Rocker Clatter

[IBM-Tech]

Have recently had a mechanic rebuild what appears to be a stong 355 TPI motor that can handle a vortech supercharger and Nitrous. When he finally gave the car back to me after 2 years 2 months the valves weren't adjusted and the car only ran for around 3 seconds then died.. You could attempt to start it all day long and it would continue to do the same thing. Had a real camaro GURU that helped me adjust the valves and I noticed alot of clatter on the rockers. I got rid of the stock rockers and put new hydraulic Roller rockers in. Almost immediately some of the noise disappeared. I don't think he put new lifters. You can't really notice the noise when the engine is idling. But when you are driving or putting the car under a load,, That is a different story, You can really hear them clatter. This is how I did the valve adjustment on the Roller Rockers.

With the engine running. I loosed the rocker until it started to clatter. Then tightened until it stopped makeing noise, then gave it 1/4 turn to tighten until they were all done.

The engine only has 100 miles since rebuild. I was told to re-adjust the valves at 500 miles and it should be good to go. Any help would be greatly appreciated.

[paul67]

Are you losing oil pressure at high revs , what springs are you running , also what oil , if new lifters are fitted you should fit a cam at the same time, if new cam has been fitted did you drain the oil with the break in compound. There could be some still left in as a friend of mine found out it had blocked some oil ways up.
paul67

[IBM-Tech]

Don't really know if this wonderous mechanic really did on this engine. I can only image. I found enough wrong with the car that I am surprised it runs at all. I know the heads were re-worked and stainless valves were installed. I hope that he put new springs and keepers in.. Can't really tell and he won't tell me as we aren't on best of talking terms now. The lifters are probably stock from the 92 vette. That is why I was wondering if it would be worth my time to get a new set of lifters, Soak them overnight and put them in to solve this valve clatter. I don't think this clattering of rockers or lifters comes into play at high revs.. As it does it at lower revs also. It doesn't do it at idle though, Or maybe it is so low that it can't be heard.

[coolclassiccars]

from what i read,having some motor expreience,sounds like valve ping,ie: ignition timming,knock sensor,compression, my 2 cents.... just trying to help.

[IBM-Tech]

We have checked the timing with the Aldl disconnected and it was right on the money. I have been running a Snap-on Scanner while at idle and am coming up with 0 knock counts. I might want to leave scanner hooked up while under a load to see if I can generate any knock counts that way. I am pretty sure that it isn't a knock issue though. I am looking into either a rocker or lifter or Valve Spring Issue. The Block was boilded before the build, so I know oil passages should be clean.

[paul67]

The reason I said they might be blocked is the paste that used in the breaking in of the cam if a new cam was fitted
paul67

[kamaroman68]

Was the engine rebuilt wit a stock camshaft or did your mechanic maybe put in a solid lifter camshaft? Chris