Stock ZR1 KR, extended log included

[Alvin]

I'll echo what Ed is saying.

Everything shows knock.. If it doesn't it likely has bad knock sensors. Just about every stock LT4 I do knocks it's ass off on the stock tune.

[SPG1]

Well this is an LS9, not an LT4. LT4s and especially LT5s will knock unless on 100 if it?s warm out. They have even worse heat soak. Higher compression. But we have the opposite issue here.

I don?t have any credits, never had intentions of tuning myself. That was for a tuner on a dyno. They told me they would check for any issues before any changes were made, including burst knock and all that.

I?ve got people saying 30-40 whp can be gained by cleaning things up, then I?ve got others saying this amount of KR is serious and don?t drive it, now I?ve got people saying don?t touch it.

Nothing more needs to be said in this thread. I?ve wasted enough people?s times. It?s being sold. Lock please.

[abc]

It's post's like the above that remind me how unreasonable the general public can be. I bet you pro's love tuning for guys like this. Que the crystal ball I guess...

[Alvin]

I'm fully aware your car is a LS9.

Everything knocks. If there is no knock the sensors are bad or it's crazy detuned. my point was the LT4's knock a crazy amount stock.

[edcmat-l1]

It's post's like the above that remind me how unreasonable the general public can be. I bet you pro's love tuning for guys like this. Que the crystal ball I guess...

Done!

businessman-looking-into-crystal-ball.jpg

[edcmat-l1]

Well this is an LS9, not an LT4. LT4s and especially LT5s will knock unless on 100 if it?s warm out. They have even worse heat soak. Higher compression. But we have the opposite issue here.

I don?t have any credits, never had intentions of tuning myself. That was for a tuner on a dyno. They told me they would check for any issues before any changes were made, including burst knock and all that.

I?ve got people saying 30-40 whp can be gained by cleaning things up, then I?ve got others saying this amount of KR is serious and don?t drive it, now I?ve got people saying don?t touch it.

Nothing more needs to be said in this thread. I?ve wasted enough people?s times. It?s being sold. Lock please.

That's a little over the top don't ya think?

[SPG1]

I, too, thought I was being unreasonable. So I figured for shits and giggles I'd pull the plugs before I finalize everything. My suspicions confirmed. They're alarmingly clean for 9,000 miles, and full of black peppering and marks in various levels of severity, considering how much I've tried to avoid inducing the condition. I'm given to understand this is from detonation blowing the carbon off the pistons. The camera doesn't pick it up well, but two plugs are very clearly full of it. Turns out the single tap noise I'd randomly hear under load might've been knock. Oh well. Had to upload the photos to imgur as the forum said a jpeg is an invalid image. The camera had some difficulty showing the marks, but they are there. Any last ideas? 1 step colder NGK TR7IX or Denso IT22 that people seem to run on these things? I’m not sure.

https://imgur.com/a/eJEqa0z

the plug with the most stuff on it is cylinder 8, backmost on the passenger side

It seems the Z06 and ZR1 share the 41-104 plugs which is heat range 6. NGK says 1 step colder per 10 lbs of boost. I have 10.5 lbs. it is possible all I need is a colder plug and just leave it stock? Maybe then datalog it again? And what gap to run? The factory .040? If that actually solves the problem I’ll never touch it again. I don’t need or want more power. I just get nervous when something knocks. Leave the safeguards.

[abc]

Well here goes... If it were mine I would pull 2 degrees at a time in the problem areas and continue to monitor, that's assuming I couldn't put more knock resistant fuel in it. With the amount of sign yours is showing it will live past the warranty period.

[Alvin]

Knock will show up as a liittle metallic looking balls on the porcelain. Black spots aren't knock.

[abc]

Knock will show up as a liittle metallic looking balls on the porcelain. Black spots aren't knock.

I'm no expert on the subject but, many experts will disagree with you. I can't seem to find the NGK study right now but there are many lesser known articles out there like this one:

http://www.wallaceracing.com/plug-reading-lm.html

Although I have noticed several of the largest manufactures will say the black spots may or may not be signs of knock. In my experience, I have been able to back the timing down and in result the black specs disappear.

[SPG1]

Well here goes... If it were mine I would pull 2 degrees at a time in the problem areas and continue to monitor, that's assuming I couldn't put more knock resistant fuel in it. With the amount of sign yours is showing it will live past the warranty period.

Yes, it doesn’t look overly serious considering these plugs have about 9,000 miles on them, a couple top speed-ish runs to 170 and 190, and multiple 3-4 pulls at events, but I’d like to eliminate it entirely. This doesn’t occur in the summer. This is strictly a colder temp problem. The colder denser air in the winter plus the more aggressive spark adder table for colder IAT is contributing.

[edcmat-l1]

That plug looks fine. As Alvin said black specs aren't knock. Any and all late model vehicles are going to have plugs that look like that. 100% normal.

[SPG1]

Well it seems this story will not have a happy ending. Put in the colder plugs today, one of my FireCore wires broke in the process. That what a bad omen.

3 cylinders on the drivers side appear to have mounds of something on them. And every single cylinder wall has vertical scoring in what appears to be the same spot. Shows up as black streaks on the borescope in the worst of it. Weird thing is the crosshatching is somewhat visible through it?

Either way I think my not even 20,000 mile LS9 is toast.

[edcmat-l1]

Well it seems this story will not have a happy ending. Put in the colder plugs today, one of my FireCore wires broke in the process. That what a bad omen.

3 cylinders on the drivers side appear to have mounds of something on them. And every single cylinder wall has vertical scoring in what appears to be the same spot. Shows up as black streaks on the borescope in the worst of it. Weird thing is the crosshatching is somewhat visible through it?

Either way I think my not even 20,000 mile LS9 is toast.

What happened in the past week?

I, too, thought I was being unreasonable. So I figured for shits and giggles I'd pull the plugs before I finalize everything. My suspicions confirmed. They're alarmingly clean for 9,000 miles,

When you posted this ^^^ a week ago they all looked fine.

Can you post pictures of the 3 cylinders that are goobered up?

Have you done a leakdown test on it?

[SPG1]

What happened in the past week?



When you posted this ^^^ a week ago they all looked fine.

Can you post pictures of the 3 cylinders that are goobered up?

Have you done a leakdown test on it?

It hasn?t been driven and we didn?t borescope the cylinders. Today we put the colder Denso plugs in and decided to see if there was any evidence of knock. What I found was 3 pistons with a mound of crap on them and what appears to be scoring and black streaks on the walls. Some cross hatching might be visible. It looks horrendous. I don?t have a leak down tester. I don?t burn oil so none of this makes any sense.

[edcmat-l1]

It hasn?t been driven and we didn?t borescope the cylinders. Today we put the colder Denso plugs in and decided to see if there was any evidence of knock. What I found was 3 pistons with a mound of crap on them and what appears to be scoring and black streaks on the walls. Some cross hatching might be visible. It looks horrendous. I don?t have a leak down tester. I don?t burn oil so none of this makes any sense.

And combined with what the plugs look like, doesn't make sense to me either.

Can you take pictures with your bore scope?

Need to buy or rent a leak down tester.

I'm thinking maybe you're seeing things incorrectly. Or, what you're seeing isn't what you think it is.

All of the pistons should have some carbon build up on them. They're not going to be clean like the spark plugs.

Pictures sure would help here.

[abc]

The only problem I'm seeing right now is you have at least one broken spark plug wire. Put the stock ones back on or buy a new set of NGK wires and run it.

I believe if you do the same inspection to 100 of the same cars you will see 99 of them look like yours.

The pro's have mentioned all of these combos. like yours have KR. The signs you have mentioned are normal for what you have described. If it were mine, I would pull some timing from the modifier table, monitor the logs, and enjoy it.

If you can post the pics from scoping it, we may be able to give more insight.

[SPG1]

The only problem I'm seeing right now is you have at least one broken spark plug wire. Put the stock ones back on or buy a new set of NGK wires and run it.

I believe if you do the same inspection to 100 of the same cars you will see 99 of them look like yours.

The pro's have mentioned all of these combos. like yours have KR. The signs you have mentioned are normal for what you have described. If it were mine, I would pull some timing from the modifier table, monitor the logs, and enjoy it.

If you can post the pics from scoping it, we may be able to give more insight.

And combined with what the plugs look like, doesn't make sense to me either.

Can you take pictures with your bore scope?

Need to buy or rent a leak down tester.

I'm thinking maybe you're seeing things incorrectly. Or, what you're seeing isn't what you think it is.

All of the pistons should have some carbon build up on them. They're not going to be clean like the spark plugs.

Pictures sure would help here.

This is as good as we can get for right now. The borescope doesn't swivel. And of course I can't get the really bad spots to show, they were twice the size of this.

The forum just tells me my files are all invalid so I had to upload to imgur: https://imgur.com/a/tFYFXsM

[SPG1]

I ordered a Depstech DS630DL. Dual lens articulating endoscope. I?ll get better photos during the weekend.

[SPG1]

I love this borescope. I stuck it down all 8 cylinders. Ideally I should slightly rotate the engine to get a complete look, but I'm not sure that's necessary judging by my findings. I took 45 images, and I believe I am seeing normal wear. Could any of you confirm? I'm gonna kick myself if I was upset over nothing. I'm sorry.

Here's the imgur album with 45 photos. I started with cylinder 8 and worked my way around. There might be a few duplicate photos, probably main lens vs side lens showing what the light does to the marks and crosshatching.

https://imgur.com/a/3OVryDT