2000Hawk#317

iTrader: (3)

So I live in Raeford and there is no one in the area with LS1 motors so no help out here. Anyways: I have a 2000 Firehawk and was racing a RS4. Lost but kept up. I ended up spinning a bearing, bending a push rod, and notching one piston. I finally was able to build my motor after 7 months. Got it done last night and I have the same sound ish. I put new bearings, seals, rings, and gaskets. sent the motor out to get a once over. The crank got re-serfaced and i had to put 30 over bearings on the rods, and 10 over on the mains. Everything is by the books when it came to this build. I am using Royal Purple synth. 5w30. With a 60 PSI pump. Im lost....Any advice?

2000Hawk#317

iTrader: (3)

I also did plasti-gauge all the bearings.

StryfeS13

iTrader: (2)

Can it be a push rod making the noise?

http://www.youtube.com/watch?v=J61swhg1ZMM

2000Hawk#317

iTrader: (3)

could be. I know they're not new but i replaced my 130,000 mile rods with 30,000 rods. maybe i should spare the 130 or so to get new ones and stop being lazy. Did it turn out to be rods on that car?

JaYZeig

iTrader: (11)

i honostly think thats too hard of a noise to be a pushrod..hate to say it but id look back into the bottom end.

parks450

iTrader: (17)

Get a mechanics stethoscope and see if you can pin point the "knock". Does it go away when warmed up or increase with rpms?

2000Hawk#317

iTrader: (3)

Thats not my car but i will try to up load a clip. maybe that will help. do you have advice that may be helpful as far as my situation?

97badass

iTrader: (8)

What assembly lube did you use? And I would not have used synthetic oil to begin with on a new motor

redsilv

He said synthetic oil!
There is a thread thats been getting sillier by the day about that!!
LOL

GMtechmatt

dude that a hard knock id do a power balance test to eliminate bottem end.

2000Hawk#317

iTrader: (3)

i used CRC assembly lube with molygraphite. i didnt want to start mixed synth. with regular. whats the difference in using it in brand new cars with no miles compared to a rebuilt motor with 130,000 miles?

2000Hawk#317

iTrader: (3)

redsilv.... what do you think on synthetic oils for break ins?

redsilv

This is totally my opinion,
I have found out from my younger years that using the recommended lubricant as specified is a good idea. I have done a head cam change and didnt use the recommended moly type lube on the cam and wiped out my lobes on my lunati
cam. So for reassurance i will always be using recommended lubricant from now on.
Now after break in period that is when i would run the synthetic to help keep friction down. Rings are seated and bearings are mated. All is good for metal to metal contact for many miles hopefully
I also believe that all car manufac. start those motors at the factory before they hookup the speedo. i guess. somehow gm has to test that rpm limiter ! lol
I believe that any car producer will break an engine in to seat the rings and bearings. They would have alot od warranty issues with all of those crazy people
out in the world
That is MY OPINION
Maybe im highly opinionated?

redsilv

Is your oil pressure good at idle?
You seem pretty confident about bearing clearances. Is it a knock or tick?
Did you hone the cylinder walls and re-install the origanal pistons?
Piston slap?
A fine cracked flex plate will put nitemares in your head but that was a ticking for me.
If you start the engine and put your hand on the bottom of the block you can feel a loose rod bearing. (I had too many beers one night)

Post a sound clip

redsilv

One more suggestion
Are you certain its a mechanical issue?
Done anything to the ecm?

Sound clip?
Be your best bet for the guys on this forum. There is some knowlegable guys on here that could guess better than me im sure

wildcamaro

iTrader: (15)

I hope you didn't use royal purple on break in!

chrisfrost

iTrader: (8)

Wow ,,,,,,.030" under rod journals ,,,,,,,,,,,I've never been a fan of undersizing crank journals but I suppose if done right no problem

bjamick

iTrader: (31)

I had my rods turned .030 and my mains turned .010, no problems here after multiple 7k rpms. At around 3k miles on the rebuild or more.

As long as you get the correct bearings and do the correct torque procedures, then there should be no problem.

Oh and just for knowledge, a .030 turned crank on rods on an ls1 crank makes it the exact same size as a standard SBC 350 rod bearing.

remauto1187

iTrader: (1)

Doesnt have the rat-tat-tat sound of rod bearing problem and doesnt have the growling of a main bearing problem either. Typically a valvetrain problem would have more of a rat-tat-tat sound similiar to a rod knocking as the engine winds down off a higher RPM. Sounds alot more like an exhaust leak or possibly like someone else mentioned a cracked flywheel. I noticed upon revving the engine as it wound down there was exhaust smoke coming up the drivers side of the motor. A little mini cloud!

Check all the exhaust manifolds for leaks and where the exhaust connects too before you going yanking the engine apart! Inspect that flywheel/ring gear also.

I honestly dont believe to be a serious internal engine problem with the info given and what the video/audio shows.

eric1h

iTrader: (7)

disconnect the spark plug wires one at a time and see if the knock quiets down on any one cyl. if it does then it's probably knock. sounds to me like piston slap.