Well i took it apart and had a loose lifter. Took it off and checked the pushrod and it wasn't bent. Being confused on why it loosened up i put it bac together and tightened it down put it together and starteed it up and guess what. It ran awesome for about 8 blocks then went back to making the same sound. What gives?
I took the valve cover off and crank the motor and all rockers move.
checked all the pushrods and they are as straight as an arrow, the rockers are all good and theres no stripped bolt.
I tried checking the push rods by pushing down on them to see if the lifters gave out but they didn't Could it still be a bad lifter?

This is all the general info I have from a post i made on LS1tech. Anyone have an idea or suggestion?

 

Can it be chocked up to the standard LS1 piston slap?

 

If after running it you opened it up and the rocker was loose then you have a junk lifter that is collapsing.
The bad part is that you have to pull the heads to change them out.
The good part is that you can get a set of new replacment lifters , which are the upgraded lifter, for low dollars at SDPC.

 

I bought a set of the newer style LS7 lifters from my local GM dealer for just under $110 with tax. But be warned, their plunger depth is raised slightly over the original lifters, so you will need to check pushrod length again.

 

Agreed. Collapsing lifter. Good idea on running the stock rockers. You can never worry about setting lash incorrectly.

Mike

 

So pretty much it's agreed t's a collapsed lifter and the f*cking head has to be pulled off to get to it. Just great
Well since i already have the valve cover off, the rockers, and push rods out shouldn't be too bad to take it to someone.
You guys think it be okay jus to replace the one bad one or should I do em all?

 

I don't believe you can buy the original LS1 lifter anymore. You can only get the service replacements, which are the LS7 style. They may require a different pushrod length, depending upon your original setup. If the lifters were preloaded too light before, they may still work. I would recommend replacing them all, but that's up to you.

 

Honestly if you have a high $$$ setup like that, you should have been using the Morel lifters from the start.

 

I bought the car with this setup and was suprised to find out they were stock lifters after i talked to him when the noise appeared.

 

pushrod numbers are 4703 and 7.400
do you know what length the ls7 ones require?

 

SDPC?

 

SDPC = Scoggin-Dickey Performance Center www.sdpc2000.com

Pushrod length is determined by much more than just the lifter. If you run the EXACT same setup as any I've run, I can tell you what length you need. Otherwise, you MUST measure yourself.

 

Thanks,
Car is getting the head pulled off today hopefully so I'll know the exact problem soon.