how to adjust valves on 68' 289cuin

I can't seem to find any good threads on how to properly adjust the valves on my 1968 Fairlane 500. It has a 289 with auto. Are they done with a gap for the lash or are they seated halfway down the hyd lifter (two turns)? Thanks

Is the valetrain completely stock? Are you installing new stuff or just maintaining the motor? Hydraulic lifters require some preload. That year motor would have a hyraulic cam. Lash and regular valve adjustments are solid lifter territory. A Hydraulic cam should require no valve adjustment. If it is tiking you may have a collapsed lifer or bent pushrod.

Here is a foolproof way to check they are correct. Start with cyl 1. Rotate the motor when the exhaust valve starts to close you can adjust the intake valve. Loosen the nut holding the rocker arm. Tighten it slowly until there is no lash. Spin the pushrod with your fingers as you tighten the nut. When you can't spin it with the tips of your fingers then you are there. Now tighten the nut one full turn from the zero lash point to give you around .065 of preload. Move to the next cyl that would be 5, (1-5-4-2-6-3-7-8 should be your firing order) in the firing order and when the exhaust is closing there adjust the exhaust on cyl 1 and proceed to adjust the intake of cyl 5. repeat repeat repeat.

As I mentioned before there shouldn't be a need to adjust the valves if the lifters are still in good shape.

Late model 289's have rail rockers and the rocker is cranked all the way down. You have to replace the push rods with over sized or under sizes push rods to get the correct valve lash. Someone will correct me if I'm wrong.

I just installed a top end kit from Edelbrock on my 289 and when I turn the motor over, it seems there is no compression. I adjusted the valves per instructions with all the way snug plus a quarter turn. Why is this doing this? I am befuddled. BTW, it is an early model 64.5 block and came with hydraulic lifters. I used stock length hi performance pushrods.

Originally Posted by 1bad6t

Late model 289's have rail rockers and the rocker is cranked all the way down. You have to replace the push rods with over sized or under sizes push rods to get the correct valve lash. Someone will correct me if I'm wrong.

Their is no such thing as LASH with a Hydraulic cam, its PRELOAD.

Way back when they used to have oil deflector clips that snapped on to the pushrod end to each rocker arm. They were sued to stop giving the final engine tuner a bath of hot oil, by near plugging off the oil coming up the pushrod and allowing it to drip to the channel in each head. If folded correctly they all fit into a simple 35mm film can and can be stored in the glove compartment then.

They ahd a set of instructions too. You turn over the raw engine, the shake adjust the rocker while engine is sitting still. Elininate all the valve lash, then turn adjuater on half more. Add clip-on and go to next. Then start up teh engine, and adjust as per manual, but in easy slow incrementals. Once one side is done, turn of engine, remove clips, install valve cover and go to other side and repeat.

Spilling oil gets smokey on the exhaust manifolds if the clips are not used.

Wm.

I have a set of old valve covers with the top cut out just for such an occasion. Call me stupid if you want, but I do not claim to be a mechanic. Here's my probably dumb question... When adjusting valves with the motor running, what do you listen for, look for, to tell when ya got 'em right? Thanks.

Honestly, their is no need to adjust lifters while the motor is running...... All you do is make a mess !!!

Originally Posted by dfree383

Honestly, their is no need to adjust lifters while the motor is running...... All you do is make a mess !!!

Good advice, still, how do you know when valves are adjusted properly, is it just before they start staying open all the time to get maximum valve travel?