5.3 heads and knock
Thread Starter
Teching In
Joined: Dec 2001
Posts: 47
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From: Tarpon Springs FL
5.3 heads and knock I have a 00 WS6 with 5.3L truck heads, 11:1 compression, TR224 cam, LS6 intake, and Ford SVO injectors. Recently at the track with straight 100 octane I was getting 3-4 degrees knock and only 21 deg total timing. Even adjusting the translator very rich would not change the knock.
On the street with 93 octane when cruising at 50MPH and the converter locked, I step into the throttle gladually and I can hear it ping quite a bit. My PCM was done by Ed Wright for this combo.
Today I am going to use top engine clean but it only has 8k miles since the heads and cam. My question is has anyone with these heads had to reduce timing more at partial throttle to get rid of knock??? I need help to figure this one out. There appears to be no exhaust rattle, leaks, or anything else causing false knock and the pinging is clearly from the engine. The heads are from CNC. I have the new truck PVC and oil consumption is minimal. Oil PSI at idle is 43.
On the street with 93 octane when cruising at 50MPH and the converter locked, I step into the throttle gladually and I can hear it ping quite a bit. My PCM was done by Ed Wright for this combo.
Today I am going to use top engine clean but it only has 8k miles since the heads and cam. My question is has anyone with these heads had to reduce timing more at partial throttle to get rid of knock??? I need help to figure this one out. There appears to be no exhaust rattle, leaks, or anything else causing false knock and the pinging is clearly from the engine. The heads are from CNC. I have the new truck PVC and oil consumption is minimal. Oil PSI at idle is 43.
Re: 5.3 heads and knock Bill,
It sounds like you may need to get to a dyno for some A/F tuning. I can't imagine you getting knock with 100 octane and only 11.1:1 compression. Have you had any actual A/F measurements done?
Shane
It sounds like you may need to get to a dyno for some A/F tuning. I can't imagine you getting knock with 100 octane and only 11.1:1 compression. Have you had any actual A/F measurements done?
Shane
Re: 5.3 heads and knock Combo sounds odd.
You can hear it pinging under partial load?
Have you tried to add fuel to the base MAF T?
Are you autotapping?
I would take 'er easy on the car until you get this figured out.
You can hear it pinging under partial load?
Have you tried to add fuel to the base MAF T?
Are you autotapping?
I would take 'er easy on the car until you get this figured out.
Thread Starter
Teching In
Joined: Dec 2001
Posts: 47
Likes: 0
From: Tarpon Springs FL
Re: 5.3 heads and knock Shane-yes it was dynoed with a wide band and everything was fine. This seems to be something new.
John-I just did the top engine clean and will start logging runs this weekend. I did adjust the translator to almost pig rich now and it makes no difference.
John-I just did the top engine clean and will start logging runs this weekend. I did adjust the translator to almost pig rich now and it makes no difference.
