[Healeys] Spark Scatter over 4000rpm

[Andy Thorp]

Hi Alan,

If you are also a determined fiddler then it is not so difficult to install
the sensor once the trans is removed, probably about four hours work including
a trip to the bolt shop. There is a bit of complexity involved in setting up
the electronics if that isn't your area of expertise but it's not that hard.
It really won't give any real world advantage over the distributor though.

The sensor is a Honeywell 1GT101DC
Electronic timing is handled by a locally made Link G4 "Atom" ECU, as is the
fuel injection. Any ecu like Megasquirt would also do.

To position the sensor, take out one of the clutch cover bolts and use a snug
fitting drill to mark a location on the backing plate that will place the
sensor as far away from the sump as possible. The location I chose interferes
with the sump a little when taking the sensor out which is why you can see the
hole (11/16") is filed away to allow it to tip sideways slightly for removal.
You might be able to find a better location.

The clutch cover bolts need to be replaced with 1.5" long all-thread
(setscrew) ones so they stick out of the back for the sensor to read. The 5/16
threads in the flywheel also need the last few turns tapping so the bolts can
go all the way through. Then set the clearance for the sensor- I used a
handbrake lever spacer and two washers stacked up.  As the car is still
positive earth I can power the sensor from the hold-down bolt.
http://tinyurl.com/lpjavoa

Beware the slippery slope of trying to improve the early BN4 engine...
http://tinyurl.com/n6f8wvp

Andy.


--------------------------------------------
On Sat, 1/3/14, Bluehealey <bluehealey at gmail.com> wrote:

 Subject: Re: [Healeys] Spark Scatter over 4000rpm
 To: "Andy Thorp" <bce257 at yahoo.co.nz>
 Cc: "healeys at autox.team.net" <healeys at autox.team.net>, "Oudesluys"
<coudesluijs at chello.nl>
 Received: Saturday, 1 March, 2014, 10:22 AM

 Hi Andy
 I love that idea for a spark trigger, particularly the
 stealth nature of the install. Could you possibly write up
 how you implemented it? The components used, how the
 location was selected, how the timing was set and how the
 advance curve is managed?
 I have been considering something similar using a trigger
 wheel behind the front pulley on my BN4 but your solution
 has brilliant simplicity.

 Alan - from my iPad