LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Another Knock issue

Thread Tools
 
Search this Thread
 
Old Mar 31, 2006 | 05:11 AM
  #1  
Honda Hunter's Avatar
Thread Starter
Registered User
 
Joined: Sep 2005
Posts: 2,271
From: Bahrain
Another Knock issue

I need more opinions. Last night I poured in another bottle of torco fuel addative to less than half a tank a fuel which half a tank is 8-10 gallons I think. According to the torco instructions that shouldve been enough to equal 100+ octane. At first it seemed like the knock had went away or at least not as much but once I got on it I still got the same 5.0 degrees of knock. Only difference between now is with the addative I dont see knock as fast as I see it without the addative. It's starting to become confusing for me. What's confusing is why does the addative seem to help a little then show the same amount of knock, mabey 1 degree less than without the addative? If it still had the same amount knock I would say false knock but it seems to help which in the end leads me to think there is a lot false knock and mabey 1-1.5 degrees of real knock. What do you guys think?
Old Apr 1, 2006 | 12:54 PM
  #2  
Honda Hunter's Avatar
Thread Starter
Registered User
 
Joined: Sep 2005
Posts: 2,271
From: Bahrain
Re: Another Knock issue

update


I put re filled the tank without octane booster and now I see at random .5 - 2.5 at part through part throttle and 5.0-6.0 at 95%. All I want to know is from what Ive wrote does anyone think it's still false knock or real?
Old Apr 1, 2006 | 01:03 PM
  #3  
djkyle25's Avatar
Registered User
 
Joined: Apr 2006
Posts: 12
Re: Another Knock issue

sorry to go off topic, but how are u measuring knock, u got a sesnor? and if so how much and where do i get them
Old Apr 1, 2006 | 01:10 PM
  #4  
Honda Hunter's Avatar
Thread Starter
Registered User
 
Joined: Sep 2005
Posts: 2,271
From: Bahrain
Re: Another Knock issue

I have a Scanmaster. All cars should have it, it's great.
Old Apr 1, 2006 | 02:51 PM
  #5  
Digital Designs's Avatar
Registered User
 
Joined: May 2004
Posts: 167
From: Shawnee Oklahoma
Re: Another Knock issue

yes indeed diagnostic scanners are great, i have a snap-on portable unit. but if you want to make sure its not real knock retard, take the sensor out wrap the threads in a couple layers of teflon then re-install it. if the knock goes down a little bit then its false knock
Old Apr 1, 2006 | 08:21 PM
  #6  
Fbody1's Avatar
Registered User
 
Joined: Feb 2000
Posts: 363
From: fl,jax
Re: Another Knock issue

what does it say that the torco fuel additive boost the octane to ? how many points? if you are seeing a differnce when adding octane it is probably not false knock . also what comp ratio are you at ? and what dynamic c/r ? and what octane are you blending with the additive?

Last edited by Fbody1; Apr 1, 2006 at 08:25 PM.
Old Apr 1, 2006 | 09:59 PM
  #7  
Honda Hunter's Avatar
Thread Starter
Registered User
 
Joined: Sep 2005
Posts: 2,271
From: Bahrain
Re: Another Knock issue

With 10 gallons of fuel using 93 octane it should be 107. I'm using something like 89 mabey 91 octane. So I figure it's around 103 with the addative. Even with the addative I still see the same amount of knock just it comes later, and not at the lower rpms like it does without. My comp ratio I believe is in the low 12's. I'm not sure what my dcr and scr is. I need to figure that out today.
Old Apr 1, 2006 | 10:21 PM
  #8  
smoknta's Avatar
Registered User
 
Joined: Dec 2003
Posts: 441
Re: Another Knock issue

Originally Posted by Digital Designs
yes indeed diagnostic scanners are great, i have a snap-on portable unit. but if you want to make sure its not real knock retard, take the sensor out wrap the threads in a couple layers of teflon then re-install it. if the knock goes down a little bit then its false knock
By wrapping the threads with teflon tape, you are basically desensitizing the sensor. So either way, if it is false or real knock, it should go down with this method.
Old Apr 1, 2006 | 11:40 PM
  #9  
Digital Designs's Avatar
Registered User
 
Joined: May 2004
Posts: 167
From: Shawnee Oklahoma
Re: Another Knock issue

if it was reinstalled without doing this step in the engine rebuild, it will be alot more sensitive
Old Apr 2, 2006 | 04:59 AM
  #10  
sssalah's Avatar
Registered User
 
Joined: Nov 2001
Posts: 1,152
From: Bahrain
Re: Another Knock issue

The static CR is 12.23:1, with 5 cc pistons, a 0.039" gasket and assuming 55 cc chambers on the resurfaced AFR heads.
The IVC at 74 deg ABDC so that should put the DCR at 9.01:1.
Old Apr 2, 2006 | 07:50 AM
  #11  
1racerdude's Avatar
Banned
 
Joined: May 2003
Posts: 6,661
From: LA (lower Alabama)
Re: Another Knock issue

Put some 110/112 race fuel in it when the tank is very low.
There could be a number of things causing it but fuel will tell ya if its real knock.
Old Apr 2, 2006 | 09:26 AM
  #12  
Honda Hunter's Avatar
Thread Starter
Registered User
 
Joined: Sep 2005
Posts: 2,271
From: Bahrain
Re: Another Knock issue

Originally Posted by sssalah
The static CR is 12.23:1, with 5 cc pistons, a 0.039" gasket and assuming 55 cc chambers on the resurfaced AFR heads.
The IVC at 74 deg ABDC so that should put the DCR at 9.01:1.
I was just about to P.M ya
Old Apr 2, 2006 | 04:57 PM
  #13  
Fbody1's Avatar
Registered User
 
Joined: Feb 2000
Posts: 363
From: fl,jax
Re: Another Knock issue

the octane boost you are blending with your fuel probably only boost 3 to 7 points ( from 93 to 93.3 or 93.7) not going to make a lot of differnce. if your sc is 12.2 and the dcr is 9.01, try to get some toluene ( 114 octane) you can get a gallon from a paint store for like $12 , mix 1 gal of toluene to 2 gal of 93 to have 100 octane, try this it should not have any( knock) with this mixture, if it does it is false knock. if you cant find toluene get some xylene(117 octane) I've seen it at home depot, but add 3 oz of atf fluid to lube the fuel system( cause xylene is a little corossive to rubber seals) and the thing with putting teflon around the knock sensor can only help you.

Last edited by Fbody1; Apr 2, 2006 at 04:59 PM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dbusch22
Forced Induction
6
Oct 31, 2016 11:09 AM
99z28 carguy
LS1 Based Engine Tech
4
May 26, 2015 11:35 AM
BigWil
LT1 Based Engine Tech
12
Mar 29, 2015 12:24 PM
4586
LT1 Based Engine Tech
4
Mar 18, 2015 06:31 PM
HectorM52
Parts For Sale
4
Mar 15, 2015 10:45 PM




All times are GMT -5. The time now is 09:58 PM.