rawbutt

just had my valved adjusted on fresh 383 with roller rockers and hydraulic roller lifters. i'm getting some fairly loud tapping until it warms up good. does this mean that maybe the mechanic just adjusted them kind of loose. will this hurt anything? should i have them readjusted to try to stop the tapping?

thanks!

ChevyTuffD.A.

What kinf of lifters are u running? If u got the Comp R's they are kind of a pain to adjust and they are very picky. I am willing to bet that is your problem. Were they adjusted with the motor off or have then been adjusted with it running?

rawbutt

Chevy,

I have an itemized sheet where my engine guy wrote down all the parts he used, but it's a little hard to read his writing in some cases. It looks like it says "Engine Tech Hyd LT-1 Roller Lifters".

If the lifters are what I'm hearing, is it hurting anything the way they are? I was under the impression that I had the rockers adjusted recently, but not the lifters. Also, they were adjusted with the motor in.

Ram Air 9C1

You have forged pistons in the sig. It might be piston slap if it goes away when the car is warmed up.

rawbutt

so if it goes away (or at least gets much less noticable) when the car is warmed up, can i assume it's not something causing damage that i need to get figured out immediately?

Jazsun

I wouldnt want piston slap on a newly rebuilt engine. the piston is hitting the side of the cylinder wall.

rawbutt

the reason i tend not to believe it's piston slap is that i noticed it after my mechanic adjusted the rockers recently. i dont really remember it ever making that noise until i got it back from him doing that. could it just be a matter of him adjusting the rockers a little loose vs. doing them a little tighter? is it true that if you run them a little tighter, you loose maybe 50 rpm on the top side, but don't hear the tapping?

ChevyTuffD.A.

I am not sure about your knowledge on doing things yourself. The most simple solution for yourself would be to simply pull the valve covers off, which is very easy and see if u can tell where its coming from. Start with the front rocker and lossen it up till u hear it make some noise then tighten back down just to were it stop makin the noise. If he adjusted your rockers with the motor not running then some of the lifters might have not been completely pumped up with oil and he might not have gotten them as accurate is they could be. Talk with your mech and find out if he actually adjusted them with the motor RUNNING.