500@10psi

iTrader: (5)

hi all, just installed new ls7 lifters and hardened prs i expected it to sound bad at first before lifters pumped up but i let it idle to full temp twice and even took it for a little drive and still getting crazy ticking seriously sounds like a deisel. i have great oil pressure idles around 45-50 goes up with rpm still have the stock ls1 cam. i guess my question is can it take a long time for lifters to pump up? and how long is "normal" oh ya also have 7.35 legnth prs
insight greatly apriciated.

butler

7.40 pushrods or get a pr length checker.

Whistler

iTrader: (46)

What's the rest of your setup? (cam, heads, gasket thickness, block deck height) The LS7 lifters will change your preload from the LS1 lifters. They are either too tight or too loose now. You need to get an adjustable pushrod in there and check it out before you damage something.

blazer427X3

Did you soak the lifters in oil before installing them ?

500@10psi

iTrader: (5)

everything is stock no milling stock cam stock valve train execpt the lifters and pushrods i thought this would quiet things down lol

TooLateVTEC

iTrader: (2)

Sounds like theres too much or to little preload on the lifter.

O2Form

try starting it and let it idle for 1/2 hr, that should fill them with oil. DON"T REV IT. You should have soaked the lifters and pumped them full of oil before installing them.

500@10psi

iTrader: (5)

actually did soak them the thing is living 1 hour away from the car it sat installed under load for about a month next time im out there im gonna check for wear and measure pr legnth maybe install the old ones and see what happens

O2Form

I've had trouble like this before and usually letting it idle for a 1/2 or so will get the air out of them.

BAD2000TA

iTrader: (6)

OK - I'm a little confused: why did you change the pushrods and lifters when everything else is stock?

But, the main concern is why did you shorten your pushrods? Stock is roughly 7.40" and you reduced that length quite a bit. I'd go back to the stock length.

500@10psi

iTrader: (5)

one of the lifters failed so i replaced all of them instead of just one. the ls7 lifters are .050 longer so i needed new pushrods

500@10psi

iTrader: (5)

ok checked everything no loose rockers, took 1 1/4 turns to get to 22 ft lbs., so the preload is about 060. its not an isolated noise so i dont have one troublesome lifter. if i let it idle for awhile the noise lessens but doesent go away, also if i shut the car down and start it back up the noise gets worse so the lifters are bleeding down when the car isnt on. maybe i will try putting the old stock prs back in and see what that does. i let the car idle for about an hour and the noise only lessened but didnt go away. any one have any suggestions? really dont want to take the heads back off.....

500@10psi

iTrader: (5)

update..
put the stock pushrods back in and they were actually holding the valves open so being that the new rods are only .038 shorter than the stockers you think maybe i have too long of pushrods. i tried to measure but the adj pushrod i have i cant get to the bottom half to turn it. closest i could get to o lash is 7.30 im at a loss im gonna try changing oil in favor of a thicker oil and inspect o-ring hopefully this does it

muayyadf1

LS7 lifters are noisy, they night need heavier oil to keep pumped up. It's the nature also of after market cams which have aggressive to raise the noise level lobes. Header also is so thin that it can make valves events louder.Put 7.350 push rods and forget it.

500@10psi

iTrader: (5)

So.... turns out that i put the wrong head gaskets on there lol when i ordered the rest of the parts i didnt specify that i had a 6.0 the gaskets are for a 5.7 you guys think this would cause the tick/knock/deisel sound that ive been hearing?... any one have any 6.0 head gaskets they would sell me for shipping??

muayyadf1

Sheesh!

Never expected that...Good luck with the teardown!!

500@10psi

iTrader: (5)

thanks, hopefully that is it. while im in there i will also check everything over just to make sure there isnt something else. this must be some kind of a first, of all the dumb things lol

LilJayV10

iTrader: (39)

Are you going to research this further or just swap the gaskets out? Why did you replace the lifters/pushrods in the first place?

Chris05ssTruck

iTrader: (9)

If you have a 6.0 and you used a 5.7 head gasket, that would make a horrible noise for sure......different bore......don't run it anymore!

500@10psi

iTrader: (5)

im not gonna run it anymore, until i change the gaskets. i am gonna tear it down today and check the gaskets to see how much damage was done, pull all the lifters and inspect. ive had the rockers and push rods out so many times that i know for sure they are 100% i didn't run it for very long so it should all be okay. the reason i changed the lifters is because i had one or more that would tick/ tap once in awhile and it was getting to me. the push rods had to be shorter for the new lifters and i got hardened while i was at it for strength obviously. it makes sense that as the piston comes out of the hole it hits the compressed head gasket compresses it to the head and makes a hellacious sound. note to self ALLWAYS SPECIFY DISPLACEMENT WHEN ORDERING HEAD GASKETS. un freaking believable