valve lash and knocks.

[Deadphishy]

So i am in the process of tuning my car, and im getting a lot of knocks right after vtec crosses, and now in the higher rpms. I dont hear or feel the knocks and they happen really fast, about 100 in a single pull. The are also unaffected by removing timing. So we are thinking its valve train chatter. is this common?

im goin to redo my lash today and see if it helps. does anyone have any special tips?
since clearly i didnt do it right the first time when the motor was still on the stand.

ps, the chatter is pretty loud at idle. between the high compression pops and the valvetrain my car sounds like a little desiel tracktor.

[Drew1d]

So i am in the process of tuning my car, and im getting a lot of knocks right after vtec crosses, and now in the higher rpms. I dont hear or feel the knocks and they happen really fast, about 100 in a single pull. The are also unaffected by removing timing. So we are thinking its valve train chatter. is this common?

im goin to redo my lash today and see if it helps. does anyone have any special tips?
since clearly i didnt do it right the first time when the motor was still on the stand.

ps, the chatter is pretty loud at idle. between the high compression pops and the valvetrain my car sounds like a little desiel tracktor.

The valvetrain is loud in these cars. Some switch to a 5w30 to quiet it down. Good luck with setting the lash.

[FoReVaPmP]

When was the last time you did a valve adjustment????

[Deadphishy]

motor has 1300 miles on it. Valve lash was set when i put the head together.

[talonXracer]

You dont only pull timing to reduce knock. You also can add some fuel, and sometimes it is only this cooling affect that will reduce knocks.

What valve train did you use again?

[davisj3537]

You dont only pull timing to reduce knock. You also can add some fuel, and sometimes it is only this cooling affect that will reduce knocks.

What valve train did you use again?

X2:mwink:

[Deadphishy]

its all stock 2003 type s stuff. except the head casting and valves. they are TSX.

[Deadphishy]

I added a data log to the first post.

[talonXracer]

Have you checked the valve lash yet? I usually see a need for a lash adjustment during/after the engine/cam break-in period.

[Deadphishy]

Ok i just got her popped open. the motor is still pretty warm/hot not scolding or anything but hot. And the lash for cyl 1, intake side was at .014" and exhaust .016". So when it cools a little more i'm expecting even more.

[kon]

You should hear what my motor sounds like durring idle, loud!!! I get an average of 28-50 knocks in a third gear pull and nothing I do reduces the knock count. I've pulled up to 6 degrees of timing, going from 25 degrees to 19 degrees and nothing. I've tried being at 12.8:1 and 13.5:1 AF and no difference. I'm currently running 24 degrees of timing advance and I still get ghost knock. K2's with pro series valvetrain will do this everytime.

[talonXracer]

I have heard alot of pro series valve trains that did create alot of ghost knock. I also had alot of ghost knock with the EVS and TI retainers, removed the ti and the knocks were almost gone.

But with the amount of hot lash he has I am sure the lash will end up being the issue.

[Deadphishy]

Well I finished doing the valve Job. Car actually runs smoother! stronger and quieter. Havn't had a chance to do any pulls but from what i'm seeing around town. (1 knock in 10 miles) My problem might be solved. We shall find out after rush hour if it isn't raining.

[talonXracer]

Excessive clearance=less cam lift and duration=less power

Excessive clearance=more wear

Excessive clearance=more noise

[Deadphishy]

Excessive clearance=less cam lift and duration=less power

Excessive clearance=more wear

Excessive clearance=more noise


went from 100 down to 20 knocks. per pull. much much better:mbiggrin:

[talonXracer]

Now you may see some kind of impact with timing or/and fuel adjustment and the remaining knocks, or not. But that is a good decrease in knock count!

[Slip_Angle]

Sorry to threadjack but how hard is it to adjust valve lash? How long should it take?

I think my K24a2 would benefit from a good adjustment.

[Deadphishy]

Sorry to threadjack but how hard is it to adjust valve lash? How long should it take?

I think my K24a2 would benefit from a good adjustment.

2 hours to let the motor cool and about an hour to actually do the valve job. depending on how fast you want to go.

[Slip_Angle]

Post your calibration as well.