need info on setting valve lash. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

joelboxt · 04-26-2005, 10:14 PM

Need info on adjusting the valve lash. how many turns? if you could give me the steps. if you have the directions on how to do this running and none running would be good.

thanks.

its a 350SBC pretty much bone stock.

joel

Dean23 · 04-26-2005, 10:18 PM

heres the way i set up the lifters in my small block

1. Remove the valve covers, and pick a cylinder you are going to set the preload on.

2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder’s intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe, the correct position for adjusting the intake.)

3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.)

4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at “Zero Lash”. Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly.

5. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close. When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm.

6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again.

I only go about 3/4 of a turn 1 full turn seems too much

joelboxt · 04-26-2005, 10:30 PM

thanks for the info.. need to set the valves this weekend.. just didnt know the corrent amount to turn them once at zero lash.

how will i turn the engine over by hand tho. its in the truck.

joel

Dean23 · 04-26-2005, 10:34 PM

grab a 5/8 socket and a 1/2 ratchet put it ont the balancer bolt and turn it over. If you leave the plugs out it will turn easily

joelboxt · 04-26-2005, 10:35 PM

was thinking about that. getting out the stong arm or something on the crank bolt.

thanks again for your help

joel

jhow66 · 04-26-2005, 10:35 PM

Quote:

Originally Posted by joelboxt

thanks for the info.. need to set the valves this weekend.. just didnt know the corrent amount to turn them once at zero lash.

how will i turn the engine over by hand tho. its in the truck.

joel

Remove all plugs (makes it easier to turn). Use a breaker bar with a 5/8 socket on bolt on harmonic balancer (remove fan belt so as not to get in your way).

jhow66 · 04-26-2005, 10:37 PM

Shucks-need to type faster. lol

joelboxt · 04-26-2005, 10:57 PM

haha, thanks to the both of you. jhow66 and dean23.

Joel

04-26-2005, 10:14 PM	#1
joelboxt 71 Cheyenne SWB Fleetside Join Date: Jan 2005 Location: Sarnia, Ontario, Canada Posts: 403	need info on setting valve lash. Need info on adjusting the valve lash. how many turns? if you could give me the steps. if you have the directions on how to do this running and none running would be good. thanks. its a 350SBC pretty much bone stock. joel __________________

04-26-2005, 10:18 PM	#2
Dean23 68cst_ss490 Join Date: May 2001 Location: edmonton,canada Posts: 1,363	heres the way i set up the lifters in my small block 1. Remove the valve covers, and pick a cylinder you are going to set the preload on. 2. Hand rotate the engine in its normal direction of rotation and watch the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder’s intake rocker arm. (Why? Because when the exhaust valve is just beginning to open, the intake lifter will be on the base circle of the lobe, the correct position for adjusting the intake.) 3. Back off the intake rocker arm adjuster and remove any tension from the pushrod. Wait a minute or two for that hydraulic lifter to return to a neutral position. The spring inside the lifter will move the pushrod seat up against the retaining lock if you give it time to do so. (If you are installing brand new lifters they will be in the neutral position when they come in the box.) 4. Now spin the intake pushrod with your fingers while tightening down the rocker arm. When you feel a slight resistance to the turning of the pushrod, you are at “Zero Lash”. Turn the adjusting nut down one half to one full turn from that point. Lock the adjuster into position. The intake is now adjusted properly. 5. Continue to hand turn the engine, watching that same intake. It will go to full open and then begin to close. When it is almost closed, stop and adjust the exhaust rocker arm on that particular cylinder. (Again, when we see the intake almost closed, we are sure that exhaust lifter is on the base circle of the lobe.) Loosen the exhaust rocker arm and follow the same procedure described before in steps 3 and 4 to adjust this rocker arm. 6. Both valves on this cylinder are now adjusted, and you can move on to your next cylinder and follow the same procedure again. I only go about 3/4 of a turn 1 full turn seems too much __________________ Dean edmonton,canada a winter wonderland 2005 Chevrolet Avalanche LT cold air intake, performance exhaust, Comp cams cam, jba shorty ceramic headers. http://www.cardomain.com/ride/3090973

04-26-2005, 10:30 PM	#3
joelboxt 71 Cheyenne SWB Fleetside Join Date: Jan 2005 Location: Sarnia, Ontario, Canada Posts: 403	thanks for the info.. need to set the valves this weekend.. just didnt know the corrent amount to turn them once at zero lash. how will i turn the engine over by hand tho. its in the truck. joel __________________

04-26-2005, 10:34 PM	#4
Dean23 68cst_ss490 Join Date: May 2001 Location: edmonton,canada Posts: 1,363	grab a 5/8 socket and a 1/2 ratchet put it ont the balancer bolt and turn it over. If you leave the plugs out it will turn easily __________________ Dean edmonton,canada a winter wonderland 2005 Chevrolet Avalanche LT cold air intake, performance exhaust, Comp cams cam, jba shorty ceramic headers. http://www.cardomain.com/ride/3090973

04-26-2005, 10:35 PM	#5
joelboxt 71 Cheyenne SWB Fleetside Join Date: Jan 2005 Location: Sarnia, Ontario, Canada Posts: 403	was thinking about that. getting out the stong arm or something on the crank bolt. thanks again for your help joel __________________

04-26-2005, 10:37 PM	#7
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Shucks-need to type faster. lol __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

04-26-2005, 10:57 PM	#8
joelboxt 71 Cheyenne SWB Fleetside Join Date: Jan 2005 Location: Sarnia, Ontario, Canada Posts: 403	haha, thanks to the both of you. jhow66 and dean23. Joel __________________



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