Rebuilt heads first startup clicking noise???

[Jeremy0201]

So I finally got the heads rebuilt and everything back together now there's a rapid clicking noise that increases with rpms. Almost as if the fan was hittin leather strap .. Lifter rocker noise ?? It's the torque down and go style any thoughts ? I didn't touch the bottom end and no knocking prior.. Thanks I need help..

 

[Jeremy0201]

Oh 302 off a 79

 

[asinor]

Hydraulic cam or solid lifter?
Did you set the lash?
Did you prime your hydraulic lifters?

 

[Jeremy0201]

No prime.. Not sure how. Standard 302 didn't set lash not sure how.

 

[blubuckaroo]

Did you tighten the rockers down in a progressive order with each cylinder at top dead center? If you just tightened them all down you may have bent some push rods or pulled out some rocker studs.

 

[Jeremy0201]

I studied up on everything about head gasket/ manifold install, never heard of this mentioned aside from correctly torquing them down..

 

[csmith441]

I'm in the same boat.... I just got a 75' set of heads with hardened seat placed on my 72 EBs 302. I have the same noise, like the lifters are about to blow out the valve covers.
The mechanic that installed the rebuilt heads told me my cam was flat, even though it was not flat before I got the new heads on. I have driven the EB 10 miles since the rebuild three months ago.

Sorry, Not trying to steal your thread..... ill be watching this.

 

[John Marinan]

Do you have positive stop rocker arms on the heads? The valve train changed on the 78 302. The rocker arms bolt to the heads, there are no studs. The rocker arms are only adjustable by using a different length pushrod. If you used the same pushrods, rocker arms, sled fulcrums, and u channels, you should not need to adjust anything.

 

[bmc69]

Standard 302 didn't set lash not sure how.

Don't worry...you can't..at least not with the rocker nut (or bolt).

If a significant amount of material had to be taken off the heads, and adding to that the typical recession distance a valve job can produce, worsened more if the stems were ground, its not uncommon to need pedestal shims on the fulcrums style. All those are are little square metal spacers that go under the fulcrum for the rocker arm and they come in .010" and .020" thicknesses.

And as a previous poster noted...you might have to get shorter pushrods if you have the earlier type positive stop studs and not fulcrums.

As you torque each down, you should check to see how much preload you have. Carefully note the distance you turn the nut (or bolt, if fulcrum style) after reaching the zero-lash position as determined by spinning the pushrod in your fingers as you slowly tighten the nut. The correct range for the lifter preload is roughly from one-half to one full turn of the nut (or bolt) after zero lash. Much more than one full turn and you are heading towards having too much preload on the lifter and it might not function properly and make a racket.

 

[Amac70]

But you still need to torque them down in sequence with the valves closed the rotate motor and do next set, also checking to make sure the push rods still spin freely. should prime the lifters also. and make sure you free flowing oil from all the pushrods.

 

[bmc69]

But you still need to torque them down in sequence with the valves closed the rotate motor and do next set, also checking to make sure the push rods still spin freely. should prime the lifters also. and make sure you free flowing oil from all the pushrods.

Only if you need to measure the preload distance (certainly a good idea with remanned heads). Otherwise you can just torque and go.

It is NOT advised to "prime" lifters. I realize that myth has been around forever but all that you should do is soak them briefly in motor oil before installing. The lifter is designed to quickly pump itself up to correct length right after starting. Conversely, a lifter installed in the fully extended condition will not let the valve fully close until after it has "relaxed" and expelled some of the excess oil trapped in it.

 

[BUCKNBRONK]

sounds like the hyd lifters wernt primed, they should quiet down after the air is worked out of the system. next time put the lifters in a can of oil and pump them before install.
how long did u run it? u can also pull the dissy and prime the oil system with a drill to get most of the air out and the oil thru all the passageways. were these new or old lifters? if they were old did u make sure they went back in same holes each one came out of?

 

[SDlivin]

or small exhaust leak?

 

[bmc69]

From any number of engine builder's sites and as also stated by cam and lifter manufactures everywhere:

Hydraulic lifters are self adjusting. The adjustment you make beyond Zero Lash is to get the lifter in the center of its self adjusting range. If the lifters are completely filled with oil, they are at the maximum end of their self ajustment range. Without a chance to blead down and adjust themselves, there is a chance the valves could be held open and kiss the pistons.

 

[bmc69]

or small exhaust leak?

Amazing how the tick of an exhaust leak can sound mechanical....

 

[broncodriver99]

I am going through the same thing. I just did the torque and go per the shop manual. I have one lifter that still has a constant tic, but if I don't start it for a couple of weeks it sounds like a diesel for about 5-10 seconds when it first starts up. I think I know the answer but should I pull the valve covers and recheck the lash?

 

[bmc69]

I am going through the same thing. I just did the torque and go per the shop manual. I have one lifter that still has a constant tic, but if I don't start it for a couple of weeks it sounds like a diesel for about 5-10 seconds when it first starts up. I think I know the answer but should I pull the valve covers and recheck the lash?

New lifters?

 

[broncodriver99]

New lifters?

No. Just pulled the heads and relapped the valves after cleaning all of the carbon off of the intake valve stems. Push rods and rockers went back on the same cylinders. I did replace all of the fulcrums as a few were scored pretty bad. I also replaced all of the valve springs. The old ones were the originals and had gotten pretty weak/compressed.