: Build complete! problem I cant figure out now...
Finally completed my build.
Added Texas Speed stage 2.5 ported heads, Torquer V2 cam
pacesetter headers,Magnaflow catback
trunion upgrade, ls7 lifters, new pushrods, ls2 timing chain, etc etc
Monsters 18lb flywheel, stage 2.5 clutch
Car runs great, but one major problem. Upon startup and first few minutes of driving the car sounds great, no excessive drivetrain noise. If I get into it "make a pull or drive spirited" it develops a loud ticking. This ticking noise goes away quickly when I stop the car and let it idle.
If I let car cool down for awhile and re-start noise is not there until I get into it again.... ideas? I pulled the valve covers and nothing seems to be hitting anythign it shouldn't. Also replaced header gasket and re-torqued after a few heat cycles.
09-14-13, 03:05 PM
Could be lifter "pump up".
The pushrods might be a little long.
Hard to say when you cam it.
It sounds like its only coming from 1 cylinder though. I figured if pushrods were too long the ticking would be more continuous...?
09-14-13, 04:19 PM
Once the oil heats up and thins out the hydraulics "balance out".
See if your oil pressure at operating temp seems high.
I experienced this with preloads that were a little too much.
My car is just the opposite.
Noisy at start up but quiet after it warms up.
09-15-13, 10:32 AM
It ticks after you get on it and goes away without shutting the car off and letting it idle? What is your oil pressure at higher rpms? Can you get a vid of it doing it when parked?
09-15-13, 01:44 PM
i'd honestly have to hear a video
oil pressure is 30psi at idle and gets up to 40psi in higher rpms.
Yes noise goes away pretty quickly when I park car and let it idle. goes away so quickly it would be hard to get a video, especially with my exhaust...!
Took it to a track day at Mid-Ohio and it was loud enough that my friend could hear it from pit lane as I went by on the straight...
09-15-13, 01:51 PM
That pressure sounds a little on the low side.
Idle I get about 32 lbs. Higher RPM's should rise to almost 60 lbs (roughly 10 lbs per 1000 rpm).
What length pushrods did you use?
Some cams use a smaller base circle to get high lift so the pushrods could be too short also.
just curious, can we rule out detonation?
def. not detonation.
pushrods are 7.3750. Texas Speed originally sent me 7.4000 but after using my pushrods length checker I swapped out the shorter ones.
Thinking I may need to pull the rockers and re-check my preloads.... this was my first time ever doing this so I fear I may have not gotten it right.
just seems odd it would only be making noise on what sounds like one cylinder.
09-15-13, 02:24 PM
What was your oil pressures (idle and high rpm) before?
I use the same heads (not that it matters).
You would be amazed at how much 0.025" makes.
That is why I went adjustable rockers (the only way to go if you want to "dial in" the motor).
09-15-13, 07:37 PM
Usually you need 7.425" pushrods for aftermarket camshafts because the base circle is slightly smaller. Make sure you use the correct pushrod length checker for the model pushrods you are buying. They measure and spec differently between models, even the same brand (i.e. comp magnums measure different than comp hi-tech's).
How far from MidOhio do you live? I'm about 1:30 north and east of there. I could take a listen.
09-15-13, 09:30 PM
I have a similar issue but not near as bad as the op. My pressure is in the 60's top end, and it is not all of the time
My questions is, how much preload should you have? I have 3/4 of a turn on all. Is this on the low side?
09-15-13, 10:04 PM
60 psi is right around "normal".
Over 80 and you can probably kiss the oil pressure sensor goodbye.
09-15-13, 10:21 PM
To clarify, I have 60+ psi on the top end and my noise/ticking doesn't always happen under load and high rpm.
How much preload is needed on a ls motor? I currently have 3/4 or a turn from no lash to fully torqued rocker bolts. This is the same on all rockers. I have heard 1/2 turn to 2 full turns, is this correct?
Heavy, if you have adjustables, how much preload do you have?
09-16-13, 11:43 AM
Preload depends on the lifters.
Generally, most lifters have about 0.125 of travel and 0.065 (1/2) is what is the "norm".
I use Morel's and they don't like a bunch of preload at all.
Just enough to get the plunger off the stop.
0.015 is what I ended up with or 1/4 of a turn as a full turn = 0.050" (Comp Cams #1500 rocker system)
Sounds like i definetly need to pull the rockers and check the pushord length/preload... Will try to do this over the weekend.
Next question is, will I hurt anything in the meen time?? or just sound like a P.O.S. driving around for now...
09-16-13, 07:21 PM
I wouldn't go play romp um stomp um till I had it right.
You could swap out all the pushrods in less then two hours and a six pack (after the job).