Thread: Valve Train Noise

Tweet

Ok, so after building hundreds of turbine engines for aircraft, I thought I give a rebuild to 350 sitting in a 57 chevy pu a shot. All went well, however, I have louder than expected valve train noise, especially from #1 exhaust where I put a stethoscope on the head and can very obviously hear a distinct tick at that location and not so much in others. First thought is bad lifter. I have read that a hydraulic roller setup is more noisy than a hydraulic flat with higher profiles on the roller setup. Did do the 1/2 turn after 0 lash and also tried to adjust running, with a notched out old valve cover of course. No joy on changing the audio on that #1 exhaust. Decided to investigate the #1 exhaust area anyway since why one and not others? Found what I thought were some unusual heat marks on one side of the rocker roller. (Photo's attached). Did not see this discoloration on others except for one other on #7 exhaust which is the second loudest under the stethoscope. Valve geometry appears to be on. Has anyone else have this issue with these indications and noise? Engine is strong and runs great, just the valve noise and heat marks that concern me.

Here is the engine setup:
Chevy 355
AFR-0916 heads w\ 1.209 OD springs at 135#, 65cc
Comp 280HR Cam
Comp 853-16 Retro Lifters
Comp 19002-19 Rockers 1.6
Hypereutectic pistons @ -6cc
Compression Ratio= 9.66:1

I have talked to Comp Cams on the issue and they do not have an answer as of yet. In reviewing this froum, I looks like a lot of smart folks out there so thought I will give it a shot.