Hello, I am currently working on my 67 ca gs with my 12 yr old boy. I’m new to working on the internals of engines. I’ve sent the carb in to be rebuilt and removed the intake manifold on my 340-4 to replace the intake gasket that was doin nothing but leaking down the back side. The thing runs pretty good considering it sat for many years. Now that it’s manifold is off I’m looking at the Buick manual along with the rocker assembly, rods, and lifters going why not take them off and clean them up? I’m not sure if by doin this the valves will then need to be adjusted? I’m avoiding taking the heads off if at all possible. My funds are limited but don’t want to seal the intake up without doing something easy that will help the function of this engine. Any help or advise about what to do or not do while the intake manifold is off is greatly appreciated.
Don't take the lifters out and get them mixed up from where they are now. They are matched to the cam lobes. Are the rockers sludged up? Keep pushrods in same holes also. You won't need to adjust anything on reassembly.
Yeah the rockers seem pretty dirty and when it was running I felt like the passenger side was less flow of oil and I thinks the rocker shaft may have gunk in it?
It never hurts to ckean stuff, as Mart said, do not mix the lifters ( you shouldn't need to remove them), be sure they stay with the same cam lobe. These rockers lube through a pressurized hole in the head up through the rocker shafts, it doesn't hurt to clean them. BTW, the valves are non-adjustable.
Take rockers off, tank clean with mineral spirits & a brush. Put them back on same sides so wear is maintained the same as it is. Plug up drain areas on heads with rags or rubber cork to catch spirits from draining into motor. Clean springs, retainers, etc with brush also. Do best you can without complete removal, valvejob, etc.
Thanks for the advice! It looks like the rockers and shaft come out in one piece/assembly and bolt back in fairly easily? Thanks
Loosen each bolt a little at a time going from bolt to bolt until totally loose. Also, be careful when putting it all back together that you also tighten them a little at a time, making sure the push rods stay lined up in the rocker arm cups.
I take rocker shafts to the solvent at work and while holding upside down pull rocker against spring to allow cleaner to enter oiling hole. The grey sludge that accumulates can often be seen. As this is first section to receive pressurized oil if it's suppl is low here , it's low everywhere.. Timing chain replacement I recommend since you're halfway there anyway. Also it wouldn't hurt to pull one lifter for an idea of internal condition. Long life is dependent on upkeep of oiling system.
