[Diy_efi] Knock Detection using GM ESC Module

[Programmer]

#4 piston happen to be the melter ?
Are you using a GM HEI, non mech advance, 7 pin module and ESC computer ?

Lyndon.

----- Original Message -----
From: "Ken Richardson" <krichar at ns.sympatico.ca>
To: <Diy_efi at diy-efi.org>
Sent: Wednesday, May 29, 2002 3:20 PM
Subject: Re: [Diy_efi] Knock Detection using GM ESC Module


> Melted tops and ring lands broke on one piston. It's clearly detonation.
We
> are limited to what we can do to the engine by our rules. We run a GM HEI
> distributor with MSD coil, 9.2:1 compression, fairly stock cam. Premium
fuel
> only.
>
> The engine ran A1 on the dyno for 20 to 30 pulls, everything looked fine.
We
> ran 1 heat race and a practice session before the race with no problems.
The
> plugs looked fine after the dyno pulls and heat race/practice. It almost
> seems the carb picked up some dirt during the race, although we didn't
find
> anything. Regardless, a knock detection device "might" have saved us,
that's
> why we put one on the engine. Now I'm wondering how much we should trust
it.
>
> Ken
>
>
>
> ----- Original Message -----
> From: "Programmer" <nwester at eidnet.org>
> To: <Diy_efi at diy-efi.org>
> Sent: Wednesday, May 29, 2002 12:13 PM
> Subject: Re: [Diy_efi] Knock Detection using GM ESC Module
>
>
> > "melted pistons" or broke off ring lands ? Detonation looks different
than
> > running lean. Which distributor are you running ? What compression, cam
> and
> > fuel choices ?
> >
> > Lyndon
> >
> > ----- Original Message -----
> > From: "Ken Richardson" <krichar at ns.sympatico.ca>
> > To: <diy_efi at diy-efi.org>
> > Sent: Wednesday, May 29, 2002 4:57 AM
> > Subject: [Diy_efi] Knock Detection using GM ESC Module
> >
> >
> > > We recently had one of our race engines fail due to a lean condition.
It
> > > basically detonated itself to death, melted 4 pistons until one
finally
> > let
> > > go. The engine ran fine on the dyno and in testing so we think it was
a
> > fuel
> > > restriction that caused it. We couldn't find anything so we're going
to
> > > richen the carb up and add some octane boost to the fuel to be on the
> safe
> > > side.
> > >
> > > I picked up a GM ESC module from an early 90's GMC truck, 5.7L. Our
race
> > > engine is a 350cid GM smallblock bored 0.060 oversized. I'm going to
use
> > the
> > > ESC module with a power transistor to drive a warning light on the
dash
> of
> > > the car. I haven't experimented with this before, it looks like it
> should
> > > work. Lightly tapping on the block with a hammer flashes the light.
Will
> > the
> > > ESC module/sensor consistently detect detonation at higher RPMs, in
the
> > > range of 3800 to 5800rpm? This is the RPM range we run the engine.
Will
> > the
> > > larger cylinder diameter throw the sensor tuning off enough that it
> won't
> > be
> > > reliable?
> > >
> > > We want to limit our chances of burning any more pistons. We got lucky
> > this
> > > time, no damage to the block, although the heads needed to be rebuilt
> due
> > to
> > > the aluminum buildup. It gets expensive not to mention working our
buts
> > off
> > > to get ready for the next race.
> > >
> > > Opinions??
> > >
> > > Thanks
> > > Ken R.
> > >
> > >
> > >
> > > _______________________________________________
> > > Diy_efi mailing list
> > > Diy_efi at diy-efi.org
> > > http://www.diy-efi.org/mailman/listinfo/diy_efi
> > >
> >
> >
> >
> > _______________________________________________
> > Diy_efi mailing list
> > Diy_efi at diy-efi.org
> > http://www.diy-efi.org/mailman/listinfo/diy_efi
>
>
> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> http://www.diy-efi.org/mailman/listinfo/diy_efi
>


_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi