how often did you spin the car to 7krpms?

 

At the track, and the occasional street race. But I shift at like 6000 not 7000.

 

What I don't get is how the LSJ guys can wind it out even further and more often and not have trouble, but shifting at 6500 and rarily 7k for us is proving problematic. What I possibly found during some logging is that when NLSing at 6300-6500, the RPMs can quickly shoot up to almost 7k during the shifting process (when tuned and cutoff raised to 7k of course).

On the bright side, unlike the superchargers used on the LSJs, the turbo runs out of air up there so it's kinda pointless to go that high except for trying to keep from having to shift in the last part of the quarter mile.

 

Right. I think that I may have a weak valve spring cause it happened on the same one as before. I am going to put on an aftermarket 2 step wot box this winter so the rpms dont jump so fast because I noticed that in a log as well.

 

Interesting... you jsut have to pop the valve cover off to take a look at this right?

 

if the tick only comes every once in a while and you notice it go away it will eventually become permanent as the timing chain tensioner fails. I've had this happen twice now with less than twenty five thousand miles. I also have a second tick that I thought was my lifters and I know lifters on GM cars ticking is somewhat a normal thing except I just thought it would happen down the road in like five years from now. Thanks for the input on the roller. I think that could actually be what it is. It only happens when I cold start it and it goes away just like a lifter does.

 

Well, I think there's a DI sound that similar to what you describe too... a second one. There's a frequent small tick that it always makes and a slightly louder one that comes and goes when it's just idling there or during a cold start.

 

^^^ yes thats normal the noise were referring to you can hear while driving at 60 with windows up and its def nothing you have to search for the noise

so maybe it is a valve issue??

 

I know my problem is the roller again. On the same valve spring as the first one. It is about time to put away for the winter so will do a few things over the winter.

 

why would it happen again though?? i dont know much about them but maybe its the cam?? since its on top of it

 

I think it is a falty weak vavle spring. So when in the high rpms the spring is not keeping tension riding on the cam and is causing it to slap the lobe just right and it breaks.

 

Supporting document... It may be about a different engine, but is just as applicable. Check out the "Boost and Valve Springs Section" http://books.google.com/books?id=Ulv...engine&f=false

As we raise boost through HPTuning, Infiniboost, and/or through hardware, we may need to upgrade our springs, since they weren't made to be used with some of the pressures we're running at.

Just a thought...