cold?
2. could the method i use be just to torque down the rockers? it seems that every time i use the method im doing with zero lash and then giving it a 1/2 turn or so, they loosen up again. and there are some rockers that i cant give it more than 1/4 turn cause its at the end it the threads...
any ideas....
I have a 69 stang, 302 engine but the 302 is reads D4.... so its a 1974 engine probably off a fairline....anyway heres the problem
I asked a question about valve adjusting and got many answers about twirling the push rods and then at zero lash, go a 1/2 turn to a 3/4 turn on the bolt and then rock the rocker down and do the same for the other....
anyway, after adjusting all the valves, i ran the car for an hour, drove up the block and came back.....then heard some knockin in the valve covers, took them off and had a couple loose...
here are my questions
1, if this is the correct method, should i adjust valves when the engine is warm, hot or cold?
2. could the method i use be just to torque down the rockers? it seems that every time i use the method im doing with zero lash and then giving it a 1/2 turn or so, they loosen up again. and there are some rockers that i cant give it more than 1/4 turn cause its at the end it the threads...
any ideas....
04-01-2009, 02:12 PM
#3
4th Gear Member
Join Date: Mar 2007
Location: Chandler, Az
Posts: 1,080
Look at the studs, if they have a shoulder on them you just torque them down. The threaded part of the stud will flare out at the bottom of the threads.
Found a pic
BTW, the correct nuts will have a matching bevel. 18-22 ft/lbs
Found a pic
BTW, the correct nuts will have a matching bevel. 18-22 ft/lbs
Last edited by Gary H; 04-01-2009 at 03:05 PM.
04-01-2009, 02:22 PM
#4
Gentleman's Relish
Join Date: Feb 2005
Location: AZ
Posts: 13,090
1) Do valve lash adjustment when warm
2) The whole 1/4 turn 1/2 turn is tricky. I normally recommend torquing down the valve lash adjust nut vs using the 1/4 1/2 trick. I would only recommend the turning method it if you don't have access to a reliable (read accurate) torque wrench as you may (and your case did) get the backing off from not being tightend down properly.
3) Be sure to recheck the tightness after a couple of heating cycles or use blue Loctite (medium strength) to keep the nuts from backing off.
2) The whole 1/4 turn 1/2 turn is tricky. I normally recommend torquing down the valve lash adjust nut vs using the 1/4 1/2 trick. I would only recommend the turning method it if you don't have access to a reliable (read accurate) torque wrench as you may (and your case did) get the backing off from not being tightend down properly.
3) Be sure to recheck the tightness after a couple of heating cycles or use blue Loctite (medium strength) to keep the nuts from backing off.
04-01-2009, 03:23 PM
#7
4th Gear Member
Join Date: Jun 2006
Location: Fontana, California
Posts: 1,483
The correct procedure for a stud type rocker arm adjustement is to tighten the rocker arm to remove clearance to the pushrod with the cylinder on the compression stroke; from there 3/4 turn more. Part 8-1, section 2 of a FSM has the FORD procedure.
I can tell you from my many years of of turning wrenches that starting the engine with the valve covers off (buy the little oil hole clips) and turning the nuts down until the clacking stops is by far the easiest way to get-er done. Shut the car off, turn 1/2 -3/4 turn more and you're there. Clean up the mess and it's good to go. If they continue to come loose you have worn out rocker nut problems or if not loose you have a bad lifter that's pumping down excessively (or a worn out cam).
04-01-2009, 03:34 PM
#10
3rd Gear Member
Thread Starter
Join Date: Nov 2008
Location: cyprus
Posts: 518
well the few times i tried i would crank the engine (trip via batt and starter), i would start at cyl 1, wait for the exhaust to be at its lowest position and then adjust the intake, feel the pushrod until no play, then tighten 1/2 to 3/4 turn. Then i would wait for intake to be at lowest, and adjust exhaust the same way. Now some wouldnt allow me to go 3/4 turn as i would be at the bottom of the bolt already....
also, when i do the adjustment, then start the engine for a bit, when i examine the rockers, i can feel some play in several of the rockers and feel the pushrod twirl in my fingers which means they are not tight, meaning they loosened due to play and hydr. pressure.
i think i should torque the suckers.... i mean they are almost there anyway..
whats the correct way? what distiguishes you to do the first method or to do the torque method?
also, when i do the adjustment, then start the engine for a bit, when i examine the rockers, i can feel some play in several of the rockers and feel the pushrod twirl in my fingers which means they are not tight, meaning they loosened due to play and hydr. pressure.
i think i should torque the suckers.... i mean they are almost there anyway..
whats the correct way? what distiguishes you to do the first method or to do the torque method?