always faster

iTrader: (6)

For a fully warmed up clip goes to the #23 post.
I really need some help to finally ride the car.Until i will know how to fix it,i ll not drive the car. PLEASE im really beggin right now...


LS6 C5Z Car

Ill try to be clear.My car got a g5x3(234/242--.600/.610) installed last month or so.It was installed with all the parts needed:

-Precision Race Components Double Valve Springs Rated To .675" Lift
-Precision-Machined Titanium Retainers
-Hardened Machined Spring Seats
-New Viton Valve Seals
-Tsp chromoly hardened pushrod
-Harlan sharp rocker 1.7
-Complete ls2 timing chain/sprocket set
-Fast 36 lbs injectors
-ARP Crank bolt
-LS6 oil pump

The car run hard,no knock at all.(gain 82whp and 44wtq).Even before the cam i could here some little piston slap and some slight thicking noise when cold but really nothing major to worry about.At normal operating temp there where no noise at all.But after the dyno session... Damn some new noise are in...

When i start it cold.There is a HUGE Thicking/knocking noise for the first minute.And when i say huge,i mean that i totally wanna turn the engine off because it is scary...it sound like metal on metal...I ve made some check and:

-Oil pressure is good(40 psi warm with Castrol GC 0w30)
-Rocker preload is perfect
-Springs are seated also perfectly
-The thicking get quieter when the engine is fully warmed up but you can still hear it if you pay attention
-I can really make a difference between the new valve noise caused by the stiffer valve springs and the other thciking noise
-Still got no knock on the logger and the car still pull really strong

Right now the car runs on 15w40 oil for some test.I was trying to see if the thicking weold go away but it didnt.I also know now that the oil pump O-ring hasnt been replace because it was looking good.

Thank you all for your help and sorry for my average english.

Here are the 2 clips.Im totally beggin you all for your help.I really need to know what to do or wich way to look because i ll not drive the car t ill im sure that everything is alright.

Cold start inside: http://s799.photobucket.com/albums/y...upknocking.mp4

Cold start engine bay : http://s799.photobucket.com/albums/y...leknocking.mp4

crainholio

iTrader: (2)

Neither video is accessible via the links you posted, maybe use TinyURL instead?

always faster

iTrader: (6)

Sorry about that.Link have been corrected.

KevinR

Not trying to insult you, but did you measure for the correct pushrod length?

always faster

iTrader: (6)

No question is an insult.Each questions and answer get me closer to fix the only problem that i got on this car

The install wasnt done by me.I do know that the guy(friend) didnt measure the pushrod length and put some stock 7.40 directly.Would some longer one would shut up the valvetrain???(7.425 for example)The car got 54 000 miles and the head has never been milled(from what i know).But i ve been searching for the g5x3 base circle to see if it differ from the 19.3mm stocker.


Thanks

KevinR

I would almost bet that's what your problem is.(I could be wrong though) To me, it sounds like valvetrain noise, which can be less noisy with the proper pushrod length. I don't know what length pushrod is needed for that cam, but you can measure to get that figured out. Good luck

KevinR

Hang on, I just read it again....He put the stock pushrods back in? I thought you had some different pushrods from reading your orginal post. If that's the case, you could have a bent pushrod

always faster

iTrader: (6)

How do i measure the correct length for the pushrod?I know that it take some pushrod checker but i just cant understand how and waht do to with it...

He put some TSP chromoly hardened pushrod in stock length.

KevinR

Check this out. I think most of the info is in the cam guide sticky.

https://ls1tech.com/forums/generatio...-question.html

Paul57

The pushrods would be one of the easiest and least expensive things to look at from this point, IMHO. Since your oil pressure is good, hopefully it is not a bearing. How knowledgeable if your buddy on LSx motors?? I believe that base circles on aftermarket cams are typically smaller than stock. I thought stock rod length was 7.425?? Using a 7.4 + smaller base circle could leave the lifters a little low on preload.

Paul57

Take a look at post #10 in here... https://ls1tech.com/forums/generatio...g-machine.html

always faster

iTrader: (6)

Well he put a couple of cam in lsx based car including is own 02 ss wich came with an ls6.He put a ms3 with some 7.4 and since the g5x3 is really close to it he put some 7.4 in mine too.

always faster

iTrader: (6)

This is a clear post, i will have to try it.

But how do i turn my engine to put it in tdc when i can not reach the crank bolt(the steering rack is right in front of the damper...

Paul57

I hope someone will correct me if I am wrong but I am going to go out on a limb here and say this is the stock pushrod 7.421... http://www.summitracing.com/parts/NAL-10238852/
If that is the case and your base circle is smaller than stock (my Crane cam was) then I think there is a good possibility that is your problem.

Paul57

This is another post worth reading. They have different info on here for pushrod length so you will have to take everything with a grain of salt and verify... https://ls1tech.com/forums/generatio...od-length.html
I do seem to remember the base circles being what is stated in post #4...1.53 stock and 1.48 aftermarket. This is diameter though and you need radius so if that is the case then you lost .025" lifter preload (from the cam basecircle).

Paul57

Wow...I did confirm one thing...even GM doesn't know what they are...or at least the people listing the parts on the websites. Here they say the same part number is 7.325...good grief... http://paceperformance.com/i-5131693...010-steel.html

stangtrader

iTrader: (2)

Stockers are supposed to be 7.400" a few of mine measured with a Fowler micrometer were between 7.382-7.386

always faster

iTrader: (6)

Ill take the pass valve cover off tomorrow(quicker one to do) and i will find a cylinder with the two valve shut.I will then measure how many 1/4 of a turn that i get at 22lbs/ft from zero lash and this will guide me if the problem is there or that i need to search somewhere else.

Update tomorrow morning.
Thanks

Paul57

Your numbers are right in line with another thread, the guy was saying he measured stock to be 7.385 also and 7.4 is the closest thing to stock for us (LSx). The dealers/vendors ranged from 7.325 to 7.421 in their descriptions. No wonder people get confused. I don't have a caliper that will measure to that length or I would check mine also. I am going with you guys that did the measuring...7.385.

If you lost .025 with the base circle and gained .015 in a (7.4) pushrod that only leaves you .010 of total preload loss on the lifters. It seems unlikely that it could cause serious valvetrain noise but stranger things have happened, I suppose. Maybe a 7.425 is needed???

stangtrader

iTrader: (2)

I'd unfortunately think this is more of a major issue since it started out of nowhere. I'd pull both covers and check for a loose rocker or broken spring. If all valvetrain is good could be a bearing.I know when I spun one on my ls1 last month I still had the same oil pressure and it was caused cause my stock motor was to worn for 6600 rpm