T-56SLPSS

Hi everyone. I just finished building my second 6.0L. The first one lasted 6k then spun a rod bearing. This time its bored 30, forged bottom end, comp 273lr cam, ls6 intake. I busted it off yesterday and there is a chirping every 2nd revolution. There is not a belt on the car and the tranny is not yet in. The chirp sounds like it is coming from the drivers side. anyone know what this could be?

crainholio

iTrader: (2)

A sign that building engines isn't your bag? But seriously, what bearing clearances did you measure at the rods & mains, and how did you measure them?

Jimbo1367

LOL. I would of paid someone after my 1st failure.

87silverbullet

iTrader: (11)

Sounds like you have 2 rods that can be rubbing together. Did you pull all the plugs out and see if you can turn it over with a ratchet by hand to see if there might be some binding?

3pedals

iTrader: (3)

Check and tighten the spark plugs, I have heard a loose plug "chirp" air out on the compression stroke while cranking. just a thaught

crainholio

iTrader: (2)

This is a great point and definitely worth checking.

T-56SLPSS

The first go around i plastic gauged the clearances. This time I had a shop put the bottom end together for me. Rods rubbing would be every revolution not every other right?? I marked the harmonic balancer with white chalk and it does chirp every other revolution. If its every other it has to be exhaust or intake i believe. The lifters are new. My pushrods are comp and are not bent. Rockers tight. I put the plugs in before i put the heads on so i dont see that being an issue but i will check. The motor turns over without binding. would a clogged vacuum line chrip like this? when i turn the motor with the throttle pinned in full flood it chirps too. and its consistent. i will check the plugs tomorrow any other ideas to throw in the pool??

crainholio

iTrader: (2)

If your heads are machined for tapered-base spark plugs and the parts counter guy sold you flat ones, or vice versa, this could cause your chirp even if they're tight.

Che70velle

iTrader: (6)

Maybe push rod diameter too large, rubbing on passage in heads? Aftermarket rockers rubbing inside heads? Just thinking out loud...

parks450

iTrader: (17)

A rocker that isn't getting oil.... Had the exact same thing and I had a collapsed lifter that I couldn't hear.

T-56SLPSS

the pushrods, heads, and plugs are the same ones i had on the last motor and there wasn't a squeak then. could that be the difference in lifters from oreillys for $13.00, and the ones from gm for $ 50.00 ?

T-56SLPSS

its raining today so no work for this guy. i will have time to go give it a look over and i will check everything out and post what i find.

parks450

iTrader: (17)

Take the valve covers off and see if ALL of the rockers are getting oil. I had one that took about 2 mins to get oil even after being warm or just ran

T-56SLPSS

alright guys found the problem. thanks for all the help it was my dumb mistake that made it chirp. i had the problem narrowed down to the drivers side so i pulled the plugs and turned over the motor. the chirp was gone. that narrowed me down to something compression related so i had someone turn the motor while i listened with a hose to try to isolate the problem. when i pulled my hose up to move it to another location i noticed there was gas on the end of it. long story short i had swapped my drivers side head with the passenger and a guide rod stayed in the head with one in the same side of the block so when i torqued the head down it smashed the guide rods off deep in the head and block. luckily the one in the block was exposed about a 1/4 of an inch and i was able to remove it. thanks for all the replys