Raced my father in law the other day and after, I had this taping noise. I did not miss a gear and I was shifting around 6800 rpm. Motor has king bearings, scat rods, mahle pistons, Johnson short travel link bar lifters, custom length manton pushrods, Mamo custom spec cam, Mamo 223 sportsman heads, dual springs, yella terra rockers. The sound seems to be coming from the passenger side. I did remove both valve covers and look at everything, everything looked good. I need to take them off and dig into more. Motor has about 1k miles on top end build and maybe 8k on lower . Yes the valve noise has always been that loud.

 

If you mean that sound when you play with the RPM and not the background valve train noise, that almost sounds like something vibrating. The noise doesn't seem to correlate with engine speed, which a lifter would.

There is an EVAP valve on the driver's side right in the middle, is that the source of the noise?

Have you checked with a stethoscope, you can buy one fairly cheap at the auto stores.

 

yes the noise when playing with the rpms. Ill have to check the EVAP valve. You think it would be vibrating against the intake or something? I need to get a stethoscope, I have not checked with that yet. The noise is pretty loud I can hear it eco while driving it and it also seemed to show up once the car was at operating temps. The night it did it, it stopped after I let it cool down and drove it back home. I feel like it could be something vibrating as well, guess I need to get a stethoscope and start looking.

 

!st thing I would look carefully at are the valve springs and check all the push rods for preload. Sounds like something in the valve train just need to find it before it breaks badly.

 

when you say check push rods for preload, do you mean check for zero lash? when i built the motor every push rod was a custom length to have preload set to johnsons specs, i believe it was around 30.

 

What I meant was be sure the preload hasn't changed drastically on one or 2 valves indicating a big problem with a lifter etc.

 

What he said!

 

 

I found a lose plug wire and exhaust leak while pulling the head. Lifters are good. I talked to Mr mamo and he recommended to check rod bearings so now the motor will be coming out. Looking at the piston and head, looks to be getting close, no scaring or damage though.

 

Something big going on there for sure. Now that I see the piston you can certainly hear it hitting the cylinder head in your video. Weird but I have a similar noise that has me worried. I'm sure its a piston noise and it started after a hard run. My noise is at part light throttle accelerating sounds very much like yours. If I load it harder it goes away, almost has to be piston to cylinder related. I also noticed if I run the engine hard and clean it out its not as loud. Sure costs to play.

 

Something I wish I would of done this time that I did before was get a pry bar and pry on the headers. I had a exhaust leak before that sound like a tap and pryed on the headers and it went away. Changed the gaskets/fixed the exhaust leak and it was gone... Main reason I didn't do that this time is I had metal in the oil.

 

I found my noise....its the check valves for the AIR system making noise at part throttle. Pisser

 

Unless legally required to pass smog, rip that crap out post-haste....

 

Gotta be a spun rod bearing for it to hit the head. Sucks!!

 

brandon 6.0 you are correct... pulled the motor and the piston that was hitting had a spun rod bearing.... now the decision to go 383 stroker or just go back with stock stroke

 

I was gonna say rod bearing because the noise is a "heavy" clunk, thunk, thack, sound. It's heavier than the lifter sound you hear. When I listen for noises I listen for how heavy the sound, sounds, to try to determine the source.

Sucks that happened after a recent build. And at 6800 you shouldn't have stretched a rod bolt that would have let go of the bearing so that makes me think something went wrong with assembly. Maybe contact whoever built it and ask for help with the bottom end build. If you were low on oil or on old oil that may have contributed but if you were spot on on your oil and only going to 6800 then this shouldn't have happened I'd be talking to my builder.

 

well i sent the block crank and rods to the shop... then a friend of mine had a ls3 long block for sale so i picked it up... about to sell the ls1 and start on the swap!