1963 390 Caddy Rocker Arms

[Jim Hughes cLc #17388]

Hello All,
A firend recently rebuilt a 1963 390 engine. New valves, pistons, bearings, timing chain and gears etc. The heads were milled lightly to clean them up, the block was decked, again lightly, and the rocker arms on the valve ends were cleaned up. A new cam and lifters were purchased from a well know parts supplier in New Jersey and installed too. Any possible problems with the quality of the parts? (they were made in China)
When it was started, it sounded as if the rocker arms were out of adjustment. As these are nonadjustable rockers, any thoughts as to why they are noisy?
The rocker arm assemble were taken apart for clean up. It appears that the rocker supports can be assembled on the shaft in no particular orientation, (rotated 180 degrees on the shaft). Am I wrong in assuming that?  The Motors Manuel makes note on the 1959-1962 390 to make sure that the support is positioned in a certain way. The supports on the 1963 390 appear to be of a different design.  They don't seem to be on upside down either. Wits end here, any suggestions? Many thanks in advance.

[62droptop]

what is the oil pressure? if low is it posible an oil galley plug was left out?

not sure on the 63 390, but the 62 390 has one
was it run properly when first strted to break in the cam with proper break in lube?
if the cam is not run in properly the lobes will be worn off in no time,
usually run at 2000rpm or better for at least 20 minutes on first start up. should not idle until cam is broken in.

also was the cam a regrind and were the rocker arm tips reground?
if so it is possible the base circle of the cam is smaller  now  and with the rocker arms reground , in theory needs longer pushrods(not really likely,but have ran into this before on english stuff )
the lifters may now  be out of their range of compensation

first thing i would check is oil pressure with a reliable gauge


if you have any more more information ,that would be a great help to help solve this issue

[Jim Hughes cLc #17388]

Thanks for the suggestions Lee. Unfortunately, I wasn't there when it was first started so I can't tell you if it was run at higher RPMS. We will put a mechanical pressure gauge on it and go from there.
The cam and lifters are new (from China). Tips of the rockers were reground a few thousands. Probably won't get back on it until later this coming week. I'll post any progress.

[dadscad]

Jim,

According to the 63 shop manual, there is a special orientation of the rocker stands. Under a "Caution" notation on the Assembly instructions, "the thinner end of rocker shaft brackets should be against heads of screws". Oil grooves in rocker shaft should face downward toward the cylinder head and notches in ends of shaft should face engine when assembly is installed on cylinder head. Refacing the rocker arms could have caused more clearance than the lifter can adjust to, you may need longer push rods as 62droptop noted.

Another caution about orientation of rocker shaft brackets, "Make sure thinner end of rocker shaft brackets are right side up or the rocker shaft may be sprung out of alignment when the cap screws are tightened down".

HTH,
David

[Jim Hughes cLc #17388]

Thanks for the information David. We have checked what you mentioned and found that the rockers were assembled correctly. My friend ran the engine at a fast idle on and off for some time and most of the lifters quieted down. There are still two or three that are noisy. Could be that they are defective. We will try to determine which ones they are and pull them out. The saga continues.

Thanks to all you your input.

Jim