-----Original Message-----
From: owner-healeys@autox.team.net [mailto:owner-healeys@autox.team.net] On
Behalf Of John Harper
Sent: 12 October 2006 18:03
To: Simon Lachlan
Cc: 'healey list'
Subject: Re: fuel pump points
Simon
I don't think that this statement about throw over is at all
meaningless. The reliable action of a pump depends entirely on the throw
over being correctly set. The diaphragm has to be rotated until whilst
pressing the centre the throw over fails. It then has to be turned back
to allow for slack, wear, diaphragm stretch and expansion etc.
Early instructions I believe said 4 holes but this has now been
increased in recent literature to 5 or 6. I know to my cost that the
early procedure gave problems. I had a pump that worked fine on the
bench but it would let me down when it got hot. I stripped it down three
or four times to try and find what was wrong. I then built a test rig
and pumped paraffin through at full flow rate for a long period. It took
over an hour before it failed and then I could see that there was no
throw over slack left. Then a colleague told me about the later
information. I just set the pump up accordingly and it has never failed
again after many hour of soak testing on the rig and road running over
the last four years or so.
Regards
What I meant was that the term "throw-over" is not adequately descriptive.
If one hasn't laid eyes on set of pump points in over 25 years, one won't
know when they're "throwing over", certainly not when they are throwing over
as they should be. It's a terminological thing.
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