Silent Lifter? Why?
Thread Starter
Intermediate
Joined: May 2006
Posts: 38
Likes: 0
From: California
Silent Lifter? Why?
1979 Vette, 383 Cui Stroker
I have never run into this occurence before so I need a bit of insight.
I was adjusting my lifters with the engine running, backing off until it rattled, then turned until it was silent, then added 1/4 turn. For 15 of the 16 valves this worked as usual, on the 16th valve (exhaust valve cylinder #8), as I loosened the nut on the rocker, there was no "rattle", so I kept backing the nut off, and backing it off even more, 1/8" then to 3/16" or more, still no rattle. The rocker is moving up and down as normal, the spring looks fine, the push rod is there! I am a bit baffled as to why I am not getting the "tappng" of a loose push rod and lifter? Any insight guys? The engine sounds and seems normal, but this does not seem right. The manifold vacuum reading is steady at 20 Hg. Timing is at 8 BTDC.
The studs are threaded into the head, and I have push rod guides.
I have never run into this occurence before so I need a bit of insight.
I was adjusting my lifters with the engine running, backing off until it rattled, then turned until it was silent, then added 1/4 turn. For 15 of the 16 valves this worked as usual, on the 16th valve (exhaust valve cylinder #8), as I loosened the nut on the rocker, there was no "rattle", so I kept backing the nut off, and backing it off even more, 1/8" then to 3/16" or more, still no rattle. The rocker is moving up and down as normal, the spring looks fine, the push rod is there! I am a bit baffled as to why I am not getting the "tappng" of a loose push rod and lifter? Any insight guys? The engine sounds and seems normal, but this does not seem right. The manifold vacuum reading is steady at 20 Hg. Timing is at 8 BTDC.
The studs are threaded into the head, and I have push rod guides.
Racer
Joined: Feb 2007
Posts: 262
Likes: 2
From: FREDERICKSBURG VA
With the engine off, rotate the engine til #8 exh is on the heel of the cam. Loosen the rocker nut until the pushrod is loose, tighten until the pushrod is tight, go another 1/4 turn. Start the engine & try it again.
Thread Starter
Intermediate
Joined: May 2006
Posts: 38
Likes: 0
From: California
Thanks everyone for taking a look, and I appreciate the response. I went to attempt to do as you suggested, but first I removed the pushrod because I had noticed that the oil flow through it seemed a bit slow. I inspected the push rod, the through hole was clogged. Easy fixe, cannot understand how it got clogged, as it was cleaned before install. While I had the push rod out I got a very bright light to pear down to see if I could see the lifter, the view I saw seeemd strange, I did not see the tell tale "clip" that is usually very visable when viewing a lifter. It became apparent that the lifter had broken and all the insides, retainer, ball seat, and restrictor plate had all been dislodged. Makes sense now why the lifter was "silent". This is a first for me, I never broke a lifter before. Once again thanks to everyone for looking and the good advice.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Buy some name brand lifters, I know there are only a few companies making flat tappet lifters anymore but you never know, the chinese like to copy anything 
