valve tap

[oldcarlover]

After adjusting valves as per (valve tip info.section) I still get slight tapping. Should I go a little tighter on adjustment?

[55 Fargo]

I would err on the side of a slight tap, rather than a burnt valve.

I am sure someone with more "in the know" of Me will chime in.....

[greg g]

are you sure it a valve?

[Jim Saraceno]

The heads to the tappets can wear and form a cup on top. If that happens, the adjustment will be off because the gauge will be riding on the top of the ridge where the valve will be riding on the bottom.

When I first got my car, I had several tappets that were cupped close to .012" which doubled my gap.

I'm not sure what you can do to fix it other than identify it and adjust the valves tighter or pull the head, valves and tappet heads and either grind down the heads or replace them.

I had an old guy tell me that he never used a feeler gauge because of that problem. He would tighten the gap until.... well it's been so long I don't remeber what the engine was doing:o, but the engine sounded different then he would back it off "a scosh". I'd never do that but he swore by it.

The main thing is a loose valve makes a click, a tight valve burns up so given a choice, loose is far better than tight.

If you adjust the valves while the engine is running and hot like your supposed to, when you insert the feeler gauge into a loose valve, the clicking will go away so you can quickly identify which valve is the offender.

[Joe Flanagan]

And though it's a pain in the neck to do, it's a sure way to find the guilty tappet, as Jim says. As soon as you slip the feeler gauge into the one that's making noise, it will sound like a different engine.

[TodFitch]

  Jim Saraceno said:

...snip...I had an old guy tell me that he never used a feeler gauge because of that problem. He would tighten the gap until.... well it's been so long I don't remeber what the engine was doing:o, but the engine sounded different then he would back it off "a scosh". I'd never do that but he swore by it. ...snip....

Years ago I had a 63 D200 with a 318 V8 fitted with solid lifters. On that engine the valve lash adjusters were just threaded weird so they were tight in the rocker arms. No other locks to hold them in place. First long trip after I did a valve job, at night crossing the desert to Tucson, the engine started making a hellacious racket. Pulled into a rest stop and slept until morning then I isolated the noise to the driver side valve area. Pulled the valve cover and isolated it to a very loose valve. I did not have feeler gauges with me, so I just adjusted it until the noise went away. Put the cover back on and drove the remaining 200 miles.

Once at the folk's house, I pulled the cover and measured the lash: It was within spec. So either I got really lucky, or the spec on that engine was just where the tappet noise goes away. I did pull the adjuster screw out and modified the threads (with a hammer) so that it would not work loose again, put everything back together and never had a problem there again.

Anyway, my take away from that experience was that you can get close to the correct adjustment by using your ears.

[Andydodge]

Tod, that would have been a 318 poly, they all had solid lifters with those adjusters that have no lock nut, the thread on the adjuster screw & that thru the rocker are some sort of interference fit but if they have been "interfered " with too often they come loose..........lol......ask me How I know...........lol......btw the hammer repair method is the recomended repair...........andyd