BoatBanter.com - View Single Post

In article ,
says...

Gundmundur,

Thanks for the tips. I advanced the timing a couple of inch's this time
(instead of just a few º). I played around with until until I got the best
performance. It seems to be running really good right now. But I still
have that ting ting ting. If I adjust the rocker arms witht he engine
running, is oil going to go everywhere?

I have an old valve cover that I used a Greenlee 3/4 inch punch to
place 8 holes exactly centered over the rocker studs. This allows my
5/8 inch deep well socket to fit down over the adjustment nut.

When you adjust the rocker, back off very slowly until you hear the
tick-tick-tick. Then very slowly turn the adjustment clockwise until
the ticking stops. Proceed to adjust 1/4 to 1/2 turn tighter, but not
more than 1/2!

You will develope a feel for this adjustment. Your lifters are oil
filled hydraulic, and the whole point is that they 'compensate' for
normal wear in the valve train. While you are adjusting they are
dynamically changing. If you adjust to loose, they will reach the end
of their travel, and you will hear the ticking. If you adjust to tight,
the engine will idle rough as hell, not take a load at low rpm, and
probably burn the valves from not seating completely at high rpm.

A slight tick-tick-tick at very low idle rpm is tolerable and even
somewhat normal, so long as the ticking stops almost as soon as the
engine is brought above idle.

Two things to remember on Chevy rocker adjustment. 1 the studs are
pressed in and known to back out. If after proper adjustment, you
run the engine for several hours at high rpm and the ticking comes
back and sounds more like loud clacking, look for a stud which is
no longer anchored firmly in the head. 2 the adjustment is supposed
to be self locking, but if you play with the adjustment to much it
loses the ability to self lock and will begin to drift to the loose
side followed by the return of clicking noises. This is why all
serious high endurance engines change over to screw in studs and
jamnut adjusters. Some even run 'rocker stud girdles'.

Best wishes. Writing this reminds me that I need to go spend some
time under the hood of my tow vehicle. 1948 streetrod pickup truck.
Haven't messed with anything under the hood in 5 years other than
oil changes. Think it's about time for plug wires and a tune up.

Gummi (Icelandic horseman now boating in America)