Independent cylinder knock control

[Jim Pearl]

Would like to know more about these meters. Worse comes to worse I'll 
purchase a set of LEDS and a an IC to drive them. As for mounting it to the 
lower engine - this is a 5.0 Ford - no "stock" mounting boss exists.. I've 
got a 351W n the stand - I'll examine it and look for likely spots but I'm 
betting there won't be an easy one. Duttweiler told me to use the back of 
the head and provided a block of threaded aluminum to assist me in bolting 
it up, I used the front of the head on an accessory stud. I'm not running 
much advance and it does retard - pulling it off allows knock - rock and a 
hard place I guess. This is why I want to monitor it - to try and get an 
idea as to how much false knock it's getting. DFI provides no adjustment to 
the sensitivity and no way to monitor it save through a laptop. I'm tempted 
to buy one of the "boxes" available to monitor it but they're not cheap and 
I'm fairly certain their simple inside...

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>From: 	Frank F Parker[SMTP:fparker at umich.edu]
Sent: 	Friday, March 29, 1996 6:52 AM
To: 	diy_efi at coulomb.eng.ohio-state.edu
Subject: 	RE: Independent cylinder knock control


> I've heard of the J&S system - it sounded great and if not for my DFI.... 
> Currently I use a GM sensor hooked into my DFI. I was told to mount it on 
> the HEAD (!) and am pretty sure I'm getting false knock from the
> valvetrain. The sensor uses a small box from GM between it and the
> computer. I've seen monitoring boxes for turbo GNs and would love to 
adapt
> one for my system. Anyone have any ideas? I just want to know when it's
> thinking it sees knock without having to use my laptop. I've done some
> electronics work but it's been years and most of the little bit of design 
> knowledge I had has drained away.. TIA!
>
The mounting on the head is a very bad idea. Use the stock GM location
on the bottom of block near oil pan rail. The gm box is a crude bandpass
filter and works poorly-gives alot of false retard. A number of companies
sell a monitor which appear to be a stock gm sensor connected to simple
dc meter thru a diode.
Frank Parker
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