FW: Electronic timing advance

[Bruce Plecan]

-----Original Message-----
From: Tom Parker <tparker at nznet.gen.nz>
To: HADJIASLANIS ARIS 1260 800 <diy_efi at efi332.eng.ohio-state.edu>
Date: Friday, January 22, 1999 4:28 PM
Subject: Re: FW: Electronic timing advance

Just as a minor point. The Italians have many many cars that get along
just fine without using a vac advance.  While USA/Eng/Asian have
relied on them for years, not so from across the other ocean.
And how many motorcycles bother with a vac advance?.
While a knock sensor sounds nice, a properly tuned would only need it
when junk gas is bought. They can also lure the owner into a false security.
Which I'm sad to say I'm finding happening way to often.

With a knock sensor no audible ping, so granny saves a few pennies here
and there on gas, but anytime she gets on it the timing retards, and carbon
builds
up unessecarily.  Enough builds, and eventually the little flakes break off
and hold an exhaust valve just slightly off it's seat. Valve runs too hot,
and
burns.  So granny never heard that she should have been running better
gas, since there was no ping, and now at 50K needs a valve job.
  If ya feel the need for running a KS, I'd strongly recommend a visual/
audible alert when it's triggered.
Bruce


>HADJIASLANIS ARIS     1260 800 <aris at exmail.panafon.gr> wrote:
>
>>after following your inputs and using the web as much as I could, I have
>>now found and ordered a XR 700 ignition unit from Crane Cams which WILL
>
>I have one of these in my Mini, they are pritty good.
>
>>My original posting to which you replied most kindly was ...
>>"... 3. Feed the optical pick up output to a digital advance / retard
>>unit
>>implementing a simple, programmable advance curve capable of at least 16
>>sites.
>>4. Optionally add an imput for a detonation sensor to provide a few
>>degrees of detonation induced retard.
>>5. The unit should just provide an output emulating a normal contact
>>breaker, to drive a separate high energy electronic ignition unit
>>(already fitted in my car)...."
>
>I am attempting to build the system that is on the diy_efi web page.
However,
>due to lack of funds, and the fact that my brakes don't work right, I
haven't
>made much progress beyond deciding to use an off the shelf single board
>computer and a custom interface board to go with it.
>
>I plan to extend the design to take note of a MAP sensor, maybe a TPS
sensor
>and maybe also a knock sensor.
>
>I looked at the picknpoke design (this is the kit that Jaycar in australia
>sell). It has a two stage advance curve. You can specify the steepness of
the
>advance in two lines. It doesn't have a very good (IMO) vacuume advance
>system, and the biggest problem is that you can't change the program
without
>reverse engineering it.
>
>Having said that, it is cheap, and it is available now.
>
>--
>Tom Parker - tparker at nznet.gen.nz
>           - http://www.geocities.com/MotorCity/Track/8381/
>