logue636@comcast.net
Well-known member
Can someone tell me how to adjust a set of adjustable rocker arms on a S- code 390?
COMMUNITY
1968 GT/CS & HCS
2007+ GT/CS
1966-1967 HCS
-
Welcome to the CaliforniaSpecial.com forums! - You are currently viewing the forums as a GUEST. To take advantage of all our site features, please take a moment to join our community! It's fast, simple and absolutely free.If you have problems registering or can't log into your account, please contact Admin.Please Note: If you are an existing member and your password no longer works, click here to reset it.
1968 How to adjust rocker arms on 390
- Thread starter logue636@comcast.net
- Start date
CougarCJ
Well-known member
- Joined
- Jul 17, 2006
- Messages
- 2,193
Trick question, S code 390's never came with adjustable rockers.
Did you install aftermarket adjustable rockers or the early FE adjustable rockers?
OP
OP
logue636@comcast.net
Well-known member
yes after market rockers
yes they are after market Hart Land Sharp roller rockers with comp cams cup push rods.
yes they are after market Hart Land Sharp roller rockers with comp cams cup push rods.
robert campbell
Well-known member
- Joined
- Apr 10, 2007
- Messages
- 4,321
I assume you have a hydraulic camshaft? Has the engine been started before? First remove all spark plugs.
If the engine has not been started what I do first is adjust the valves by rolling the motor by hand with a socket on the vibration damper bolt. Mark the vibration damper with four equal marks at 90 degrees apart. Bring the timing mark up on tdc on the damper and adjust the number one valve springs down to zero lash. Just enough to gently touch the rocker to the valve stem. Roll the motor clockwise and watch the number one valve springs. As you roll the motor by hand if the exhaust valve is the first to open you were on the number one cylinder in the firing order and were in the correct position to adjust the valves one at a time using the firing order on the intake manifold. If the intake opens first you were 180 out and not in the firing position. Experiment until you have TDC on the pointer and a clock wise movement of the motor opens the exhaust valve first. Once you are happy you can go roll the motor 90 degrees at a time and adjust each valve through the firing order. It is important to get the valves close for the next step.
Next I use a quality oil pump drive shaft primer to run the oil pump with a 1/2 drive reversible drill motor in the reverse position. I use straight 30 weight oil for engine start ups and it is wonderful if you are in a warm garage. The oil is easier to move. You will burn up a 3/8 drive drill motor doing this. I run the oil pump with the drill until all the rockers have oil driping from them as a result of the oil pump being ran. It is helpful to have you trusty assistant “bob” roll the motor by hand while you run the drill. This helps circulate the oil and hlps prime all the lifters.
Now you need to adjust them again. The lifters are now primed. Go through the order one more time and make sure each is just at zero lash. They may change with the lifters being primed. The worst thing you can do is start a motor with over tightened rocker arms. Now being the anal guy I am is I run the drill motor with the someone turning the engine with the starter. If you are on the engine stand this will be later. Just 30 second bursts. Do it a few times and the motor is really getting oiled up!
Now go over the lifters one more time. You are close. For a new engine bring each rocker down to zero one more time. Then turn the nut 1/4 to 1/2 turn more. This will preload the lifter and should be very close to what you want.
You should be ready to go! If it is a solid cam I do the same thing but adjust to the manufacture recommendation using a feeler gauge. They do not move, but the extra spinning of a new motor with the oil pump running does not hurt a thing.
Rob
If the engine has not been started what I do first is adjust the valves by rolling the motor by hand with a socket on the vibration damper bolt. Mark the vibration damper with four equal marks at 90 degrees apart. Bring the timing mark up on tdc on the damper and adjust the number one valve springs down to zero lash. Just enough to gently touch the rocker to the valve stem. Roll the motor clockwise and watch the number one valve springs. As you roll the motor by hand if the exhaust valve is the first to open you were on the number one cylinder in the firing order and were in the correct position to adjust the valves one at a time using the firing order on the intake manifold. If the intake opens first you were 180 out and not in the firing position. Experiment until you have TDC on the pointer and a clock wise movement of the motor opens the exhaust valve first. Once you are happy you can go roll the motor 90 degrees at a time and adjust each valve through the firing order. It is important to get the valves close for the next step.
Next I use a quality oil pump drive shaft primer to run the oil pump with a 1/2 drive reversible drill motor in the reverse position. I use straight 30 weight oil for engine start ups and it is wonderful if you are in a warm garage. The oil is easier to move. You will burn up a 3/8 drive drill motor doing this. I run the oil pump with the drill until all the rockers have oil driping from them as a result of the oil pump being ran. It is helpful to have you trusty assistant “bob” roll the motor by hand while you run the drill. This helps circulate the oil and hlps prime all the lifters.
Now you need to adjust them again. The lifters are now primed. Go through the order one more time and make sure each is just at zero lash. They may change with the lifters being primed. The worst thing you can do is start a motor with over tightened rocker arms. Now being the anal guy I am is I run the drill motor with the someone turning the engine with the starter. If you are on the engine stand this will be later. Just 30 second bursts. Do it a few times and the motor is really getting oiled up!
Now go over the lifters one more time. You are close. For a new engine bring each rocker down to zero one more time. Then turn the nut 1/4 to 1/2 turn more. This will preload the lifter and should be very close to what you want.
You should be ready to go! If it is a solid cam I do the same thing but adjust to the manufacture recommendation using a feeler gauge. They do not move, but the extra spinning of a new motor with the oil pump running does not hurt a thing.
Rob
