Team Camaro Tech banner

1 - 11 of 11 Posts

·
Premium Member
Joined
·
54 Posts
Discussion Starter #1
Hey I final got my motor built. However I did the zero lash for the pushrods, but I still seem to have some tapping..I did the old spin the pushrode till you can barely turn it but is there a better/precise method of doing it?
 

·
Premium Member
Joined
·
54 Posts
Discussion Starter #3
hydraulic, yes i did pre-soak them in oil..but that just fyi..if you have experience in this issue PLEASE let em know..my engine sounds mean but i have some tap that if any engine builder knows is like echoed 1000 times to the builders ear..people say man that sounds killer but I keep thinking man there is tapping in there lol
 

·
Premium Member
Joined
·
54 Posts
Discussion Starter #5
Great info, but it basically is what I did. Spin the push rod until it can barely spin then tighten the outer bolt a 1/2 turn then tighten internal locking down. maybe I didnt get the proper open of exhaust and intake rocker. Is there anything that I am missing? im rotating the engine to each point. Yet im still hearing that tapping sound..Its strange cause I only here it at the first part of the start then it kinda dies out after it is warm.
 

·
Registered
Joined
·
13,337 Posts
So u are real sure the tapping is the valve train?
Covers on, us a machanics stethoscope..they are real cheap..even thru the covers u will locate damn close which of a pair....
A old tappett cover with top chopped out and covers the tops of the push rods to stop oil hitting the gauds is a must fot any chevy workshop.
With these on using the stethoscope (or long screwdriver held to the ear will ID exactlt which one....
IF u cant hear it..check the inside of the covers...a rocker may just be touching the cover...do not assume it will be touching enough to mark the inside thu....a thicker cork tappet cover gasket usually fixes.

Using the cut out tappet covers on hydrolic lifters, idle the engiine , back off each adjusting nut till it 'clacks' then wind down slowly( or else the engine stalls) till stops clacking....THEN another 1/3 to 3/4 turn.....Chev say 3/4 others say 1/3 others otherstuff.....its a matter ofr personal preverence ...I use 1/2 for what its wiorth.

IF the knock still doesnt go way....new engine right?
Suspect a collapsed piston....hard to loacate...again use the mechanics stethoscope both from the top around covers heads block
AND from underneath....this fault is often haed to find iff it is a center piston, but is usually more noticable from under the car on a hoist.

The cause is usually a lean mixture combined with timing overadvanced on the 1st few seconds of fire up.
 

·
Premium Member
Joined
·
54 Posts
Discussion Starter #7
Great information..I will try those methods and see what happens.
 

·
Registered
Joined
·
91 Posts
Do as advised to try and isolate the noise location. Are you running roller rocker arms? The tend to make a small amount of noise and this is normal.
 

·
Premium Member
Joined
·
54 Posts
Discussion Starter #9
Yea I have roller rockers. Once I get the chance I am going to try it out.
 

·
Super Moderator
Joined
·
32,531 Posts
Could be a stuck lifter, meaning the inner body is stuck in the bottom of the outer body.
To locate, if using a stethoscope, or a long screwdriver with your thumb over the handle and pressed against your ear canal, you can do another method.

Bring engine up to operating temp and shut down.
Remove valve covers.
Turn engine over by hand and:
When exhaust valve starts to open, check intake valve for looseness.
Continue to turn engine.
When intake is almost closed, same cylinder, check exhaust valve for looseness.
You can start at the firing order and follow it through.

If you find a loose rocker, adjust out slack plus a 1/2 turn, and wait for some time, maybe 5-10 minutes.
You should be able to turn pushrod by your fingers as spring pressure will bleed down lifter.
If not, this is your stuck lifter.
 

·
Registered
Joined
·
1,202 Posts
everet is right on this one --cant go wrong that way especially if you have abig cam--and i dont use the push rod turn method--i back off and take the tip of rocker arm and rock it from right to left back forth while tightening -you feel when it hits 0 lash then half turn further
 
1 - 11 of 11 Posts
Top