Well , I hurt the old stock bottom end. It's a 2002 LQ9 from an Escalade I swapped into my '71 Camaro. I put a little over 300 miles on it before the final tune was done. I enjoyed the performance , but I thought the set up should have been more . Cam/243 TEA heads, long tubes,4l60e and 3.42 rear. After the tune I was blown away with the increased power/performance. Sooooo today I decided to take it out for a quick spin. At 30mph I quickly put the pedal to the floor and the car spun the tires . I was surprised the tires lit up, so naturally I tried it again to prove to myself it really happened. It did it again. Needless to say I was impressed and very happy until I got home. Pulling up to the garage door I could hear the engine was making a tapping noise. It is just as loud under the hood as from under the car.
Did I hurt the stock bottom end? The top of the engine has new lifters, 11/32" - .120" wall Manton pushrods. The heads were CNC'd 243's by TEA . They set the springs up for the camshaft.
I don't know what rpm the engine spun up to. I installed a Dakota digital RTX dash and set the rpm warning horn(which did alarm) to 6400. I didn't think it would get hurt spinning it a couple hundred over the alarm.
Any input ? Check the upper side of the engine for trouble, then if no problem found , look at bearings ?

 

Tapping isn't bearings. Likely valvetrain related. Pull the valve covers, start it, and see where it is coming from.

 

Ok, that's were I will start. It is definitely the easiest place to start. Do you think a lifter might have gone out?

 

Even though they're new, it IS possible. Look for broken spring(s) too, or bent pushrod(s)

 

Better not be bent pushrods. I spent "good" money on them. I set the lifter preload between .053 -.065. The springs are PAC-1904. Anyone ever have any issues with these springs?

 

Maybe a rocker arm worked loose.

 

If a valve hit a piston, its not the pushrod's fault.

 

Better them than parts that cost a lot more...

 

Look over the valve springs very carefully, a broken spring can be missed by a quick look over. Also, spin the motor to DTC of the compression stroke on cylinder #1, then wiggle the rocker arms. Turn the crank 90 degrees then go to the next one in the firing order. Check for a loose rocker.

 

Hopefully, it's minor like a loose rocker.

 

Thanks for all the replies . Today I had some time to look into the noise. with #3 intake and exhaust on base circle I was able to push down the pushrod end of the rocker depressing the lifter and slide in a .008 feeler gauge. #4 exhaust had over.130 movement. I loosened the rocker bolts and retorqued them to 22 ftlbs. That actually reduced the amount of play.
I started the engine and most of the noise was gone. I drove it up the road and back but not any rpm to speak of, just slight ticking/tapping
I think I probably should/need to change the lifters. I purchased "white box" "bulk" LS7 lifters when I put the engine together. Lesson learned!!! Maybe the lifters were actually Chinese knock-offs!

 

Tapping/ticking can absolutely be a bearing it happened to me. Did the lifters over and sound didn't go away. Ended up being a bad rod bearing.

 

Agreed. The key to help determining the source of a knock or tap location, is the speed or rhythm of the noise in conjunction with idle speed. A bottom end sound will be in rhythm with idle while a top end noise will only be half speed because the camshaft is turning 50% of crank speed.
I’ve heard plenty of rod bearings tick or tap as they start to come apart. Once the rod bearing spins for a few seconds and dissolves basically, the noise will turn to a knock.

 

Could it be leaking header gasket?