Got my engine running and I have been breaking it in. I have driven for 3 10 minute periods giving it hell but not beating on it. First gear is useless and 2nd breaks loose bad.

Power is insane, but I have a few problems.

I never previously had knock retard but now I do. Readings bounce around up to 7 a great deal. I currently have my 1.6 pro-mags set at 1/8" past zero lash. I have run them as tight as 1/2 turn past zero lash. They definitely have more tick so I think I will tighten them up some. I do have the LT4 KM.
What do you guys think for my valve lash with my setup?

The engine idles at start up but when you are driving and come to a stop it wants to die. I am currently running Ion's tune as well. I will be dyno tuning the car once the KR and this idle problem when stopping is in check.
What do you guys think is causing this?

 

We would really need to see some scan readings/values before we could make an accurate recommendation. O2, Long Term Fuel Trims, MAP, MAF, TPS, IAC counts, etc.

 

The dyno tune should fix the knock retard and idle problem.

 

What do you guys think about may valve lash?

 

The hydraulics are usually fine with anywhere between 1/8 turn and 1/2 turn.

 

In the end I paid Speed Inc. to set my lifters, what a difference. I asked if 0 lash to a 1/16 is the way they would go and they said yes. They have to be set correctly or your missing out on some HP. Good luck.

 

Yea, Zero lash (to 1/16th turn preload) made the most power on mine for sure......any more preload added would just pump up at higher RPM causing the valves to be off of their seats when they should be closed(killed power)........After my mods, mine would idle pretty good as well, but when comming to a stop it would nearly die because the RPM's would drop so low....this was "fully" corrected on on mine by drilling my throttle bodys IAC hole out a bit bigger.....what "exact" throttle body are you running?........Joe

 

I have a 52mm ported stock throttle body. Do you have an idea of what the final size of the hole ended up being?

I may need to adjust the rockers with the engine running, I am very concerned about the knock. Unless it was my imagination, I think I even heard it a few times.

 

knock sensors can eb triggered by exhaust leaks, typical noise from headers, low power steering fluid, loose/rattling motor mounts, roller rockers, etc, etc.

It could be ANY of these or a combination of these OR the engine could actually be having "knock" due to low octane fuel, too much timing or lean A/F ratio.

Lloyd

 

Thanks Lloyd,
I am runing the same headers I had before, they caused no knock then. Definitely no leaks thanks to the locking bolts. Power steering is full. Poly mounts re tight as hell. I am leaning toward the rockers or maybe the 5 month old gas.

I want to get the engine stable and broke in as possible before the dno tune.
What is your take on the engine trying to die when coming to a stop?

 

If you have a stock ported TB, I don't think that's your issue.

 

lt4 knock module should take care of the knock retard.

 

I was getting knock retard out of the *** with my pcmforless tune (sometimes 15 degrees), and since I got a dyno tune by Jeremy Formato I haven't gotten knock retard since. And I'm running a scanmaster so I see the knock retard all the time.

 

I think you're on to something.

 

Great to hear that you are up and running.
And as mentioned above, make sure she gets fresh fuel

I had a bunch of false-knock-induced retard as well before I had Ed fix that for me in the tune.

As for rockers, I've noticed that quieter does not always mean more HP.
Going past 1/8 will likely cause you more harm than good.

I adjusted my idle with the throttle stop screw on my TB.
Others have drilled holes to induce a small "leak".
Others just bend the tab that bumps up against the stop with a pair of pliers.